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Will looking at DNA help you see if the gene has been expressed or not?
Why is the nucleotide sequence of both the coding strand and the mRNA are complementary to the sequence of the template strand?
mRNA is transcribed from the template strand, so it will be identical to the coding strand except with U instead of T
What does Glucose 6-phosphate dehydrogenase catalyze the conversion of in the pentose phosphate pathway?
Glucose 6-phosphate dehydrogenase catalyzes the conversion of glucose 6-phosphate to 6-phosphogluconolactone in the pentose phosphate pathway
How does the ETC work?
The electron transport chain uses the free energy from redox reactions to pump protons from mitochondrial matrix to the intermembrane space thereby generating an electrochemical gradient across the inner mitochondrial membrane.
___________ is a cofactor for the enzyme pyruvate dehydrogenase which catalyzes the conversion of pyruvate to acetyl-CoA.
The Vmax of an enzymatic reaction is altered by which types of inhibitors?
Noncompetitive, uncompetitive, mixed
pentose phosphate pathway produces NADPH, which is a __________ agent
NADPH is a reductive agent
LEO GER (If there are hydrogens then it can lose electrons, which means that it undergoes oxidation, which means that the thing losing e- is the reducing agent)
increased activity of succinyl-CoA synthetase will result in greater levels of what?
the reaction products: succinate and GTP.
Succinyl-CoA is the substrate of the reaction and its levels will likely decrease with increased succinyl-CoA function.
what pathway is phosphogluconate is involved in?
the pentose phosphate pathway
glycogen is formed by what glycosidic bonds between glucose molecules?
through α(1→4) linkage linearly and α(1→6) linkage at branch points.
What is the enzyme that catalyzes the rate-limiting step in glycogen breakdown (glycogenolysis)?
Exposure to high glucose levels results in elevated levels of circulating insulin which prevents mobilization of endogenous glucose storage. How can this be reversed?
Infusion of glucagon will result in mobilization of endogenous glucose storage thereby preventing hypoglycemia and brain injury.
Can you use Acetyl-CoA as a precursor for gluconeogenesis?
No, you cannot use Acetyl-CoA as a precursor for gluconeogenesis because it combines with an oxaloacetate to make citrate. Therefore, even though you get back to oxaloacetate, you end up with a net gain of zero e.g. you use up an oxaloacetate to ultimately create an oxaloacetate. Oxaloacetate is ultimately the starting point for gluconeogenesis as it takes place inside our liver cells. If we have a precursor that gets us there then we are good. This is why alpha ketogluturate works. Lactate is a precursor for gluconeogenesis through the Cori Cycle where it is shuttled to the liver, then we make glucose there, then shuttle it back to the muscles.
Is RNA polymerase used in cDNA cloning?
DNA polymerase (in DNA amplification),
DNA ligase (in ligation of the cDNA to DNA vector) and
reverse transcriptase (in reverse transcription of RNA to cDNA) are used during cDNA cloning
True or False: At constant enzyme concentration, the highest catalytic efficiency is the enzyme with the smallest Km
True, catalytic efficiency = Kcat/Km
Which enzyme is used both in gluconeogenesis and glycogenolysis?
glucose 6-phosphatase catalyzes the final step of both gluconeogenesis and glycogenolysis
How many molecules of reduced electron carrier are generated during conversion of α-ketoglutarate to oxaloacetate in the citric acid cycle?
2 molecules of NADH and one molecule of FADH2 are generated
affinity chromatography separates proteins based on what?
their interactions with specific ligands
protein with a mass of 50 kDa is approximately composed of how many amino acid residues?
50,000/110 = 455 AA residues
the average molecular weight of an amino acid is 110 Da
What allows for the expression of isoforms of proteins
isoforms of proteins are expressed from single genes through alternative splicing of exons of the primary transcript.
What are the only elements that vary in different cells and therefore can confer both temporal and spatial regulation of their target genes?
These are a type of transcription factor, but not all transcription factors are nuclear factors
Nuclear proteins require what domains?
A nuclear protein requires a nuclear localization domain for nuclear translocation and a DNA binding domain for binding to regulatory regions of targeted genes.
Signal sequence domains are protein domains required for proteins that are directed toward secretory pathways.
What is present in the mitochondrial intermembrane space during normal cell function and is released into the cytoplasm when apoptosis is initiated?
transmembrane helices are made up of mostly unbroken stretches of ___________ amino acids.
_______________ inhibitors bind their target enzymes only when the substrate is first bound to the enzyme.
Since at higher substrate concentrations, the substrate-enzyme complex are more abundant, the uncompetitive inhibitor will work most effectively when the substrate concentration is the highest. Additionally, an increase in the inhibitor concentration results in increased enzyme binding and inhibition.
Which type of inhibitor does NOT alter the KM/Vmax ratio of an enzyme?
uncompetitive inhibitors do not alter the slope of the Lineweaver-Burk plot, which is equal KM/Vmax
_________________ bonds link adjacent nucleotides in DNA.
They do not contribute to the stabilization of protein structure!!
_______________ hormones are hydrophilic and soluble in blood.
What type of hormones must bind transport proteins?
steroid hormones, because they are lipophilic and not soluble in blood
Ovarian cells are _________ cells
osteoclasts are ___________ cells
best control against the variable of enzyme autophosphorylation would be what?
the enzymes alone without substrate.
How are different protein isoforms synthesized?
Different protein isoforms are synthesized from the same gene through alternative splicing, during which sections of the full transcript (both introns and exons) are spliced. Different combinations of exons can produce different protein isoforms.
What type of modification is alternative splicing?
alternative splicing is pre-translational/post-transcriptional modification
True or False: Arginine has amide groups
False, Arginine doesn't have amide groups... it just has lots of nitrogens. (glutamine and asparagine has amide)
noncompetitive inhibitors is that they bind the enzyme and the enzyme-substrate complex with the same affinity; Vmax is affected, but KM does not change.
high substrate affinity
What does Hill coefficient measure?
cooperatively between protein subunits
isoforms are produced through alternative splicing of pre-mRNA
Generating cDNA from mRNA will generate a sequence for each isoform
In a species of beetle, red body color is dominant to brown. Two red beetles are crossed and produce 31 red and 9 brown offspring (F1 generation). If two red F1 beetles are crossed, what is the probability that both red and brown beetles will appear in the F2 generation?
a 3:1 ratio of F1 offspring means that the original crossed beetles are both heterozygotes, and the F1offspring are 25% red (homozygous dominant), 50% red (heterozygous), and 25% brown (homozygous recessive). If two red F1 beetles are crossed and both red and brown beetles appear in the F2 generation, the F1 red beetles that were crossed must both be heterozygotes. The probability that, of the red F1 beetles, both were heterozygous is 2/3 × 2/3, or 4/9 (only red beetles were selected from and 2/3 of the red F1 beetles were heterozygous).
What organ secretes glucagon?
What organ detox drugs?
Gel electrophoresis types
Denaturing = will disrupt the interactions between monomers; Reducing = disrupt disulfide bonds; Native = use this if you do not want to disrupt the tertiary structure
What is the average molecular weight of an amino acid?
rate experiments by applying the principles of the Michaelis-Menten equation
By keeping enzyme concentration constant, varying substrate concentration, and either including or excluding the inhibitor, the effect of the inhibitor on the Vmax and apparent Km of the reaction can be determined.
mRNA transcribed from retroviral DNA is used to?
either used to synthesize viral proteins, or used as the RNA genome for progeny viruses. Thus, the sequence of the nucleotide in the original viral genome will be the same as that of the transcribed mRNA.
The only bond that phosphorus has with any molecule within DNA is _______
oxygen. The 3' OH group binds with the 5' P
A single point mutation in a gene results in a nonfunctional protein. Individuals heterozygous for this mutation were identified using ________________
Southern blot uses a restriction digest to differentiate between mutant and wild-type alleles. In order for a Southern blot to be useful, the mutation should either create or eliminate a restriction site, most of which are palindromes and 4 to 6 base pairs long. (e.g. Palindromic sequence = AAGCTT)
Re-entry of Ca2+ back into the sarcoplasmic reticulum uses ____________
Ca2+ ATPase, an active pump, to bring Ca2+ back into SR against the concentration gradient so it is not a ion channel, since ion channel is involved in passive diffusion. This is a primary active transport
epimers v.s. enantiomers
Enantiomers and epimers are stereoisomers. Epimers are different from each other in their configurations at only one chiral carbon. Enantiomers have opposite stereochemical configuration at all the chiral centers within the molecule. The main difference between enantiomersand epimers is that enantiomers are mirror images of each other whereas epimers are not mirror images of each other.
Which amino acids can be phosphorylated?
Only amino acids with hydroxyls in their residues can be phosphorylated, as phosphorylation requires the formation of a phosphoester. Of the alpha amino acids, serine, threonine and tyrosine all have hydroxyl function groups.
Actin is what type of filament
intermediate filament example
kinase v.s. phosphatase v.s. phsosphorylase
kinase = adds phosphate from ATP; phosphatase = removes phosphate; phosphorylase = adds inorganic phosphate (HPO4)
Embryonic mouse cells divide every 10 hours at 37oC. How many cells would be produced from an egg after three days?
starting with a single egg, x cells would be present after three days (or 24 x 3=72 hours). The number can be calculated by tracking the doubling time: 1 → 2 → 4 → 8 → 16 → 32 → 64 → 128 . At the end of 70 hours (approximately 3 days), there would be 128 cells, assuming that each cell underwent division 10 hours after its previous division.
Pancreas produces what enzymes
The pancreas produces several proteolytic enzymes, which are released into the small intestine where they are converted to their active forms of trypsin, chymotrypsin, and carboxypeptidase.
If the blood flow to an alveolus were blocked what would happen?
there would be no flow of hemoglobin-rich red blood cells to take away O2 and no influx of CO2 from the blood. As a result the air in the alveolus would become more like that of the atmosphere. It would acquire a higher PO2 and a lower PCO2.
In comparison with the wall of the right ventricle of the heart, the left ventricular wall is:
the left ventricle has a thicker wall and develops more pressure than the right. The right ventricle pumps blood through the lungs. The left ventricle pumps blood through the entire rest of the body. The difference in the size of the lung compared to the rest of the body suggests that the left ventricle develops more pressure and has a thicker wall than the right. The organs through which the left ventricle pumps blood are farther away from the heart than the lungs and resistance in a tube is inversely proportional to the length of the tube. This would also suggest a thicker wall for the left ventricle and greater pressure.
Blood in the pulmonary artery v.s. aorta
Blood in the pulmonary artery is lower in oxygen, higher in CO2 and has a lower pH than arterial blood in the aorta. This is because the blood in the pulmonary artery, unlike blood in other arteries, is essentially the same as venous blood.
Breakdown of glucose proceeds first by glycolysis, then by oxidation in the citric acid (Krebs or tricarboxylic acid) cycle. The enzymes for the former process are located in the cytoplasm and those for the latter are in the matrix of mitochondria.
Where does transcription occur in prokaryotic cells?
Prokaryotic cells do not contain nuclei, membrane-bound organelles in which nuclear genes are transcribed in eukaryotic cells. Consequently, transcription occurs in the cytoplasm of bacterial cells.
bacteria v.s. viruses in relation to hosts
Bacteria do not require host tissue to reproduce, whereas viruses do.
Phagocytosis depends on what part of the cytoskeleton?
Phagocytosis requires that the cell change shape dramatically as it surrounds and engulfs large extracellular particles. Microtubules are one of the cytoskeletal elements that help determine cell shape. This function relies on the ability of the microtubules to disassemble and reorganize.
Endocrine v.s. exocrine
Exocrine glands secrete their products through ducts; endocrine glands release their products into the bloodstream.
support and nourish the spermatocytes and promote the process of spermatogenesis. Stimulated by FSH
osteoblasts v.s. osteoclasts
Osteoblasts, which form bone, and osteoclasts, which resorb it
Calcitonin v.s. parathyroid
Calcitonin forms bone (released in response to high blood calcium levels)
Parathyroid breaks down bone
True or False: FAD and NAD+ directly donate electrons to the electron transport chain
False, FAD and NAD+ do not directly donate electrons to the electron transport chain—it is their reduced forms that do.
Hemophilia, a disease in which the time required for blood to clot is greatly prolonged, is determined by a sex-linked gene. Suppose a man with normal blood clotting marries a woman with normal blood clotting whose father was a hemophiliac. If this couple has three sons, what is the probability that hemophilia will be transmitted to all three of them?
The woman inherited one X chromosome from her father and one from her mother. The father only had one X chromosome to contribute and that X chromosome contained the hemophilia gene. The mother will pass on one X chromosome to her sons, either the X chromosome containing the normal (wild type) gene, or the X chromosome containing the hemophilia gene. The probability of a son receiving the hemophilia gene and being a hemophiliac is 1/2, because there is a 50-50 chance that this son received an X chromosome carrying the defective gene from his carrier mother. The cumulative probability of all three sons inheriting the hemophilia gene would be the product of the individual probabilities, or 1/2 × 1/2 × 1/2. Thus, answer choice A, 1/8, is the answer.
divergence of one species into multiple species over time, which can occur when subgroups of the original species are separated or isolated in different environments so that these subgroups evolve independently of one another.
What part of a protein do autoimmune diseases affect?
if a disease is autoimmune, then it affects the surface of proteins encoded by the genes for the disease
Normally the immune system avoids attacking the tissues of its own body because:
The immune system is designed to attack foreign material in the body. It avoids attacking tissues of its own body because it suppresses cells that are specific to its own body's antigens (surface molecules that would otherwise initiate an immune response).
If blood pressure doubled and the resistance to blood flow increased by 50%, the amount of blood pumped by the heart would have:
P = CO × VR... it would increase by 1/3
reduced flow of blood through the renal arteries would cause?
would cause a decrease in glomerular blood pressure. The kidneys respond to this drop in pressure by activating the renin-angiotensin system of hormones. This increases the amount of sodium and water that is reabsorbed by the kidneys, therefore increasing blood volume and pressure.
The glomerular filtration rate is proportional to the glomerular capillary blood pressure minus the sum of the plasma osmotic pressure and the Bowman's capsule hydrostatic pressure. An increase to the systemic blood pressure would initially increase the glomerular capillary blood pressure, which would increase the glomerular filtration rate.
arteries > capillaries > veins
The need to conserve water in the body would lead to an increase in aldosterone secretion that would promote the retention of sodium ions. The retention of sodium ions would in turn promote the osmotic reabsorption of water by the kidneys
Antidiuretic hormone (ADH or vasopressin) secretion would increase to enhance the permeability of the distal tubules and collecting ducts of the kidney to promote water reabsorption and excretion of more concentrated urine.
All of the mitotic divisions that form primary oocytes occur when?
prior to birth
Most viral proteins are produced directly by:
translation of viral (NOT HOST) nucleic acid
Virus structure cannot be visualized with a light microscope. The limit of resolution of a light microscope is about 200 nm. They are smaller than bacteria and eukaryotic cells
One of the characteristics of viruses is that they are obligate intracellular parasites. They are unable to reproduce without the aid of the host cell's metabolic machinery.
Many viruses form infective particles (virions) by budding off the surface of eukaryotic cells and becoming enclosed in a vesicle composed of the host's cell membrane. Such eukaryotic cell membrane is made up of a bilayer of amphipathic lipids with associated proteins.
Multiple pathways to ganglia lead to _________ (faster or slower?) response of the sympathetic system. Multiple pathways are also more consistent with a systemic, rather than localized, response.
The parasympathetic nerves to the iris release _______________ onto the circular muscles causing pupillary constriction.
What is a major component of the bacterial cell wall
contraction of the _____________ rib muscles helps the chest expand
A stable, differentiated cell that will NOT divide again during its lifetime would most likely be found in what stage of the cell cycle?
A diploid, nondividing cell is most likely in G0 or G1, in which the cell remains metabolically active but is not replicating its DNA (S) or segregating its duplicated chromosomes and dividing (M).
In starvation, the body uses up its stores of carbohydrate and lipids, and then begins to break down body proteins for metabolic energy. A byproduct of the metabolism of the amino acids from protein is nitrogen.
ribosomes v.s. chromosomes
ribosomes = rRNA and proteins
chromosomes = DNA and proteins
True or False: RNA is found in the nuclear membrane
False, RNA is not found in the nuclear membrane
After meiosis, human germ cells contain half the genetic material of other cells in the body, but they still retain one copy of each gene. The normal complement of genes is re-established at fertilization, before development of the embryo begins.
_____________ ions maintain proper physiological pH, or the level of hydrogen ions
blood flows from arteries to capillaries and then to veins. If flow is blocked at the venous side, blood would accumulate in the capillaries. Thus, hydrostatic pressure would build up in the capillaries, causing a net increase in fluid flow into the interstitial spaces
People who have diabetes mellitus have a difficult time controlling blood glucose levels because of impaired production of or response to insulin, resulting in increased blood glucose. Drugs that further increase blood glucose levels by activating beta-adrenergic receptors would aggravate this diabetic condition.
absorption of NT into nerve terminal
What directly inhibits peristalsis and secretion of digestive enzymes?
It also increases the blood glucose concentration and causes dilation of the blood vessels that supply the deep muscles and internal organs, which aids nutrient delivery to these tissues. The sympathetic nervous system does not directly affect the activity of digestive enzymes after they have been secreted.
Oxidative phosphorylation in eukaryotes v.s. prokaryotes
The inner membrane of a mitochondrion is analogous to the plasma membrane of a prokaryote. The enzymes for oxidative phosphorylation are embedded in the inner membrane. The endosymbiotic theory suggests that mitochondria are descendents of prokaryotes that were engulfed by endocytosis into a vesicle lined with a membrane derived from the cell membrane of the eukaryote host. This is the outer membrane.
Following the antibiotic treatment, the patient's colon will be recolonized by other bacteria. The factor that will ultimately determine whether antibiotic-resistant E. coli cells will persist in the colon at this time is E. coli's ability to:
produce more descendants than do the other bacteria... Pertains to E.coli persistence in the environmental niche of the colon (directly related to ability to produce progeny)
is continuous with the colon so that bacteria can move between these two structures; a ruptured appendix would allow E. coliinto the abdominal cavity
Mutations which make cells drug resistant are very rare, but the few drug-resistant bacteria that do develop such mutations flourish when the nonresistant cells are killed by antibiotics. Antibiotics are unlikely to have been the source of the mutations; nor do bacteria develop "immune" reactions to antibiotics. Chance mutations in bacteria (causing antibiotic-resistance) are made before treatment
Within a sarcomere, the microfilament length remains stable. Because one end of the microfilament is anchored in the Z line, actin monomers are prevented from being added to or subtracted from that end. Therefore, to retain a stable length, both ends of the microfilament must be capped.
The outer layers of human skin are composed of dead cells impregnated with keratin and oil, which make the epidermis relatively impermeable to water, yet humans sweat freely in hot temperatures. This occurs because:
The sweat glands secrete onto the surface of the skin through channels continuous with the most superficial layer of the skin, the epidermis. These channels prevent water loss by isolating the water-permeable, sweat-secreting cells from dry surface air. The openings of the sweat glands on to the surface of the epidermis are pores.
In eukaryotic cells, the process of incorporating uridine nucleotides into nucleic acid polymers occurs in which of the following structures of the cell?
Question is asking where transcription occurs (because this is where uridine nucleotides are incorported into RNA)... the nucleus
characteristic that differentiates growing, developing long bones from adult bones
Cartilaginous areas in long bons of growing children. Long bones grow via endochondral ossification, which requires cartilaginous growth plates at the ends of long bones, that thicken as cartilage and later become ossified
Kidney failure during severe dehydration is most likely due to:
inadequate blood volume for effective filtration. Severe dehydration greatly reduces the volume of filtrate moving through the nephrons of the kidney. If fluid volume is too drastically reduced, the kidney will be unable to effectively do its job of filtering and maintaining homeostasis within bodily fluids.
True or False: The organism with the highest body temperature in a desert will be the one incapable of vasolidation and sweating for cooling (e.g. because they lack sweat glands)
vasodilation = radiation
What triggers LH surge?
What is secreted in response to LH surge?
What hormone triggers ovulation
LH (luteinizing hormone)
The ____________ develops from a bulge on the side of the developing brain, which influences the overlying ectoderm to produce the lens. It is therefore an example of cells inducing neighboring cells to differentiate
What is the net volume of fresh air that enters the alveoli each minute, assuming that the breathing rate is 10 breaths/min, the tidal volume is 800 mL/breath, and the nonalveolar respiratory system volume (dead space) is 150 mL?
The amount of air entering the lungs in a single breath, or tidal volume, is given as 800 mL/breath. Of that 800 mL only 650 mL reaches the alveoli per breath (800 mL of air inhaled minus 150 mL of nonalveolar respiratory volume). Therefore the net volume of air that reaches the alveoli each minute is equal to 650 mL/breath multiplied by 10 breaths/min, or 6500 mL.
True or False: Skeletal and cardiac muscles contain striated muscle fibers.
True, Smooth muscles do not.
the movement of K+ into the mitochondria would disrupt what?
disrupt proton movement into the intermembrane space, decreasing the rate of ATP synthesis (bc concentration gradient would be affected)
Changes in the ___________ of the DNA molecule would involve substantial changes in the way the molecule replicated and the way it was transcribed.
topology (properties that are preserved through deformations, twistings, and stretchings of objects)
Anaerobic prokaryote phagocytised aerobic prokaryote and they entered a symbiotic relationship. The aerobic prokaryote became mitochondria inside of the anaerobic prokaryote, which then became a eukaryote. (Mitochondria genes were not acquired by host cell nucleus, because they do extranuclear replication)
prokaryotes that entered a symbiotic relationship with other prokaryotes to form what would eventually become the first eukaryotes. lateral transfer of genes from one genome to another is widespread among living organisms. It would have been an easy matter for mitochondrial genes to be acquired by the host cell nucleus and to disappear from the mitochondrial genome. It is likely that this exchange would have resulted in a net gain in efficiency for the composite organism.
dermis is derived here but not epidermis (ectoderm)
In which organelle of a eukaryotic cell is the pyrimidine uracil, as part of uridine triphosphate (UTP), incorporated into nucleic acid?
The nitrogenous base, uracil, combined with the sugar ribose and phosphate makes up the nucleotide uridine. It is found in RNA, but not in DNA. The corresponding DNA nucleotide is thymine. Uridine is incorporated into RNA in the nucleus where transcription of DNA into RNA takes place. RNA is manufactured in the nucleus from a DNA template. RNA is necessary for protein synthesis by free ribosomes and those attached to endoplasmic reticulum, but it is not synthesized there.
double stranded daughter DNA molecule
exact duplicate of the parent molecule
The sequence of events in the human menstrual cycle involves close interaction among which organs?
The hypothalamus exerts control over the pituitary hormones involved in menstruation by secreting hormone-releasing factors into the pituitary portal circulation. The gonadotropic hormones FSH and LH produced by the pituitary and the ovarian hormones estrogen and progesterone all have a role in regulating the human menstrual cycle. Therefore, close interaction among the hypothalamus, the pituitary, and the ovary is necessary for the human menstrual cycle.
Two organisms are considered separate species if they are not able to successfully breed and produce fertile offspring.
Species are separated from one another by prezygotic and postzygotic barriers, which prevent mating or the production of viable, fertile offspring.
Autosome v.s. Sex Chromosome
Sex linked genes only appear on the 23rd pair of chromosomes. Autosomal genes are related to the other 22. Autosomal is where you don't use X or Y when creating Punnett squares because sex isn't a factor. Rule of thumb: if male progeny have a trait at different levels than female progeny, the trait in question is sex linked. If males and females have the trait at the same frequency, then it's autosomal.
What would be the result of complete removal of the parathyroid glands?
Removal of the parathyroid gland would lead to hypocalcemia, a condition of low blood calcium, resulting from the lack of parathyroid hormone. This would cause increased neuromuscular excitability because of the change in membrane potential, which under normal physiological conditions, is partially kept in balance with extracellular calcium. Typically, the person would eventually die from severe respiratory muscle spasms.
gets released from thyroid hormone and reduces bone resorption and promote osteoblast activity (bone formation). Bone resorption occurs when the level of calcium in the blood plasma is low, but resorption is not needed when the level of calcium is high. Therefore, resorption would be reduced by calcitonin under conditions in which the level of calcium in the plasma is high.
Parathyroid hormone will increase the number of osteoclasts, which break down bone cells. PTH and osteoclasts both wor to increase blood calcium levels
acts on the small intestine to stimulate the absorption of calcium into the bloodstream. Enhances the effect of PTH
promote the breakdown of bone tissue (to promote calcium levels in the blood plasma), causing the bones to become weak. If there were a metabolic deficiency of parathyroid hormone, the body would be unable to break down bone tissue, causing a higher than normal ratio of mineral to organic matter in the bones
Most bacterial cells and human cells are alike in
the ability to produce ATP via ATP synthase is common to both bacterial and human cells. Both types of cells possess a membrane-embedded electron transport chain capable of generating a H+ gradient, which drives synthesis of ATP via ATP synthase. This ATP synthesis takes place on the plasma membrane of bacteria and on the inner mitochondrial membrane in human cells.
True or False: Prokaryotic ribosomes are different from eukaryotic ribosomes, even though both organisms have ribosomes
Prokaryotes: 30S+50S = 70S
Eukaryotes: 40S+60S = 80S
Cyclins are highest at the beginning of mitosis and gradually declide during mitosis, reaching a minimum at the end of mitosis, and gradually increasing during interphase. Why is this?
The mechanism that can best account for this oscillation in the concentration of cyclin is translation of cyclin mRNA (creating the protein from mRNA template) followed by proteolysis (destruction) of cyclin protein during mitosis.
produced by the adrenal cortex, and causes Na+ reabsorption by kidney tubules (decreases Na+ levels in the urine)
Osmoregulatory plasma protein (note that plamsa proteins cannot cross the walls of blood vessels). An increase in plasma albumin will upset the osmotic balance because the blood will become hypertonic with respect to the tissue. Water will have to flow into the bloodstream to reestablish equilibrium. One of the causes of edema, increased fluid in body tissues, is a decrease in the plasma protein level. This occurs, for instance, in starvation when the body is forced to use its albumin as an energy source.
three-dimensional structure of a protein is stabilized by covalent bonds and noncovalent interactions between different regions of the linear peptide. This three-dimensional structure can be disrupted by heating or by changing the pH. The disorganization of proteins by such agents is called denaturation. Enzymes are proteins that act as organic catalysts, speeding chemical reactions but not being consumed in them. Their function is highly dependent on a precise three dimensional structure, especially at the site of catalysis, known as the active site.
True or False: Mutations are in the CHROMOSOME
Mutations are heritable changes in the sequence of the nucleic acid component of chromosomes, and mutations that lead to unregulated cellular growth can lead to cancer. Damaging histones would not cause cancer
detoxification of poisons and the production of bile, which facilitates fat absorption in the small intestine by breaking large fat droplets into smaller ones
Uncoupling of ATP production from oxidative metabolism would reduce ATP synthesis in the mitochondria
This could affect sperm motility, since there is lots of mitochondria (which produces ATP) in the midpiece of sperm
Increased vasoconstriction is imporant for maintaining blood pressure during a hemorrhage
As blood is lost from the circulation, reduction in vessel size helps maintain the necessary pressure to keep the blood circulating to all body tissues. Vasoconstriction, the narrowing of a vessel, restricts blood flow to an organ and can increase blood pressure
The two primary factors that normally determine the level of blood pressure are:
the cardiac output and the resistance to blood flow... Cardiac output (stroke volume x heart rate) determines the amount of blood pumped into the system by the heart per unit time. The resistance to blood flow is primarily determined by the caliber of the small arteries, arterioles, and precapillary sphincters. Thus blood pressure equals total peripheral resistance times cardiac output, a relationship analogous to Ohm's law for electrical circuits.
If tissue is 10x more sensitive to a certain subtance, then that means it can be stimulated by that substance at 10x lower concentration
10^-6 is more concentrated than 10^-8
Increasing blood pressure should have what effect on GFR?
Increasing blood pressure should increase flow of fluid through the kidney system and decrease water reabsorption...
Increased BP will increase GFR, allowing less time for reabsorption
What is the source of the energy that forces fluid into the capsular space?
Blood pressure is the source of the energy that forces fluid into the capsular space. If the heart stopped and the blood in the glomerular capillaries had no hydrostatic pressure, fluid in the space around the glomerulus would flow back into the capillary bloodstream. This would occur because the protein-rich blood would be hypertonic with respect to the protein-poor fluid in the capsular space so that the fluid would flow down the osmotic gradient into the blood.
The amount of glucose in the fluid in the capsular space as it enters the tubule system would be the same as the amount of glucose in the plasma, but by the time the fluid reaches the distal tubule much of the glucose will have been reabsorbed. If the amount being filtered per minute is less than Tm, all of it will have been reabsorbed. If it is more than Tm, then the amount will be linearly related to the amount in the plasma. In the case proposed in this question, the amount being filtered per minute (125mg/min) is less than the Tm for glucose given in the passage (320 mg/min), so all of the glucose should be reabsorbed.
What is Tm in terms of the kidneys?
The Tm is a characteristic of the individual substances in the tubule system and a measure of how efficiently each substance can be reabsorbed. A high Tmindicates a high capacity for reabsorption of substances in the kidney tubules. This is the concentration in plasma when the concentration in urine is 0
The glomerulus is a group of capillaries that bulges into the capsular space (aka Bowman's space), which is a potential space lined with simple squamous epithelium. Fluid is expressed from the blood across the capillary endothelium. It enters first the capsular space, then the kidney tubule. The part of the tubule closest to the glomerulus is the proximal tubule, the next part is the U-shaped loop of Henle and the last part of the tubule is the distal tubule. Suppose one gradually increased the rate at which fluid was expressed from the bloodstream (the glomerular filtrate rate) and measured the concentration of some substance reabsorbed by the kidney as it left the distal tubule as urine. The concentration might not rise at first, because the cells lining the tubule might be completely reabsorbing the substance and putting it back into the blood stream. Eventually, however, the rate of flow would reach a point at which it exceeds the rate at which the tubule cells could reabsorb the substance. The fluid would be flowing too rapidly through the tubule for the cells to reabsorb all the substance. The rate of flow through the tubule at which the substance begins to be observed in the urine is Tm. At that point the rate of flow of fluid through the tubule begins to exceed the capacity of the kidney tubule cells to reabsorb the substance.
Deleterious genes are generally rare because they tend to be eliminated through natural selection. Only when an organism is homozygous (has two copies of a gene, one from each parent) does a recessive gene reveal its presence. Because recessive genes can be masked by dominant genes, they are less exposed to natural selection. So most organisms carry many deleterious recessive genes. The chances of having offspring that are homozygous for a given recessive gene are rare when a mate is chosen randomly from the population. The chances of getting a pair of deleterious recessive genes increase enormously when the mate is a relative, because relatives are likely to have a similar genotype.
Mitosis v.s. Meiosis
key differences between mitosis and meiosis occurs during their respective anaphases. During anaphase of mitosis, sister chromatids are pulled apart at the centromeres, each becoming an independent chromosome in the two diploid daughter cells. During anaphase I of meiosis I, homologous pairs of chromosomes are separated into the two daughter cells. However, each chromosome still consists of two sister chromatids joined to each other at the centromere. It is not until anaphase II of meiosis II that the centromere is split and the sister chromatids separate.
True or False: Ribosomes are organelles
False, not considered organelles. They are macromolecules that do not contain a membrane and are found in both prokaryotes and eukaryotes
increased urine production can be explained by ?
increased urine production can be explained by an increased blood pressure caused by adrenaline, released in response to excitement or anxiety—the fight or flight response.
True or False: the coordination of cell differentiation during development is extremely sensitive to the timing of mRNA turnover
mRNA that is facing the right direction, i.e. can be translated to form protein. If a drug blocks the sense mRNA, the only process inhibited is RNA translation.
Is it possible for a 45-ploid nucleus to be divided equally?
No, because it not possible for it to be separated into 22.5 chromosomes in each daughter cell. The daughter cells will have 22 and 23 chromosomes, respectively. This, the alleles will vary in the daughter cells
Does crossing over occur in binarry fission?
No, crossing over only occurs during meiosis
What does 45-ploid cells mean?
If haploid cells have one copy of each chromosome and diploid cells have two copies of each chromosome, then one can infer that 45-ploid cells have 45 copies of each chromosome. This is polyploidy (having ore than 2 copies of each chromosome)
Vertebrate Oocyte division
is uneven, because one daughter cell becomes the ovum and the other daughter cell becomes a polar body (both have the same amount of nuclear material but UNEVEN CYTOPLASM distribution... uneven RNA distribution is extranuclear)
In the cell cycle, S phase:
has to do with synthesis of DNA... So an extra S phase would result in additional doubling of the DNA. This would only minimise fluctuation if DNA levels were low.
must self-replicate to be passed from one generation to the next... has no impact on function
Inflation of lungs
accomplished by negative pressure pumping (lung pressure is lower than atmospheric pressure)
genes are transferred by a virus
bacteria take up DNA from their surroundings
one bacterium produces a sex pilus and transfers DNA through it to another bacterium. The formation of this sex pilus depends on the F factor plasmid. Plasmid benefits from being able to move between two host bacteriums. Conjugation is a feature of Gram-negative bacteria. Considered sexual reproduction of bacterium.
True or False: Enzymes interact with several differen substrat molecules that have similar chemical linkages.
What type of molecule are fats?
How do you increase water loss through the skin?
The only way to increase water loss through the skin is to change environmental temperature
rupture of red blood cells
What does hyperglycemia (high blood glucose) cause?
causes insulin secretion and glucagon inhibition
animals that can permit some freezing of its body fluids (aka ice in the extracellular fluid ONLY... NOT in cytoplasm = this is lethal) and sustain life
Freezing of body fluids
gradual process where watr moves osmotically out of cells into the concentrated unfrozen extracellular fluid. Thus, ice formation is restricted to extracellular water (ice crystal formation within cells is lethal because it disrupts structural organization). Glucose can act as an antifreeze by lowering the freezing point of body fluids by raising the osmotic pressure of the extracellular space.
leads to an innate response, where leukocytes (WBC) fight infection
Antibodies are secreted into extracellular spaces. They are part of plasma in the vascular system.
Function of antibodies
enable WBCs to fight off bacterial infection
Proten function in stomach
The stomach has a low pH, and antibodies are a protein. It is reasonable to assume that the protein has decreased function at sub-optimal pHs.
Cancer is caused by proliferation of ____________ cells
Can TCA and ETC occur without oxygen?
occurs in the cytosol and can occur under both anaerobic and aerobic conditions
Increasing the volume of air that reaches the alveoli and takes part in gas exchange will what what effect on pH?
It will enhance O2 uptake and CO2 removal (the partial pressure of CO2 will decrease), thereby increasing blood pH.
region on the surface of an antigen that binds one specific antibody. A molecule with several epitopes will bind several distinct antibody molecules. The presence of several antibodies on the surface of an antigen is expected to elicit a stronger immune response than if fewer antibodies were present.
True or False: Eukaryotes do not have peptidoglycan in their cell walls
Gibbs free energy equation
True or False: Tryptophan has an aromatic R group
Can Polar amino acids cross the phospholipid bilayer?
No, they cannot readily cross the phospholipid bilayer of the cell membrane, so they must be embedded in the cell membrane to facilitate transport of other molecules
Platelets are formed by megakaryocytes.
Platelets are cell fragments without nuclei... they consist of plasma membrane-encased megakaryocyte cytoplasm, which contains ribosomes
platelets for a plug at the site of blood vessel damage... inactive blood clotting factors are synthesized in the liver
Glucose impact on coagulation
glucose and insulin stored/produced by the liver affects the activation of platelets during coagulation, but the liver and platelets do notact together in energy homeostasis
The liver plays an important role in energy homeostasis by storing glucose in the form of glycogen under conditions of glucose excess and by breaking down glycogen and releasing glucose into the bloodstream under conditions of glucose limitation. The liver also synthesizes glucose from non-carbohydrate molecules.
Synthess of Cholesterol
Can occur in the liver and platelets, but these processes do not work together
True or False: Lysine (basic, positively charged AA) in Histones are likely to interact with negatvely charged phosphate groups on DNA
Histones do not interact with DNA in a sequence-specific manner
Insertion v.s. Translocation Mutations
Both are chromosome mutations
Insertion = segment of DNA is moved (added/subtracted) from one chromosome to another
Translocation = segment of DNA is swapped with a segment from another chromosome
Missense v.s. Nonsense Mutations
Both are nucleotide mutations
Missense = substutute one AA for another
Nonsense = substitue a stop codon for an AA
Platelets and erythrocytes are derived from progenitors in the ____________
True or False: prokaryotes do not undergo mitosis
True, they do binary fission
True or False: active transport is faster than diffusion
True or False: bacterial do not have endoplasmic reticulum or vesicles
75% protein and 25% phospholipid, by mass... They do not contain glycolipids or sterols
lactic acid fermentation electron acceptor
NADH reduces pyruvate to produce lactate and regenerate NAD+, which allows glycolysis to continue... pyruvate is the elctron acceptor in the production of lactate
aerobic respiration electron acceptor
oxygen is the electron acceptor for aerobic respiration... Water forms when electrons are passed to oxygen through a chain of carriers in the mitochondria
True or False: oxidative respiration requires lots of mitochondria and capillaries
nucleophile atom on methionine?
because sulfur is the only atom in the methionine side chain that has lone pairs of electrons available, it is a better nucleophile thsn other atoms on methionine
reduction of disulfide bonds
requires two electrons and each molecule of NADH can provide two electrons when reducing another compoud
When transitioning a hydrophobic amino acid from the interior of a soluble globular protein to the surface, it is associted with a large positive free energy (because it is not favorable to move a hydrophobic molecule to a hydrophilic environment)
the presence of a disulfide bond between two subunits of a protein would cause the protein to have a different elution time on a size-exclusion column
If a reducing agent decreased the elution time, then its likely that a disulfide bond was present
diunsaturated acyl chain
two double bonds have removed 4 hydrogen atoms
allows larger molecules to pass more freely through the column matrix and hinders the passage of smaller molecules
NOTE: Urea is smaller than 10kDa
measure of the amount of enzyme per miligram of total protein. Provides a measure of the purity of an enzymatic miture
which protein has the highest affinity of its ligand
the protein with the lowest binding dissociation constant has the highest affinity for its ligand
highest for basic amino acids (arginine and lysine)
Is pyruvate part of the TCA cycle?
No, pyruvate is not part of the TCA cycle, because it is converted to acetyl-CoA first
Things that happen during apoptosis
cytochrome c is released from mitochondria, cell shrinks/blebbs, caspase activation
apoptosis v.s. necrosis
apoptosis = programmed cell death
necrosis = caused by external factors such as trauma or infection (in necrosis, there may be damage to nearby cells caused by lysis... this does not happen in apoptosis)
alpha subunit binds GTP (GDP gets exchanged for GTP)
free energy during phosphate transfer
more negative free energy (-ΔG) = spontaneous phosphate transfer
unsaturated lipids do not pack well, and high temperatures cause more fluidity/movement/disorder
glycolysis NADH yield
each cycle of glycolysis produces two NADH molecules and requires an input of one glucose molecule
What is the dependent variable in the michaelis-menten enzymatic assays?
initial velocity because that appears on the y-axis
Variables on graphs
y-axis = dependent variable, x-axis = independent variable
if negative, then amino acids are hydrophilic/ if positive, then amino acids are hydrophobic... AA that are hydrophobic are more likely to reside within the plasma membrane
High Km and unchanged Vmax; binds to same site as substrate (competes for active site)
SDS-PAGE under reducing conditons
will separate two proteins if one has disulfide bonds and the other one doesn't
allows for 2-way exchange between the nucleus and cytosol
divides independently of nucleus (extranuclear inheritance) via binarry fission... (semiautonomous)
used for lipid synthesis and detoxification... transports proteins from RER to Golgi
break down long chain fatty acids (beta-oxidation), phospholipid synthesis and pentose phosphate pathway
inorganic component of bone (deposits of calcium phosphate = Calcium, phosphate, hydroxyl groups)
Epinephine is secreted by?
glycolysis ATP yield
The overall glycolytic pathway yields two ATP molecules, but in order to gain these two ATP molecules by the end of the process, some ATP must be consumed at the beginning. The first reaction, the phosphorylation of glucose, for instance, requires ATP. If this is lacking in the reaction mixture, glycolysis will not be initiated. Once initiated with a small amount of ATP, however, more ATP is produced and the reaction will become self-sufficient.
increases water permeability of the collecting duct and distal tubule by inserting aquaporins in the plasma membrane
Passage of fluid from the blood through the walls of the glomerulus depends on:
hydrostatic pressure of the blood in the glomerular capillaries
translation of antibody proteins
occurs at ribosomes associated with the endoplasmic reticulum
clear cell and tissue debris and foreign objects from the body (by engulfing extracellular material = phagocytosis)
form bone tissue... They actively secrete bone matrix
nonspecific excessive activation of immune system via polyclonal T cell activation caused by cytokine release
tRNAs catalyze formation of peptide bonds to create a chain of amino acids for the primary sequence of the proteins
way to prevent superantigen synthesis
binding "a specific complementary nucleic acid sequence" to mRNA would prevent translation, at least for the time being, by keeping mRNA bound to it
For the retrovirus to reproduce itself in host cells, its RNA must be converted to DNA, which requires the enzyme reverse transcriptase.
Bacterium v.s. viruses replication
Viruses = reproduce by replicating within host cell;
bacteria = repoduce by binary fission
Both bacteria and viruses have rigid outer covering, lack a nuclear membrane, and contain both RNA/proteins
Ectoderm (NS inc eye and spinal cord & epidermis), Mesoderm (blood/connective tissue/organs like kidney/heart/gonads), Endoderm (digestive organs and other related like liver, and respiratory)
Hardy Weinberg Equilibrium equations
p+q = 1
p^2 + 2pq + q^2 = 1
Myosin binds to actin and will remain bound until phosphorylated by ATP
(ATP is not specific to actin)
synthesis of antibody proteins (translated) by ribosomes attached to te rough endoplasmic reticulum
modifies proteins that were previously synthesized in the RER and exports them
Codominant v.s. Complete Dominance v.s. Incomplete Dominance
codominant = 2 dominant allelles are simutaneously expressed
complete dominance = dominant allele maks recessive allele
incomplete dominance = intermediate phenotype between 2 homozygous genotypes
monosynaptic stretch reflex (sensory neuron activation -> motor neuron in spinal cord)
Calculate the number of different possible gametes that can be formed by diploid organisms asa result of independent assortment of chromosomes during meiosis
2^n where n is the haploid number of chromosomes
Penetrance v.s. Expressivity
Penetrance = proportion of population with genotype that expresses the phenotype (full -> nonpenetrance of alleles)
Expressivity = different manifestations (phenotype) of the same genotype cross the population (constant or variable)
Law of Segregation
2 alleles separate in anaphase I (gametes carry only one allele)
Law of Independent Assortment
Inheritance of genes is independent (one does not affect another) because of recombination in meiosis I
Produced by liver
Stored in gall bladder
Secreted into small intestine
Functions as an emulsifier to facilitate fat digestion
Central Dogma in Eukaryotes
Transcription of DNA into RNA occurs in the nucleus. The RNA is then transported to the cytoplasm where ribosomes translate it into proteins.
forms cleavage furrow during cytokinesis (actin filaments contract to make the ring smaller which pinches off the connection between daughter cells)
organised into mitotic spindles by centrioles in the centrosome and attaches to chromosomes via kinetochores to pull apart sister chromatids; & forms 9+2 structure in motile eukaryotic organelles (cilia/flagella)
centrioles v.s. flagella structure
centrioles = 9 triplets of microtubules around a hollow center; flagella = 8 coublets on the outside with 2 microtubules on the inside
If chromosomal duplication before tetrad formation occurred twice during spermatogenesis, while the other steps of meiosis proceeded normally, what would result from a single spermatocyte?
Four sperm would be produced. Because replication occurred twice instead of once prior to tetrad formation, each sperm would have twice the normal amount of DNA. As a result, four diploid sperm would be produced instead of four haploid sperm.
Rise in serum Albumin
Albumin causes fluid influx to blood, so it would increase the flow of interstitial fluid into the bloodstream and result in an increase in blood pressure
Hair "stands on end"
this traps air within the layer of hair (insulating effect that prevents heat loss to environment)
Where does fertilization most commonly take place?
at the fallopian tube
Pathway of sperm
Seminiferous Tubules in testes -> Stored in epididymis -> Vas Deferens -> Ejaculatory duct -> Urethra
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