Upgrade to remove ads
BIO 1A FINAL
Terms in this set (188)
What is the weakest type of bio interactions
Van Der Waals interactions between hydrophobic AA residues
True or False: Macromolecules with same monomers linked by covalent bonds must have similar properties
Amount of H bonds between Cytosine and Guanine
True or False: Ribosomal subunits are assembled in the nucleolus and exported into the cytosol for function
How are lytic enzymes in the lysosome prevented from acting in cytosol?
They are contained by a single phospholipid membrane and operate at a lower pH
True or False: Chloroplasts translate nuclear encoded RNA
How are secretory proteins targeted for synthesis by ER bound ribosomes?
Ribo-mRNA complexes bind to ER when specific signal peptides are translated
True or False: Microtubules are the smallest component of cytoskeletal structure
For Na+/K+ ATPase, how would recovery rate be affected if lowered ambient temperature?
Recovery time would increase as membrane fluidity increased
How does voltage gated K+ channels distinguish between K+ and Na+?
Anhydrous K+ ions coordinate better with carbonyl oxygens in selectivity filter
Enzyme Z is competitively inhibited by ligand X. Would increasing X increase the amount of products formed?
Glu/ Na+ symporter is a transposon protein responsible for intaking Na+ and Glu. When is this a thermodynamically unfavorable rxn?
When the concentration gradient of Na+ is greater the concentration gradient of Glu
What is released when a phosphodiester bond forms between nucleotides during the synthesis of nucleic acids?
An enzyme is relatively high binding affinity for a substrate must have a:
What is the purpose of cytosolic formation of pyruvate?
to regenerate NAD+ from NADH
What would allosterically inhibit the rate of phosphofructokinase?
According to the Endosymbiotic Theory, in which compartment of prokaryotes would the pH be lower due to ETC?
In the space between the plasma membrane and cell wall
P680 is oxidized by ___________ and reduced by ____________
primary e- acceptor, water
True of False: The excited electron in the reaction center of Chlorophyll can reduce adjacent photopigments
Where is the highest concentration of phosphatase in the Calvin Benson Cycle?
What is the difference between C4 and C3?
Evolutionary Innovation: reduces photorespiration and conserves water
If a compound prevents microtubule assembly and if histones are fluorescently tagged, what would you observe?
Chromosomes condense but don't migrate to equator of cell
What would happen if microtubules disassembled at the poles?
Only the microtubule segments between the poles and bleached marks would shorten.
Human cell at the start/end of meiosis 1
Start: 2N 4C
End: 1N 2C
Human cell at start/end of meiosis 2
Start: 1N 2C
End: 1N 1C
F1: normal female x wild type male
F2: Females: all normal; males: 400, 400, 100, 100
What initiates the replication of E. Coli genome?
Primase making the 1st phosphodiester linkage between 2 ribonucleotide triphosphates
Where do two ribonucleotides bond?
first oxygen atom and 3rd phosphorus atom (l-->r)
What does the binding site of aminoacyl tRNA synthase bind to? What is this based on?
only one amino acid based on shape and charge distribution and ATP
When plants have inducer (IPTG) and Glucose, white colonies will be produced by: wildtype bacteria, I- bacteria, O-bacteria, or CAP-bacteria?
all of the above
How does a DNA glycosylase repair oxidation of guanine to 8- oxoguanine?
By removing the 8 oxoguanine
What begins/ends an amino acid sequence?
What does the tRNA in the A site have in the beginning of a peptide bond formation?
polypeptide with 4 amino acids
How is it possible to get organic specific and cell layer specific patterns of transcription in multicellular organisms?
The binding sites of many regulatory transcription factors can be distant from the promoter and still regulate its expression
How do miRNAs guide RISC complex to cleave or prevent translation of specific mRNAs?
miRNAs in RISC complex base pair with mRNA of their target
What is not necessary for DNA transposons to move in the genome autonomously?
A reverse transcriptase gene
What are colorful patterns in flowers due to?
excision of DNA transposons from a pigment biosynthetic gene
How do E. Coli bacteria protect themselves from bacteriophages (with DNA genomes)?
By digesting (hydrolyzing phosphodiester bonds) the bacteriophage DNA genome with restriction endonuclease
How do primers work in PCR?
Since DNA synthesis is always from 5' to 3' , the 3' ends of a PCR primer set point towards each other, when they are annealed to their template strand, and the primers anneal on opposite strands of the PCR template.
What are the three processes that occur during genetic recombination?
Transformation, Transduction, and Conjugation
Person to person variation in the coding sequence of the gene encoding taste receptor TAS2R38 leads to differences in bitter taste sensitivity. What is the most likely reason for different sensitivity to bitter taste?
Receptor variants bind with different affinity to bitter taste molecules, leading to differences in downstream
You have an advanced fluorescence microscope available to you as well as a human cell line expressing a fluorescently-tagged versions of a GPCR. When you look under the microscope, where do you expect to see these fluorescent proteins?
the plasma membrane
When referring to the process of development, what is the distinction between differentiation and determination?
Differentiation refers to cell structure and function becoming more specialized; determination refers to cell fates becoming more limited
Researchers investigating the differentiation of mouse embryonic stem cells into endothelial cells that line blood vessels and arteries have found that activation of one transcription factor leads to the further activation of other transcription factors and to the enhanced production of secreted signaling molecules. What is the most reasonable conclusion that these researchers can reach from their studies?
Differentiation involves changes in gene expression and the up regulation of secreted signaling molecules
Both the BOSS signaling protein and the Sevenless RTK are transmembrane proteins, with BOSS being located in the plasma membrane of the R8 cell, and Sevenless being located in the plasma membrane of the adjacent R7 cell. What signaling scheme does this represent?
What is the correct sequence of events that occurs during Sevenless activation by BOSS?
Ligand binding -->receptor dimerization -->tyrosine phosphorylation -->relay protein activation
In 2006, Nobel laureate Shinya Yamanaka reported that differentiated adult cells can be de -differentiated to become induced to become pluripotent stem (iPS) cells. To make this conversion, what was done to the differentiated cells?
four specific transcription factors were expressed by viral transduction
Embryologists have found via experiments that
transplantation of the optic vesicle (presumptive retina)
of the frog Xenopus laevis into an ectopic location (i.e., in a different place from where it normally forms) underneath the head ectoderm will cause the formation of eye lens tissue in that location. Why?
the optic vesicle produces an inducer to change the fate of neighboring cells
What best represents a difference in the functions of the endocrine and nervous systems?
The nervous system produces signals that are transmitted more quickly than those produced by the endocrine system
Where is the osmolarity of the kidney filtrate the highest?
at the bottom of the loop of Henle
Which of the following is NOT a part of the endocrine system: insulin, pituitary gland, gastric glands, epinephrine?
Water soluble hormones _________________, whereas lipid soluble hormones __________________
have transmembrane protein receptors; have receptors in the cytoplasm or nucleus
What characteristic do steroid and peptide hormones typically have in common?
their requirement for travel through the bloodstream
What is true of melatonin production during the 24 hour cycle of the day?
its levels peak in the evening when it's dark out
You learned in lecture and in an NPR radio clip that size variations in dogs can be caused by differences in insulin -like growth factor IGF1. What is everything you know about IGFs?
-they can act as paracrine signaling molecules
-they activate RTKs
-they stimulate a phosphorylation cascade involving MAP kinases
-they lead to changes in patterns of transcription
The protein MyD88 plays an important role in the signal transduction pathway downstream of Toll-like receptor (TLR) activation. What is the phenotype of mice missing the gene encoding MyD88?
they could not mount normal innate or adaptive responses
What is the concept behind the immunotherapy breakthrough pioneered by the work of Dr. James Allison, formerly of UC Berkeley, who was awarded the Nobel prize in 2018?
checkpoint inhibitors stimulate the killing of tumor cells by cytotoxic T cells
Cyanide poisoning (i.e. exposure to the toxic chemical forms of cyanide) leads to many symptoms, including loss of consciousness (i.e. your brain stops working) and cardiac arrest (i.e. your heart stops beating). Cyanide decreases greatly the production of ATP. This will greatly inhibit the action of the Na+/K+ pump in neurons and cardiac muscle cells. What is the expected consequence of cyanide on the membrane potential of these cells.
the resting membrane potential would go to 0 mV
The correct sequence of sensory processing is _____.
stimulus → transduction into graded potential → transmission → perception
Voltage-gated sodium channels are inactivated by the inactivation loop and the membrane's permeability to sodium ions is decreased when ______________
the AP hyperpolarizes
An opsin-based optogenetic tool was recently developed that is a gated K+ channel engineered by fusing the plant LOV2-Jα photosensory module to the small viral K+ channel Kcv.
Shining light and the resultant opening of K+ channels would be expected to ________.
hyperpolarize the cell
Phototransduction in rod and cone cells is initiated by what?
Activation of a G-protein coupled receptor
Of the various chemical bonds in biology, what is the strongest one?
The unique functional component of the amino acid cysteine is called
the sulfhydryl group
Enzyme cofactors could be
-iron -sulfur centers
Cholesterol is more likely to incorporate into membrane lipid bilayers when the latter
contain diglycerides with saturated fatty acids
Amylose is a polymer compound found in
eukaryotic cell chloroplasts
Phosphorylation of substrate is widespread in nature and it signifies that cells
Add high-energy phosphate bonds to substrate to enable further processing
Compared to the energy released by ATP hydrolysis to ADP and Pi
the energy released by NADH oxidation to NAD+ is
In C4 plants, carbon fixation takes place in the _____ using _______ and then the product is transferred to
the _____ where it enters the Calvin cycle.
Mesophyll cells, PEP carboxylase, bundle-sheath cell
The charge-separation reaction in photosynthesis uses the energy of absorbed sunlight to move an electron
The chemiosmotic hypothesis postulates
Delta pH across the bioenergetic membrane drives the ATP synthase activity
What distinguishes meiosis from mitosis
-separation of homologous chromosomes into distinct cells
-failure to synthesize DNA between successive cell divisions
If separated by 50 or more centimorgans, then what could be true?
-genetically unlinked OR
-physically linked and separated by 50 or more
Energy for phosphodiester bond formation by E. coli DNA polymerase III is provided by cleavage of
pyrophosphate from deoxynucleotide triphosphates (dXT)
What atom in the tRNA will make a covalent bond with an amino acid?
the oxygen atom in the ribonucleotide
What dipeptides can ribosome synthesize?
-dipeptide begins with NH2, is linked with NH, and ends in COH
-all molecular rules apply
Transcription and translation of a new mutation in the E. coli
lac repressor gene produces a stable repressor that is unable to bind IPTG. However, the mutant repressor can still tightly bind to the lac operon operator (O). The mutant E. coli are grown in media that has glycerol as an energy and carbon source. The media has no glucose. The lac operon in the mutant E. coli will be
not transcribed in the presence or absence of IPTG
me synthesizes RNA that is complementary to a DNA template?
The cell prevents movement of many transposons
preventing their transcription
An E. coli DNA glycosylase repairs DNA by
in wild -type E. coli, the amino acid tryptophan (trp) is
not synthesized when tryptophan is present in the
environment. This is because the trp repressor, when bound to tryptophan,
binds to the operator (O site) on the trp operon.
Transcription of a miRNA gene produce
miRNA biogenesis. Transcription of a miRNA gene produces a large pri-miRNA, which is spliced to produce a smaller pre-miRNA, which is exported from the nucleus to the cytoplasm, and spliced again to produce miRNA.
Suppose a bacterial strain has a wild-type EcoR1 restriction endonuclease gene and a corresponding wild -type EcoR1 DNA methyltransferase gene. What will happen to an individual bacterium that suffers a loss-of - function mutation in its EcoR1 restriction endonuclease gene?
it will not be able to digest an infecting bacteriophage
that has EcoR1
An enzyme used to distinguish between open versus closed chromatin
True or false: Alterations in cell communication pathways
are rarely implicated disease
Mutations in a gene encoding what protein is most likely to lead to
an increased taste sensitivity to bitter
compounds, but not other taste molecules
The bitter compound taste receptor GPCR
What is a model organism?
An organism selected for study as a representative
for a larger group of species
What is a reasonable
way to use stem cells to generate insulin-producing pancreatic beta cells to treat diabetes?
Use various growth factors to differentiate
embryonic stem cells into pancreatic beta cells that
What approach is the primary importance in determining the regions of the embryo that act in pattern formation?
What approach is the primary importance in identifying the genes and corresponding proteins that function in pattern formation?
genetics in model organisms
Under what circumstances are negative feedback loops used in biological systems:
To maintain homeostasis
Under what circumstances are positive feedback loops used in biological systems:
To promote rapid change
The production of pepsin is an example of a
Positive feedback loop
What would be the most effective way of assessing microbial diversity (ie. how many different species) inhabit the gut:
isolate feces, extract and sequence DNA, look for microbial genes that define each species
what do gap junctions do?
allow electrical impulses to spread between cardiac muscle cells
The normal contraction of specialized atrial cells results
from the activity of the _______, and the simultaneous
contraction of the left and right atria is due to the
autorhythmic pacemaker cells; gap junctions
What is NOT an adaptation that would increase O2 exchange in the lung
Increase the distance over which exchange occurs
The two words in the phrase "countercurrent multiplier"
refer to the following: countercurrent refers to the______, and multiplier refers to the _________
flow of filtrate in opposite directions; establishment
of salt gradient that enables osmosis and reabsorption of water
Animals that can produce exceptionally concentrated urine should be expected to have nephrons with longer
loops of Henle
Drinking alcohol causes increased urination. Explain
Alcohol suppresses ADH
What property could be conferred by signaling cascades comprised of multiple signaling proteins?
-Signal amplification (strengthening the signal)
-Signal distribution (transmitting the signal to
various intracellular pathways & locations)
-Signal integration (enabling responses to multiple
How could you test whether TLRs function in the innate immune response to pathogens?
-Test whether a mutation in the Toll gene in the
fruit fly causes susceptibility to fungal infections.
-Test whether a mutation in the tlr4 gene in mice causes susceptibility to bacterial infections.
What are B cells activated by and what do they become?
B cells activated by pathogen-specific antigens become plasma & memory cells
What do cytotoxic t cells do?
Cytotoxic T cells kill infected and
For Na+, Co=150mM and Ci=15mM. What is the equilibrium membrane potential for Na+?
The resting potential of a neuron is about -70 mV. Therefore, the resting potential is dominated by what?
Na+/K+pumps AND K+leak channels
The action potential is mostly due to ion movements through
voltage-gated Na+and K+channels
How do neurons communicate via synapses?
2.Influx of Ca2+
3.Synaptic vesicle fusion and neuro-transmitter release
4.Neuro-transmitter binds and activates ligand-gated channels on postsynaptic cell
What are sensory neurons?
cells that have specializations that convert stimulus energy to changes in membrane potential
Classify and describe each sensory receptor
Photoreceptors --photons (vision)
Chemoreceptors -taste and smell
Mechanoreceptors -vibration (hearing & somatosensation)
Cholera toxin, produced by the bacterial pathogen Vibrio cholerae, causes diarrhea by modifying a heterotrimeric G-protein and preventing its ability to hydrolyze GTP to GDP and Pi. What would be the effect of cholera toxin on G-protein activity?
It would lead to continual activation of the G-protein
What would be affected by treating cells with an inhibitor that prevents cAMP activation of protein kinase A?
Increased cardiac contractility in response to norepinephrine
What is FALSE regarding the process of signal transduction via GPCR, G-protein and phospholipase C?
The activated G protein migrates into the nucleus to activate gene transcription
You have used affinity chromatography to find a protein that binds tightly and specifically to the mineralocorticoid hormone aldosterone. What is the most likely function of this protein?
What is the sequence of developmental events that allow
s a single cell to give rise to a multicellular organism.
Division --> differentiation --> pattern formation --> morphogenesis
Epidermal growth factor (EGF) is a paracrine signaling molecule able to influence multiple cell fate determinations during vulva development. How is EGF able to influence multiple cell fates (fate A and fate B) during vulva pattern formation?
EGF acts in a concentration dependent manner: high EGF results in cell fate A, low EGF results in cell fate B
Hox genes encode proteins that ar
Homeodomain-containing transcription factors
What observation by Rita Levy Montalcini led to the discovery of the activity of nerve growth factor (NGF)?
NGF stimulates the outgrowth of neurons from chick sensory ganglia
Three key principles of physiology are:
Form, function, regulation
Which of these is NOT one of the four major categories of tissue: Muscle, Epithelial, Connective, Endodermal, Nervous
What would disruption of countercurrent flow have the most negative impact on?
Water reabsorption in the nephron; minimizing heat loss in body extremities
What is the major cause of stomach ulcers?
Helicobacter pylori infection
_________ blood enters the left atrium and ________ blood enters the right atrium
What happens during atrial and ventricular diastole?
During atrial and ventricular diastole blood flows into the atria and ventricles
You discover a new species of toad on Berkeley campus. After researching it, you conclude that it has a higher rate of gas
diffusion in its alveoli compared to closely related toads on campus. What could best explain this?
The new species has a higher total surface area of its alveoli
What explains greater O2 delivery to tissues when you exercise?
The O2 saturation of hemoglobin decreases at low pH during exercise
The part of the kidney's anatomy that is most directly involved in blood filtration is the:
Can hydrophobic hormones bind to cell surface receptors to initiate signaling?
How was the gene encoding the circadian rhythm regulatory protein "period" discovered?
Genetics in fruit flies
Toll-like receptors (TLRs) would be LEAST likely to recognize which of the following: Double-stranded RNA produced by many viruses; Liposaccharide produced by Gram-negative bacteria; Flagellin produced by Gram-positive and Gram-negative bacteria; The hemagglutinin protein produced by the influenza virus; Peptidoglycan, a cell wall component of bacteria
The hemagglutinin protein produced by the influenza virus
The following cells play a role in the adaptive immune system EXCEPT: Plasma cells, B cells, Helper T cells, Cytotoxic T cells, Neutrophils
A loud noise startles you while you are working quietly on your worksheet, your heart rate speeds up, your pupils dilate, and you feel a rush of adrenaline. What branch(es) of your nervous system is responsible for this response?
Peripheral nervous system, Autonomic nervous system, Sympathetic nervous system
Norepinephrine binds to what type of receptor?
G-protein coupled receptor
The amount of neurotransmitter released from a presynaptic cell is a function of:
The frequency of arriving action potentials in the presynaptic neuron
How are the sympathetic and parasympathetic nervous systems similar?
Efferents emerge from the same region of the spinal cord
A hydrogen bond in biological systems forms when
a hydrogen atom is covalently bonded to one electronegative atom which is attracted to another electronegative atom
What does a prokaryotic cell not have?
nucleus, endoplasmic reticulum, mitochondria
Phosphorylation of substrate is widespread in nature and it signifies that cells
add high-energy phosphate bonds to substrate to enable further processing
Optimal pH for pepsin (stomach enzyme) is
At the end of glycolysis
Substrate phosphorylation makes ATP
Chlorophyll molecules are
closed tetrapyrroles AND contain non- pyrrole fifth ring
DNA sequencing reveals that two identical genes, APO1 and APO2, are next to each other on chromosome 4 of the human genome. A likely explanation is that
Very recently, unequal recombination occurred between repeated sequences that flanked the ancestral APO gene on chromosome 4.
Many of the color patterns in flowers are caused by transposons. The colored portions of the petal are likely caused by a transposon that
exited a pigment biosynthesis gene.
Which drug would most likely be the best candidate to specifically inhibit progression of the AIDS virus? A specific inhibitor of
Splicing is initiated by nucleophilic attack of a phosphodiester linkage at the 5'-end of the intron by an electron pair from a
2'-OH of a ribonucleotide within the intron.
The adult and fetal b-hemoglobin genes
encode proteins with different affinities for oxygen.
Dideoxynucleotide triphosphates are used in DNA sequencing because they
lack a 3'-OH that is required for phosphodiester linkage formation.
Reverse transcriptase is able to synthesize a complementary copy of
DNA using a RNA template AND DNA using a DNA template
snRNAs are small single-stranded RNAs that are present in the
miRNAs are small single-stranded RNAs that are present in the
RNA molecules play a significant role in the movement of electrons in which of the following reactions?
-peptide bond formation.
How does cAMP promote CAP protein binding the DNA just upstream of the RNA polymerase binding site at the lac operon?
cAMP non-covalently binds to the CAP protein, causing CAP to change its shape so that its amino acids have a complementary shape and charge distribution to its DNA binding site.
The b-hemoglobin gene is not transcribed in the fetus, but is transcribed shortly after birth. The HEM gene encodes a negative regulatory transcription factor that controls b-hemoglobin gene transcription. A 1-base pair deletion mutation in the first exon of the HEM gene would be expected to produce which pattern of b-hemoglobin gene transcription?
Transcription in fetus and after birth are both ON
Which type of RNA is responsible for degrading its target mRNAs?
Denote which of the following facilitate primary, secondary, tertiary, and quaternary protein structure:
-Interactions between two regions of a protein backbone
-Association of two protein subunits to form a larger complex
-The sequence of amino acids in a polypeptide chain
-Interactions between amino acid side chains
What fatty acid can not be generated with hydrolysis of a lipid?
Cis-unsaturated fatty acid
You would like to study the intramembranal structures present in a human cell. What technique discussed in class would you use?
Transmission electron microscopy
True or false: The addition of phosphate on a substrate by a kinase does not always activate the molecule, but the removal of phosphate on a substrate by a phosphate will always inactivate a molecule.
False. The addition of phosphate by kinase and the removal of phosphate by phosphatase may result in the activation or deactivation of a molecule.
True or False: In general, condensation reactions are endergonic and hydrolysis reactions are exergonic.
The three types of cellular work are powered by the ____________ of ATP. This conversion of ATP to ___________ allows for ________________ of another molecule. In other words, the energy from catabolism of ATP, which is _______________, is coupled to the energy needed for cellular
work, which is _____________, so that net ΔG is ______________.
What is the overall breakdown of glucose in the presence of O2 in the cell? Is this reaction endergonic or exergonic? Which molecule is being oxidized and reduced?
-C6H12O6 + 6O2→ 6CO2 + 6H2O + 32ATP
-This reaction is exergonic (releases energy) and catabolic (breakdown of glucose)
-Glucose is being oxidized into CO2; O2 is being reduced into H2O
What is the Warburg effect? In which types of tissue does it occur?
The Warburg effect occurs in cancerous and highly proliferative tissues, and is an unexplained phenomena in which cells prefer glycolysis over oxidative phosphorylation. This preference makes cancer cells
Fill in the blank. For every 2 electrons in the electron transport chain, _________ protons are pumped, and __________ molecule(s) of ATP are made.
What are the fates of an excited electron?
Heat, fluorescence, reduction of reaction center electron carrier
What is prometaphase?
Nuclear envelope breaks down, chromosome pairs attach to spindle microtubules via kinetochores
What are the four processes that generate variation in progeny?
Mutation, Random Fertilization, Independent Assortment of Homologous Chromosomes,
Recombination between homologous chromosomes
What do Helicase, DNA polymerase 1 and 3, primase, and ligase DO?
-Helicase separates template DNA strands
- DNA polymerase III adds nucleotides to the growing DNA strand
-DNA polymerase I replaces RNA primer with DNA
-primase synthesizes RNA primer
-ligase joins Okazaki fragments.
Why are prokaryotic promoter regions typically rich in TATA sequences?
Only two hydrogen bonds form between the T, A base pairs relative to the three hydrogen bonds between G
and Cs. These weaker relative interactions allow TATA regions to be easily unwound for eventual binding of
What do operons DO?
Operons coordinate production of functionally related proteins
Which of the following conditions results in the expression of the
lac operon in a wild-type E. coli cell?
Lactose is present, Glucose is not present
You have discovered an E. coli mutant which is colorless when plated on media with X-gal both WITH and WITHOUT the addition IPTG. Assuming the mutation is not in the gene for β-galactosidase,
does this indicate a mutation in a positive or negative regulator
of the lac operon? Explain.
This would be consistent with a mutation in a positive regulator. It suggests expression of the lac operon is constitutively off but is activated in the presence of IPTG. If the mutation were in a negative regulator, colonies would be blue in both conditions.
Loss-of-function mutations in negative regulators cause constitutive activity (always on). Loss-of-function mutations in positive regulators cause non-inducible activity (always off).
For the following, indicate if expression of the
lac operon would be inappropriately increased, inappropriately decreased, or unaffected. Explain your reasoning.
-Mutation in the operator
-Mutation in the cAMP binding site of CAP
-Mutation in the promoter
-Mutation in the CAP binding site
-Mutation in the repressor
-Mutation in the lactose-binding site of the repressor
-Inappropriately increased (repressor cannot bind even in absence of lactose)
-Inappropriately decreased (CAP is not active even when glucose is low)
-Inappropriately decreased (RNA polymerase cannot bind)
-Inappropriately decreased (CAP cannot bind even when cAMP is bound)
-Inappropriately increased (repressor cannot bind even in absence of lactose)
-Inappropriately decreased (repressor cannot bind lactose so does not change
shape and remains bound even when lactose is present)
What is a repressor?
A repressor is a protein which binds a DNA sequence called an operator, inhibiting the expression of one or more genes
What molecule interacts with the spliceosome to regulate
RNA- binding proteins
Label each of the following descriptions as characteristic of bacteriophages, retroviruses, both, or neither.
-Binds to surface receptor proteins on target cell:
-Can be composed of RNA or DNA:
-Can replicate outside host cell under some circumstances:
-Requires integrase protein to replicate:
-Synthesizes DNA from an RNA template:
-Hijacks host cell's molecular machinery to replicate:
-Lyses host cell to exit:
Compare and contrast retrotransposons with retroviruses.
Both retroviruses and retrotransposons have protease and reverse-transcriptase/integrase genes. But retroviruses have a capsid gene that allows them to encapsulate their RNA and proteins to exit the cell and infect other cells. Retrotransposons are missing a capsid gene, so they can only make copies of themselves within the host cell's genome.
Electroporation is a technique that uses a brief electrical pulse to increase the permeability of the cell membrane, allowing exogenous DNA to be taken into the cell. During electroporation of bacterial cells, only about 1 in 10,000 cells acquire a plasmid molecule. How can we efficiently select only the cells that have taken up a plasmid to use in the rest of the protocol (amplification of bacterial colonies and extraction of plasmid DNA)?
Design a plasmid with an antibiotic resistance gene such as ampR. Grow the transformed population on a plate with antibiotics. Only the bacteria that acquired the plasmid will be antibiotic-resistant, so all of the other cells will die.
If the expression of all copies of a particular Hox gene encoding for a human head were knocked out, what would the expected result be regarding the identity of the affected region?
-The head would not form normally
Match each macromolecule to the component(s) of the digestive system in which digestion and nutrient absorption take place:
-mouth and small intestine
-stomach and small intestine
When glucose levels are low, the (alpha/beta) cells of the pancreas secrete (insulin/glucagon), causing the (release/uptake) of glucose into the blood. When glucose levels are high, the (alpha/beta) cells of the pancreas secrete (insulin/glucagon), causing the (release/uptake) of glucose from the blood. Medical disorders in which the production or function of insulin is disrupted are known as diabetes.
Imagine you are a water molecule that has just been (secreted/filtrated) into the renal tubule. As you go down the length of the renal tubule, you go from the (renal cortex/medulla) to the (renal cortex/medulla.) In other words, as you go down the descending loop of Henle, you see that the osmolarity of the surrounding tissues is (increasing/decreasing.) Following the process of (diffusion/osmosis/active transport,) you are removed from the filtrate, you leave the renal tubule and enter the blood supply (meaning you are reabsorbed).
What is the difference between osmolarity and tonicity?
-Osmolarity is concentration expressed in units of solute/volume. It can be measured on
a machine called an osmometer, and it has units, usually osmoles or milliosmoles per liter
-Tonicity is a behavioral term. It describes what a solution would do to a cell's volume at
equilibrium if the cell was placed in the solution.
What are the steps of the signaling pathway of ADH?
1.Binding of vasopressin to the GPCR in the basolateral membrane activates the G-protein
2.Alpha portion of G-protein activates adenylate cyclase (AC)
3.AC increases intracellular cAMP levels, the secondary messenger
4.High cAMP levels activates protein kinase A (PKA), phosphorylating enzyme that initiates an intracellular phosphorylation cascade
5.Ultimately, intracellular aquaporin-2 (AQP2) storage vesicles are phosphorylated, which promotes their movement and insertion into the apical membrane, rendering this membrane water permeable.
Transposons are expressed at _________levels because they have ________ levels of methylation?
What act as the "switch" to turn G-proteins on?
GDP exits the inactive G-protein, allowing GTP to enter
An egg cell is an example of which kind of stem cell?
Vulva cell fate determination is an example of what?
YOU MIGHT ALSO LIKE...
Test Four Chapter 16
Bio exam 4
Test 2: practice quizzes & top hats
Chapter 11 Cell Communication
OTHER SETS BY THIS CREATOR
NUSCTX 10S FINAL (L15-L25)
NUSCTX 10S Midterm #2
NUSCTX 10S Midterm #1
PB HLTH 162A