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1st Theme that connects the concepts of biology
New Properties Emerge at Each Level in the biological Hierarchy
3rd Theme that connects the concepts of biology
Structure and Function are correlated at all levels of biological organization
4th Theme that connects the concepts of biology
Cells are an organisms basic units of structure and function
7th theme that connects the concepts of biology?
Evolution accounts for the unity and diversity of life
What is the general concept of biology that all themes are connected to
Scientists use two forms of inquiry in their study of nature
Scientists use two forms of inquiry in their study of nature
Theme 1: New properties emerge at each level in the biological heirarchy (4 concepts)
-Levels of organization
Theme 2: Organisms interact with their environments (2 concepts)
What is positive feedback?
means that as more of a product accumulates, the process that creates it speeds up and more of the product is produced
What is negative feedback?
means that as more of a product accumulates, the process that creates it slows & less of the product is produced
Theme 7: Evolution accounts for the unity and diversity of live (3 concepts)
-Organizations of life
-Three domains of life
-Charles Darwin & the theory of natural selection
Levels of biological organization
6 organs and organ systems
What are emergent properties?
Properties that result from the arrangement and interaction of parts within a system
What does systems biology do?
constructs models for the dynamic behavior of whole biological systems
T/F Every organism interacts with its environment and other organisms, not including nonliving facts
FALSE (does include nonliving factors)
Both organisms and their environments are affected by the interactions between them. This is considered the exchange of..
matter & energy
Ecosystem Dynamics' 2 major processes:
1. cycling of nutrients, in which materials acquired by plants eventually return to the soil
2. The flow of energy, from sunlight to producers and consumers
Energy can be stored how..
in many different forms such as light, chemical, kinetic, potential, and thermal
The energy exchange between and organism and its environment often involves...
T/F Structure and function of living organisms are closely related
(example: a leaf is thin & flat, maximizing the capture of light by chloroplasts)
The ____ is the lowest level of organization that can perform all activities required for life.
What did Darwin observe?
-Individuals in population have traits that vary
-Many of these traits are heritable (passed on)
-More offspring are produced than survive
-Competition is inevitable
-Species generally suit their environment
Darwin inferred from his observations that:
-Individuals that are best suited to their environment are more likely to survive & reproduce
-Over time, more individuals in a population will have the advantageous traits
Evolutionary relationships are often illustrated with what kind of diagrams that show ancestors and their descendants?
What's the difference between qualitative and quantitative data?
qualitative - descriptions rather than measurements
quantitative - recorded measurements
deriving general principles from particular facts or instances (Sun always rises in the east, objects fall to the ground).
Hypothetical explanations which are proposed from observations that lead us to ask questions
capable of being tested (verified or falsified) by experiment or observation; capable of being disproved
Deductive Reasoning does what?
uses general premises to make specific predictions (if organisms are made of cells, and humans are organisms, then humans are composed of cells)
1. Observations/Define problem
2. Collect information
3. Form Hypothesis
4. Test hypothesis/Experiment
5. Make conclusions based on testing
6. Report results
What is a controlled experiment?
One that is designed to compare an experimental group with a control group
Controlled experiments are ones that are designed to compare an experimental group with a....
Scientific Theories are characterized by these 3 characteristics..
-Broader in scope than a hypothesis
-Supported by a large body of evidence in comparison to a hypothesis
3 forms of Matter that build off of eachother
2. Atoms (smallest unit of element)
3. Isotopes (two atoms of an element have different number of neutrons)
Subatomic particles of an atom
-Protons (positive charge)
-Electrons (negative charge)
Hydrogen bonds form when...
a hydrogen atom that is covalently bonded to an electronegative atom is also attracted to another electronegative atom
Van der Waals interactions occur ONLY when...
atoms and non-polar molecules are very close together, due to regions of slightly opposite charge
new properties that emerge with each step upward in the hierarchy of life, owing to the arrangement and interactions of parts as complexity increases
Lock and Key Theory (explain)
Deals with enzymes; there's always a unique way that something must fit, and it doesn't fit, it will not work
In chemical reactions, do all atoms of the reactants have to be accounted for?
Yes, balanced equations
Reversible reactions are what..
have to do with chemical reactions; proceed both ways
(3H2 + N2 <=> 2NH3)
When talking about the chemical equilibrium, the _______ remains the same, but the _____ goes forward and backward.
concentration remains the same; reaction goes forward and backward
A liquid at body temperature is good for two reasons
it can flow freely & it is excellent for transportation of solutes
Emergent properties of water:
1. Cohesive behavior
2. Ability to moderate temperature (never a rapid increase or decrease in temperature)
3. Expansion when frozen
4. Versatile solvent
Surface tension is what?
a force to pull liquid inward; or how difficult it is to break the surface of a liquid
All hydrogen bonds make almost a film... explain.
Hydrogen bonds form a film that is an invisible coat on the surface of water molecules
Water can absorb or release a large amount of heat with what kind of change in temperature?
Specific Heat (Definition)
Amount of heat that must be absorbed or lost for 1 gram of that substance to change its temperature by 1 degree C
Why does a pot get hot before the water even begins boiling?
Concept of specific heat.
Iron gets hotter because it has a lower specific heat than water
Why is specific heat so important?
Affects climate and oceans;
coast gets cooler in summer because water absorbs heat. coast gets warmer in winter, because water is giving off heat
As a liquid evaporates, its remaining surface cools, a process known as..
(in coffee, surface is cooler than bottom)
When you sweat, you release molecules that are hot first to cool you down. This is an example of
Evaporative cooling of water helps stabilize __________ in organisms and bodies of water.
Acids are any molecules that..
can donate hydrogen ions in aqueous solutions, have more hydrogen ions than pure water
Bases are any molcules that..
can accept hydrogen ions in aqueous solutions, has fewer hydrogen ions than pure water
What is a buffer?
Substances that minimize changes in pH that might occur when acids or bases are added.
Carbon is unparalleled in its ability to form what kind of molecules?
Large, complex and diverse molecules
The valences of what 4 atoms are the "building code" that governs the architecture of living molecules.
carbon, hydrogen, oxygen, and nitrogen
Compounds with the same molecular formula but different structures and properties are what..
Isomers that have the same covalent arrangements but differ in spatial arrangements.
All living things are made up of four classes of large biological molecules:
What is a polymer?
Long molecule consisting of many similar building blocks (monomers) in macromolecules
Occurs when two monomers bond together through the loss of a water molecule
condensation reaction or dehydration synthesis
Bonds between monomers are broken by addition of water molecules is & is the reverse of dehydration synthesis..
Macromolecules vary among cells of an organism, vary ____ within a species, and even ______ between species.
-Glucose most common
-Major fuel for cells
-Raw material for building molecules
Structure and function of a polysaccharide are determined by..
its sugar monomers and the positions of glycosidic linkages
Saturated fatty acids have the _______ number of hydrogen atoms possible and no ______ bonds.
maximum ; double
-half of dry mass cells
- many functions
-enzymes speed up chemical reactions
What gives proteins their unique functions?
how they are folded and coiled into a specific 3D structure
4 Levels of Protein Structure
1. Primary Structure
2. Secondary Structure
3. Tertiary Structure
4. Quaternary structure
Secondary structure of a protein: a coil is called a what? a folded structure is called a what?
coil - Alpha Helix
folded - Beta Pleated Sheet
proteins molecules that assist proper folding of other proteins (aka chaperone proteins)
Prokaryotic Cells Characteristics
-has plasma membrane
-has DNA but no nucleus
-No membrane bound organelles
Eukaryotic Cells Characteristics
-Single or multicellular
-has plasma membrane
-has DNA in nucleus
-has membrane bound organelles
Components of endomembrane system?
Golgi apparatus functions
Modifies products of the ER
Manufactures certain macromolecules
Sorts & Packages materials into transport vesicles
Ribosomes carry out protein synthesis in two locations..
-in cytosol (free ribosomes)
-on the outside of ER or the nuclear envelope (bound ribosomes)
Components of endomembrane system:
Sites of cellular respiration, a metabolic process that generates ATP is what organelle?
Mitochondria & Chloroplasts characteristics
-not part of endomembrane system
-have proteins made by free ribosomes
-contain their own DNA
Extracellular structures in plants and animals are..
Cell walls - plants
extracellular matrix - animals
List the 3 parts that a nucleotide consists of.
1. nitrogenous base
2. pentose sugar
3. phosphate group
Pentose sugar molecule consists of what
5'C bond from phosphate group right to sugar, CH₂, O, 3'C to the right of the sugar
Nitrogenous base is connected to what in a nucleic acid in terms of molecules?
Sugar is connected below the nitrogenous base
Difference in molecular structure between pyrimidines and purines.
Pyrimidines have one one octagon
Purines have two octagons, one being C₂N₂HCH
covalent bonds that link nucleotide polymers together when forming a polynucleotide
Phosphodiester bonds form between the ____ group on the ___ carbon of one nucleotide and the ____ group on the ___ carbon on the next.
Phosphodiester bonds form between the [-OH GROUP] on the [3'] carbon of one nucleotide and the [PHOSPHATE] group on the [5'] carbon on the next.
What are the backbones of a DNA double helix?
sides of the ladder.
run in opposite directions
(5' --> 3' & 3' --> 5')
In DNA double helix, the two backbones run in opposite 5' --> 3' directions from eachother. This arrangement is referred to as _________.
What nitrogenous bases always pair up together?
Adenine (A) with Thymine (T)
Guanine (G) with Cytosine (C)
There is one base that changes depending on whether DNA or RNA is being used. In DNA it is ________ & RNA it is ________.
Thymine (DNA) & Uracic (RNA)
Summarize DNA replication.
1. Parent molecule unwinds
2. Two new daughter strands are formed
3. Daughter DNA molecules are formed each consisting of one parental strand and one new strand.
Semiconservative Model of Replication
After replication, each daughter molecule will have one old strand ("conserved" from the parent molecule) and one newly made strand
More than a(n) _____ ____ and other ______ participate in DNA replication.
more than a dozen enzymes
When DNA replication begins at the origins of replications, what happens?
2 DNA strands are separated and form a replication "bubble"
(DNA Replication) Eukaryotic Chromosomes contain how many origins of replication?
100-1000s of origins of replication
Replication proceeds in _____ directions from each origin, until the _____ _____ is copied.
Replication proceeds in (BOTH) directions from each origin, until the (ENTIRE MOLECULE) is copied.
Single-Strand Binding Protein
Stabilizes and binds to single-stranded DNA until it can be used as a template
corrects "overwinding" ahead of replication forks by breaking, swiveling, and rejoining DNA strands
enzyme that catalyzes the successive addition of each new nucleotide to the growing chain
enzyme that starts an RNA chain from scratch and adds RNA nucleotides one at a time using the parental DNA as a template
The rate of elongation during DNA replication is about what per second in bacteria and what per second in human cells?
500 nucleotides per second (bacteria)
50 nucleotides per second (humans)
As each monomer of dATP joins the DNA strand, it loses ________ as a molecule of _______.
it loses (2 phosphate groups) as a molecule of (pyrophosphate)
Because DNA polymerases add nucleotides only to the free 3' end of a growing strand. Because of this, what happens?
New DNA strands can elongate only in the 5' to 3' direction
Along one template strand of DNA, the DNA polymerase synthesizes a ______ _______ continuously, moving toward the what?
Leading Strand which move toward the Replication fork
To elongate the lagging strand, DNA polymerase must work in what direction in relation to the replication fork.
away from the replication fork
The lagging strand in DNA Replication is synthesized is synthesized as a series of segments called what?
Single-Strand binding protein
Protein that binds to and stabilizes single-stranded DNA until it can be used as a template
Protein that relieves "overwinding" strain ahead of replication forks by breaking, swiveling, and rejoining DNA strands
Protein that synthesizes an RNA primer at the 5' end of leading strand and of each Okazaki fragment of the laggin strand
DNA pol III
Protein using parental DNA as a template which synthesizes new DNA strands by covalently adding nucleotides to the 3' end of a pre-existing DNA strand or RNA primer
DNA pol I
Protein that removes RNA nucleotides of primer from 5' end and replaces them with DNA nucleotides
Protein that joins 3' end of DNA that replaces primer to rest of leading strand and joins Okazaki fragments of lagging strand
The proteins that participate in DNA replication form a large complex called what?
DNA replication machine
Recent studies support a model in which DNA polymerase molecules do what?
Reel in parental DNA and force out newly made daughter DNA molecules
DNA polymerases _______ newly made DNA, doing what?
proofread newly made DNA, replacing any incorrect nucleotides
The cellular process that uses special enzymes to fix incorrectly paired nucleotides.
DNA can be damaged by what? Give examples.
examples: radioactive emissions, x-rays, UV light, and certain molecules in cigarette smoke, etc.
What happens in nucleotide excision repair?
a nuclease cuts out and replaces damaged stretches of DNA
An enzyme that cuts DNA or RNA, either removing one or a few bases or hydrolyzing the DNA or RNA completely into its component nucleotides.
Although telomeresDO NOT prevent the shortening of DNA molecules, they DO...
postpone the erosion of genes near the ends of DNA molecules
If chromosomes of germ cells became shorter in every cell cycle, what would happen?
essential genes would eventually be missing from the gametes they produce
The shortening of telomeres might protect cells from...
cancerous growth by limiting the number of cell divisions
There is evidence of telomerase activity in...
cancer cells, which may allow cancer cells to persist.
Chromosome organization in a bacterial chromosome..
circular DNA molecule associated with a small amount of protein
Chromosome organization in eukaryotic chromosomes..
Linear DNA molecules associated with a large amount of protein.
Interactions between nucleosomes cause the thin fiber to coil or fold into this thicker fiber.
the 30 nm fiber forms these loops which attach to a chromosome scaffold made of protiens - 300 nm fiber.
In prokaryotes, mRNA produced by transcription is what...
immediately translated without more processing
What is the concept that cells are governed by a cellular chain of command: DNA -> RNA -> Protein
The central dogma is the concept that cells are governed by a cellular chain of command which is what?
DNA -> RNA -> Protein
There are __ amino acids, but there are only ___ nucleotide bases in DNA.
20 amino acids
4 nucleotide bases in DNA
the normal version of the genetic code in which a sequence of three nucleotides codes for the synthesis of a specific amino acid
During what stage does the template strand provide a template for the sequence of nucleotides in the mRNA transcript.
During what stage does the mRNA base triplets or codons get read in the 5' to 3' direction
Each codon does what?
specifies the amino acid to be placed at the corresponding position along a polypeptide.
Each codon specifies the amino acid to be placed at the __________ position along a polypeptide.
Of the 64 triplets (codons), there are three that do what?
there are 3 codons that are "stop" signals to end translation
Why must codons be read in the correct reading frame?
in order for the specified polypeptide to be produced
The genetic code is nearly universal shared by the ______ ________ to the _____ _______.
shared by the simplest bacteria to the most complex animals
Genes can be transcribed and translated after what?
after being transplanted from one species to another
Example of expression of genes from different species..
-tobacco plant expressing firefly gene
-pig expressing a jellyfish gene
RNA polymerase catalyzes the synthesis of mRNA by doing 2 things..
1. pries the DNA strands apart
2. hooks together the RNA nucleotides
Three Stages of Transcription (RNA)
1. RNA Polymerase Binding & Initiation of Transcription
2. Elongation of the RNA Strand
3. Termination of Transcription
During Initiation stage of transcription of RNA, what first signals the initiation of RNA synthesis?
Transcription initiation complex
the completed assembly of transcription factors and RNA polymerase bound to the promoter.
The completed assembly of transcription factors and RNA polymerase bound to the promoter is called the..
Transcription initiation complex
During the elongation of the RNA strand, RNA polymerase moves along the DNA which does what?
untwists the double helix
During elongation of the RNA Strand, transcription progresses at what rate in eukaryotes?
40 nucleotides per second
Mechanisms of termination are or are not different in bacteria and eukaryotes?
Mechanisms of termination ARE different in bacteria and eukaryotes.
Describe how termination of transcription occurs in eukaryotes?
polymerase continues transcription after the pre-mRNA is split from the growing RNA chain; the polymerase eventually falls off the DNA
How do enzymes modify pre-mRNA before the genetic messages are sent to the cytoplasm?
1. Alteration of mRNA ends
2. Splitting of Genes and RNA Splicing
During the alteration of mRNA ends, each end of a pre-mRNA molecule is modified in what way?
the 5' end receives a modified nucleotide 5' cap
the 3' end gets a poly-A tail
Most eukaryotic genes and their RNA transcripts have what...
long noncoding stretches of nucleotides that lie between coding regions
Why are coding regions called exons?
Because they are eventually expressed which makes amino acid sequences.
removes introns and joins exons, creating an mRNA molecule with a continuous coding sequence
Some genes can encode more than one kind of polypeptide, depending on what..
depending on which segments are treated as exons during RNA splicing
Some genes can encode more than one kind of polypeptide, depending on which segments are treated as exons during RNA splicing. Such variations are called..
alternative RNA splicing
Because of alternative splicing, the number of different proteins an organism can produce is ____ than its number of genes.
Why aren't molecules of tRNA identical?
-Each carries a specific amino acid on one end
-Each has an anticodon on the other end
Accurate translation requires two steps..
1. Correct match between a tRNA and an Amino Acid
2. Correct match between the tRNA anticodon and mRNA codon
What enzyme is associated with the correct match between a tRNA and an amino acid
Wobble (flexible pairing at the third base of a codon) allows some tRNAs to..
bind to more than one codon
The initiation stage of translation in building a polypeptide brings together 3 things..
2. tRNA with first amino acid
3. Two ribosomal subunits
What happens first during the initiation of translation of building a polypeptide?
A small ribosomal subunit binds with mRNA and a special initiator tRNA
After a small ribosomal subunit binds with mRNA and a special initiator tRNA, what happens?
Small subunit moves along the mRNA until it reaches the start codon
Proteins called ______ _______ bring in the large subunit that completes the translation initiation complex.
During the elongation of the polypeptide chain, amino acids are...
added one by one to the preceding amino acid
Each addition of an amino acid during the elongation of the polypeptide chain involves proteins called _____ ___ and occurs in three steps.
Each addition of amino acids during the elongation stage of the polypeptide chain occurs in three steps:
1. Codon recognition
2. Peptide bond formation
Termination of translation occurs when..
a stop codon in the mRNA reaches the A site of the ribosome.
The release factor's reaction during termination of translation releases the __________ and the translation assembly then...
translation assembly then falls apart
A number of ribosomes can translate a single mRNA simultaneously, forming a _________.
polyribosome aka polysome
The change of ______ nucleotide in a DNA template strand can lead to the production of an abnormal protein.
The change of a single nucleotide in a DNA template strand can lead to the production of a(n)..
Point mutations within a gene are divided into two general categories. What are they?
-Base-pair insertions or deletions
Silent mutations have no effect on the amino acid produced by a codon because of..
redundancy in the genetic code
changes an amino acid codon into a stop codon, nearly always leading to a nonfunctional protein
Compare the effects of insertions/deletions to substitutions.
insertions/deletions have a disastrous effect on the resulting protein more often than substitutions do
mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide
When comparing gene expression, bacteria and eukarya differ in their...
termination of transcription,
When comparing gene expression, archae tends to resemble ____ in RNA polymerases, termination of transcription, and ribosomes.
In a nucleotide, the nitrogenous base is attached to the sugar's _____ carbon and the phosphate group is attached to the sugar's _____ carbon.
1' ; 5'
Why is the new DNA strand complementary to the 3' to 5' strands assembled in short segments?
DNA polymerase can assemble DNA only in the 5' to 3' direction
The synthesis of a new strand begins with the synthesis of a(n) _____.
RNA primer complementary to a preexisting DNA strand
Which part of a deoxynucleoside triphosphate (dNTP) molecule provides the energy for DNA synthesis?
Which of the following statements about Okazaki fragments in E. coli is true?
they are formed on the lagging strand of DNA
Which of the following enzymes is important for relieving the tension in a helix as it unwinds during DNA synthesis?
True or false? Single-stranded DNA molecules are said to be antiparallel when they are lined up next to each other but oriented in opposite directions.
What name is given to the process in which a strand of DNA is used as a template for the manufacture of a strand of pre-mRNA?
What name is given to the process in which the information encoded in a strand of mRNA is used to construct a protein?
What is the process called that converts the genetic information stored in DNA to an RNA copy?
Which of the following statements best describes the promoter of a protein-coding gene?
promoter is a nontranscribed region of a gene
What determines which base is to be added to an RNA strand during transcription?
Base pairing between the DNA template strand and the RNA nucleotides
Which of the following terms best describes the relationship between the newly synthesized RNA molecule and the DNA template strand?
What happens to RNA polymerase II after it has completed transcription of a gene?
It is free to bind to another promoter and begin transcription.
During RNA processing a(n) _____ is added to the 3' end of the RNA.
a long string of adenine nucleotides
Which of the following processes is an example of a post-translational modification?
Which of the following steps occurs last in the initiation phase of translation?
The large ribosomal subunit joins the complex.
True or false. A tRNA with an anticodon complementary to the stop codon catalyzes the reaction by which translation is terminated.
Which mutation(s) would not change the remainder of the reading frame of a gene sequence that follows the mutation(s)?
One addition and one deletion mutation.
If a mutated DNA sequence produces a protein that differs in one central amino acid from the normal protein, which of the following kinds of mutations could have occurred?
An addition mutation and a deletion mutation.
violation of the base-pairing rules in that the third nucleotide (5' end) of a tRNA anticodon can form hydrogen bonds with more than one kind of base in the third position (3' end) of a codon
one of a ribosome's three binding sites for tRNA during translation. It holds the tRNA carrying the growing polypeptide chain.
Codon (AUG) that signals to ribosomes to begin translation; codes for the first amino acid in a protein
A group of nucleotides that does not specify a particular amino acid, but instead serves to notify the ribosome that the protein being translated is complete. The stop codons are UAA, UGA, and UAG. They are also known as nonsense codons.
substitute one base pair for another, result is the same amino acid and has no phenotypic effect
The most common type of mutation, a base-pair substitution in which the new codon makes sense in that it still codes for an amino acid, just not the same one.
process in which polypeptides are chemically modified after being created
Where does replication, transcription, and translation occur?
transcription-cytoplasm of the cell
translation-ribosomes attach to the mRNA and translate it into a polypeptide
For each molecule of glucose that is metabolized by glycolysis and the citric acid cycle, what is the total number of NADH + FADH2 molecules produced?
During aerobic respiration, electrons travel downhill in which sequence?
food -> NADH -> Electron transport chain -> oxygen
In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + Pi to ATP?
Energy released from the movement of protons through ATP synthase
The oxygen consumed during cellular respiration is involved directly in which process or event?
accepting electrons at the end of the electron transport chain
How do the final electron acceptors differ between aerobic respiration, anaerobic respiration & fermentation?
Aerobic Respiration: oxygen is final electron acceptor
Anaerobic Respiration: inorganic or organic electron acceptors (usually an inorganic substance such as nitrate or sulfate)
Fermentation does not use electron transport chain.
Do photosynthesizing plants have mitochondria?
Yes, to supply the plants with the ATP needed to power various cell activites
adds to genetic variation because any sperm can fuse with any ovum (unfertilized egg)
fusion of 2 gametes produces a zygote with any of about 70 trillion diploid combinations
each zygote has unique genetic identity
What is the role of NADP+ in photosynthesis?
It is reduced to NADPH and then carries electrons to the Calvin cycle.
ribulose biphosphate; a five-carbon carbohydrate that combines with CO2 to form two molecules of PGA in the first step of the Calvin Cylce
What are products of the light reactions of photosynthesis that are used in the Calvin cycle?
ATP and NADPH
When oxygen is released as a waste product of photosynthesis, it is a result of ____.
Splitting water molecules
In mitosis, if a parent cell has 16 chromosomes, each daughter cell will have how many chromosomes?
If the liver cells of an animal have 24 chromosomes, the sperm cells would have how many chromosomes?
What are the three stages in interphase?
G1 phase ("first gap")
S phase ("synthesis")
G2 phase ("second gap")
Which phase of the cell cycle is incorrectly described?
a. G1: a time of slow cell growth
b. S: DNA is replicated
c. G2: A cell prepares for division
d. M: nuclear and cytoplasmic division
a. G1: a time of slow cell growth
Which of the following is true of a species with a chromosome number of 2n = 16?
a. Each cell has 8 homologous pairs.
b. The species has 16 pairs of chromosomes per cell.
c. The species is diploid with 32 chromosomes per cell.
d. During the S phase of the cell cycle there will be 32 separate chromosomes.
e. A gamete from this species has 4 chromosomes.
a. Each cell has 8 homologous pairs.
Which phase of the cell cycle is incorrectly described?
a. G1: organelles are replicated
b. S: DNA is replicated
c. G2: replicated DNA separates
d. M: nuclear and cytoplasmic division occurs
c. G2: replicated DNA separates
Meiosis versus Mitosis
-Mitosis conserves the number of chromosome sets, producing cells that are genetically identical to the parent cell.
-Meiosis reduces the number of chromosomes sets from two (diploid) to one (haploid), producing cells that differ genetically from each other and from the parent cell
-The mechanism for separating sister chromatids is virtually identical in meiosis II and mitosis.,
-Mitosis results in a diploid daughter cell (46 paired chromosomes). --Meiosis gives a haploid gamete of 23 unpaired chromosomes.
-Mitosis takes place in somatic (Tissue) cells.
-Meiosis takes place in gamete production and maturation
-Mitosis is a single step process (although it has many phases).
-Meiosis can be considered as two cell divisions Meiosis I and Meiosis II.
When does DNA replication occur in Mitosis?
When does DNA replication occur in Meiosis?
Mitosis - occurs during interphase before mitosis begins
Meiosis - occurs during interphase before meiosis I begins
When does synapsis of homologous chromosomes occur in meiosis?
Occurs during Prophase I along with crossing over between nonsister chromatids
Number of daughter cells in Mitosis?
2 (each diploid (2n) and genetically identical to the parent cell)
Number of daughter cells in Meiosis?
4 (each haploid (n) containing half as many chromosomes as the parent cell; genetically different from the parent cell and from each other)
Mitosis' role in the animal body
enables multicellular adult to arise from zygote;
produces cells for growth, repair, and in some species, asexual reproduction
Meiosis' role in the animal body
reduces number of chromosomes by half;
introduces genetic variability among gametes
3 mechanisms that contribute to genetic variation:
1. Independent assortment of chromosomes
2. Crossing over
3. Random fertilization
Independent Assortment of Chromosomes
each pair of chromosomes sorts maternal and paternal homologues into daughter cells independently of the other pairs, homologous pairs of chromosomes orient randomly at metaphase 1 of meiosis, each pair of chromosomes sort maternal and paternal homologues into daughter cells independently of other pairs
Produces recombinant chromosomes;
begins very early in prophase I, as homologous chromosomes pair up gene by gene
homologous portions of two nonsister chromatids trade places
contributes to genetic variation by combining DNA from two parents into a single chromosome
Photosynthesis generates ___ and ___.
O2 and organic molecules (which are used in cellular respiration)
-Combine simple organic substances into more complex organic molecules
Redox Reactions & Dehydrogenation;
Glucose is oxidized, Oxygen is reduced
(formula is that of the carbohydrate catabolism)
loss of hydrogen ions at the same time as removal of electrons in cellular oxidations
Some are free in ______; others are attached to ____ _____ of ________.
some are free in CYTOPLASM; others are attached to INNER MEMBRANE of MITOCHONDRIA
Each NADH represents ____ ____ that will eventually be used to make ____.
each NADH represents STORED ENERGY that will eventually be used to make ATP.
Attached electron carriers are located in the ______ ______ ______ in the ________.
Electron Transport Chain (ETC);
Step 1: The electron transport chain (ETC) passes ________ in a series of steps called _______ ______.
The electron transport chain (ETC) passes ELECTRONS in a series of steps called REDOX REACTIONS
Step 2: Energy is _____ during the step-wise process (redox reactions) due to the ETC.
Step 3: The energy released from redox reactions in the ETC is used to make ____.
Step 4: Electrons are finally ______ by ______ (final electron acceptor).
Electrons are finally ACCEPTED by OXYGEN
(Generation of ATP)
Energy released during oxidation is _____ within the cell by formation of _____.
Energy released during oxidation is TRAPPED within the cell by formation of ATP.
3 Mechanisms for phosphorylation:
1. Substrate-level Phosphorylation
2. Oxidation Phosphorylation
High energy phosphate group from a substrate is added directly to ADP;
Substrate is usually an organic molecule that is an intermediate in a catabolic pathway
ATP is synthesized during the series of redox reactions that take place in the Electron Transport Chain
occurs during photosynthesis, The process of generating ATP from ADP and phosphate by means of a proton-motive force generated by the thylakoid membrane of the chloroplast during the light reactions of photosynthesis.
4 Key Metabolic Stages of Aerobic Respiration:
2. Transition Stage
3. Krebs Cycle (Citric Acid Cycle)
4. Oxidative Phosphorylation
Yield from one glucose:
-2 ATPs (net) via substrate-level phosphorylation
If ______ is present, pyruvate enters the _______.
if OXYGEN is present, pyruvate enters the MITOCHONDRIA
Once pyruvate enters the mitochondria (and oxygen is present), it is converted to ______ which occurs in the _________ ________.
Acetyl CoA; Mitochondrial matrix
From Transition Stage, Acetyl-CoA enters the Citric Acid Cycle by combining with ______ ______.
The seven steps after Acetyl-CoA combines with oxaloacetic acid in the Citric Acid Cycle include _____ and _____ of ______.
The seven steps after Acetyl-CoA combines with oxaloacetic acid in the Citric Acid Cycle include OXIDATION and BREAKDOWN of SUBSTRATES.
In the last step of the Citric Acid Cycle _______ _____ is regenerated thus making it a cycle.
High energy electrons are transferred from co-enzymes to the _____ .
ETC (Electron Transport Chain)
In the ETC - step wise release of ____ occurs as _________ are transferred from one electron carrier to another.
energy ; electrons
the use of energy in a H+ gradient to drive cellular work; exergonic flow of H+ through ATP synthase drives synthesis of ATP
In the ETC, each electron transfer is a ________ reaction and is associated with ________ _______.
In the ETC, each electron transfer is a REDOX reaction and is associated with ENERGY RELEASE.
Energy release is ______ to pumping of hydrogen ion into the __________ space of the _______.
Energy release is COUPLED to pumping of hydrogen ion into the INTERMEMBRANE space of the MITOCHONDRIA.
Reduced co-enzymes that enter ETC:
Glycolysis = __ NADH
Transition Stage = __ NADH
Citric Acid Cycle = __ NADH + __ FADH2
TOTAL ATP = ___ ATPs
Reduced co-enzymes that enter ETC:
Glycolysis = 2 NADH
Transition Stage = 2 NADH
Krebs Cycle = 6 NADH + 2 FADH2
Total = 10 NADH + 2 FADH2
Total = 30 ATPs + 4 ATPs = 34 ATPs
Total Theoretical ATP yield from 1 glucose molecule during aerobic respiration:
Glycolysis: __ ATPs
Transition Stage: __ ATPs
Citric Acid Cycle: __ ATPs
ETC: __ ATPs
TOTAL: __ ATPs from one glucose molecule
NOTE: Some cells yield only __ ATPs
Glycolysis: 2 ATPs (substrate level phosphorylation)
Transition stage: 0 ATP
Krebs Cycle: 2 ATPs (substrate level phosphorylation)
ETC: 34 ATPs (oxidative phosphorylation)
Total: 38 ATPs from one glucose molecule
Note: Some cells yield only 36 ATPs
Final electron acceptor is ___ oxygen in anaerobic respiration; the final electron acceptor is usually an __________ __________.
NOT; inorganic substance
Fermentation does or does not use an electron transport chain?
DOES NOT use an electron transport chain
In alcohol fermentation, pyruvate is converted to _________ in ____ steps, the first step releasing _______.
Ethanol; 2 steps; CO2
In Lactic Acid Fermentation pyruvate is reduced to ____, forming ______ as an end product, with no release of CO2.
_______ _____ cells use lactic acid fermentation to generate ATP when O2 is scarce.
Human Muscle Cells
Final Electron Acceptors for Aerobic Respiration, Anaerobic Respiration, and Fermentation.
Aerobic - oxygen
Anaerobic - inorganic molecule
Fermentation - organic molecule
ATP Production in Aerobic Respiration, Anaerobic Respiration, and Fermentation.
Aerobic - 38 ATPs
Anaerobic - varies
Fermentation - 2 ATPs
proteins break down in to amino acids and undergo a variety of conversions; products can enter glycolysis or kreb's cycle
Structural organization of the chloroplasts allow for the chemical reactions of __________.
Chloroplasts are structurally similar to ___________ ________.
Photosynthetic Bacteria (probably where they came from to begin with)
Green color in plants is from ________, the green pigment within __________.
_______ ________ absorbed by ___________ drives the synthesis of organic molecules in the chloroplast.
Light energy; chlorophyll
Three membranes of chloroplast's structure are:
1. Smooth outer membrane
2. Smooth inner membrane
3. Complex third membrane
What are the 2 stages of photosynthesis?
Light Dependent Reactions & Light-Independent Reactions (Calvin Cycle)
In Light Dependent Reactions, ______ ______ (which involves chlorophyll) converts in to ________ _________ _________.
Light Energy; High Energy Compounds
In light-independent reactions (aka The Calvin Cycle) ______ & ________ are used to make __________ from _____.
ATP & NADPH are used to make CARBOHYDRATES from CO2
_____ _____ have the shortest wavelength and the highest energy.
(X-Rays & UV are same pattern)
_______ ______ have the longest wavelength with the lowest energy.
(infrared & microwaves are same pattern)
3 Characteristics of Light:
1. Travels in waves
2. Behaves as a particle
3. Photons can interact with atoms
When photons interact with atoms, they can _____ electrons to a _______ energy level.
Two things can happen when photons interact with atoms. They can either _____ to ground state which can create fluorescence, or excited electrons _____ atom and go to an ______ ______ _______.
Two things can happen when photons interact with atoms. They can either RETURN to ground state which can create fluorescence, or excited electrons LEAVE atom and go to an ELECTRON ACCEPTOR MOLECULE.
What sequences correctly represents the flow of electrons during photosynthesis?
H2O--> NADPH-->Calvin cycle
In the electromagnetic spectrum, the type of radiation that we call visible light occurs between _____.
ultraviolet radiation and infrared radiation
Light energy during light-dependent reactions is used to do two things.
1. Make ATP
2. Reduce NADP+ to NAPH2
Light-Dependent Reactions involves ________ __ and _________ ______.
Chlorophyll A and Accessory Pigments
What do light-harvesting complexes do in photosystems I & II?
funnel the energy of photons to the reaction center
In photosystems I & II, a primary electron acceptor does what in the reaction center?
It accepts an excited electron from chlorophyll a
What is the first step of the light reactions in photosystems?
Solar-powered transfer of an electron from a 'chlorophyll a' molecule to the primary electron acceptor
Two types of photosystems in the thylakoid membrane:
1. Photosystem II (PS II)
2. Photosystem I (PS I)
During the light-dependent reactions, there are two possible routes for electron flow:
1. Linear electron flow
2. Cyclic electron flow
In linear electron flow, a pigment and its energy is passed among _____ ______ until it excites _____.
Pigment molecules; P680
In linear electron flow, an excited electron from P680 is ________ to the ______ _______ ______.
transferred; primary electron acceptor
In linear electron flow, H2O is split by _________, and the ______ are transferred from the hydrogen atoms to P680+ thus reducing it to ______.
enzymes, electrons, P680
In linear electron flow after P680+ is reduced to P680, ____ is released as a by-product of the reaction.
In linear electron flow, each electron "falls" down an _________ ________ _____ from the primary electron acceptor of PS II to PS I.
electron transport chain
In linear electron flow, energy released by the fall drives the creation of a _____ ______ across the _______ membrane.
proton gradient; thylakoid
Diffusion of H+ (protons) across the membrane after creation of the proton gradient across the thylakoid membrane drives _____ ______.
In linear electron flow, In PS I (like PS II), transferred light energy excites _____, which loses an ______ to an _______ ______.
P700, Electron, Electron Acceptor
In linear electron flow, P700+ (P700 that is missing an electron) _________ an electron passed down from PS ___ through the _______ ________ _______.
accepts, PS II, Electron Transport Chain
In linear electron flow, each electron "falls" down an electron transport chain from the primary electron acceptor of _____ to the protein, ___________.
PS I, Ferredoxin (Fd)
In linear electron flow, after the electrons have "fallen" down to the protein, ferredoxin, the electrons are then transferred to _______ and _______ it to _________,
NADP+ and reduce it to NADPH
In linear electron flow, after electrons are transferred to NADP+ and have reduced it to NADPH, the electrons are available for the reactions of the ________ ________.
Cyclic electrong flow uses only __________ and produces ____, but not _______.
Uses only PS I and produces ATP, but nottttt NADPH
In cyclic electron flow, in PS I, light energy excites ______ which causes the electron to be ___________ to the __________ ________.
Light energy excites P700, which causes the electron to be TRANSFERRED to the ELECTRON ACCEPTOR.
In cyclic electron flow, once electrons are transferred to electron acceptor, photoexcited electrons are _________ to ___________ which is _______ to ________ ________ , and then back to ________.
In cyclic electron flow, once electrong are transferred to electron acceptor, photoexcited electrons are TRANSFERRED to FERREDOXIN (Fd) which is TRANSFERRED to CYTOCHROME COMPLEX and back to P700.
_________ _________ _________ occurs when there are low concentrations of NADP+.
Cyclic Electron Flow
In chemiosmotic generation of ATP, electrons are transferred through chain of _________ _________ where energy is ___________. From there, energy pumps ______ (H+) from _______ to __________ space. This allows H+ concentration to __________. Then, H+ diffuses by _________ back to _______ via ATP synthase enzyme. Then, energy is released as ___ flows through. The energy is used for ______ + ___ which creates ATP.
In chemiosmotic generation of ATP, electrons are transferred through chain of ELECTRON-ACCEPTORS where energy is GENERATED. From there, energy pumps PROTONS (H+) from STROMA to THYLAKOID space. This allows H+ concentration to INCREASE. Then, H+ diffuses by DIFFUSION back to STROMA via ATP synthase enzyme. Then, energy is released as H+ flows through. The energy is used for ADP + Pi which creates ATP.
Light-Independent Reactions are also called the ______ _______ or _______ ______.
Calvin cycle, dark reactions
The calvin cycle, builds _______ from smaller molecules by using ____ and the reducing power of electrons carried by ______.
Carbon enters the calvin cycle as CO2 and leaves as a _________ named __________.
Sugar ; glyceraldehyde-3-phosphate (G3P)
For net synthesis of 1 G3P, the calvin cycle must turn ___ times, fixing ___ molecules of CO2.
3 ; 3
3 Phases of the Calvin Cycle:
1 Carbon fixation
3 Regeneration of the CO2 acceptor (RuBP)
In Calvin Cycle, _______ _______ combines with ________ which generates ___ carbon molecule.
Carbon dioxide; RuBP; 6
6-C molecules in Calvin Cycle instantly _____ into _____ molecules of _________.
SPLIT into TWO molecules of PHOSPHOGLYCERATE (3-C)
Phosphoglycerate is converted to ____ in the calvin cycle; uses ____ & _____ from ____________ reactions.
G3P ; ATP & NADHP ; light-dependent
When comparing chemiosmosis in chloroplasts and mitochondria, ____ generate ATP by chemiosmosis, but use _________ sources of energy.
both ; different
When comparing chemiosmosis in chloroplasts and mitochondria, mitochondria transfers ____ energy from ____ to ATP. Chloroplasts transforms ___ energy into the ______ energy of ATP.
chemical ; food ; light ; chemical
When comparing chemiosmosis in chloroplasts and mitochondria- in mitochondria, protons are pumped to the ____________ space and drive ATP synthesis as they ______ back into the ________ _______.
protons are pumped to the INTERMEMBRANE space and drive ATP synthesis as they DIFFUSE into the MITOCHONDRIAL MATRIX.
When comparing chemiosmosis in chloroplasts and mitochondria - in chloroplasts, protons are pumped into the _______ space and drive ATP synthesis as they _______ back into the _____.
Thylakoid space, diffuse, stroma
Photosynthesis consists of the ______ _______ (the "photo" part) and the _______ _________ (the "synthesis" part).
Summary of light reactions:
They are in the __________.
1. Split ________
2. Release ____
3. Reduce ______ to ________
4. Generate ATP from ADP by ___________.
They are in the thylakoids
1. split H2O
2. release O2
3. Reduce NADP+ to NADPH
4. Generate ATP from ADP by PHOTOPHOSPHORYLATION
The Calvin Cycle (in the ______) forms _________ from CO2, using _______ & _______.
ATP & NADPH
Calvin Cycle begins with __________ ____________, incorporating CO2 into __________ molecules.
Carbon fixation, organic
On hot, dry days, plants close _______, which conserves ____ but also limits _________.
stomata, H2O, photosynthesis
Photorespiration consumes _____ and ______ fuel and releases ______ without producing ___ or ______.
O2, organic, CO2, ATP, sugar
Photorespiration may be an evolutionary relic because rubisco first evolves at a time when the atmosphere had far less O2 and more CO2.
Multicellular organisms depend on cell division for:
Growth and Development
Chromosomes consist of ______, a complex of DNA and protein that condenses during cell division.
In preparataion for cell division, _____ is replicated and the chromosomes _____.
DNA ; chromosomes condense
Each duplicated chromosome has two ________ ________, which separate during cell division.
narrow waist of the duplicated chromosome, where the two chromatids are most closely attached
The cell cycle consists of the M phase which is properly known as the _________ phase. ________ & ________ occur during this phase.
Mitosis and cytokinesis
The Centrosome ________, forming ______ centrosomes that migrate to ________ ends of the cell, as spindle microtubules grow out of them.
replicates, 2, opposite
During prometaphase, some spindle microtubules attach to the _______ of chromosomes and begin to _____ the chromosomes.
kinetochores ; move
By end of interphase...
Chromosomes are _______
Centrosome has _____
Nuclear membrane is _____
Nucleus has ______
Chromosomes are replicated (2 copies)
Centrosome has duplicated
Nuclear membrane still intact
Nucleus has nucleoli
In prophase, duplicated chromosomes appear as two ______ ______ ________ _____ ; still joined by ______.
identical sister chromatids ; centromere
In prophase, centrosomes _______ _____ and begin to _______ to _______ ends of the cells.
move apart ; migrate ; opposite
For each chromsome, __________ of sister chromatid are attached to ________ __________ coming from opposite poles.
kinetochores; kinetochore tubules
Sister chromatid ______ from each other which becomes a full-fledged _______.
separate ; chromosome
Kinetochore microtubules attached to centromere of each sister chromatid begin to ________ --> chromosomes move _______ first.
shorten ; centromere
At the end of anaphase, the ends of the cell have _____ and _______ collections of chromosomes.
complete & identical
in animals, cytokinesis occurs by a process known as ________, forming a _________.
cleavage ; cleavage furrow
Contractile Ring, what is it made of? and where does it form?
made of microfilaments
forms on cytoplasmic side
Microfilaments _______, then the cleavage furrow _______, then the cell gets _______ into 2 new daugher cells.
contract; deepens; pinched
_____ _____ gives rise to the plasma membranes and cell walls of the two daughter cells in plant cells.
chromosome replicates (beginning at the origin of replication), and the two daughter chromosomes actively move apart
invades surrounding tissues and can metastasize (export more cancerous cells to the body), where they may form secondary tumors
Meiosis I =
Meiosis II =
homologous chromosomes separate (meiosis i)
sister chromatids separate (meiosis ii)
Mitosis ______ the number of chromosome sets, producing cells that are ________ to the parent cell.
conserves ; genetically identical to the parent cell
Meiosis _____ the number of chromosome sets from ___ to ___, producing cells that _______.
reduces ; from 2 to 1 ; differ genetically from each other and from the parent cell
The mechanism for separating sister chromatids is virtually _______ in meiosis ii and mitosis.
3 Events unique to Meiosis (all occuring in meiosis I)
1. Synapsis and crossing over in prophase I
2. At the metaphase plate, there are paired homologous chromosomes (tetrads), instead of individual replicated chromosomes.
3. Anaphase I : homologous chromosomes, instead of sister chromatids separate
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