Exam 2 Flashcards
1
Q
The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is best know as
A
Feedback inhibition
2
Q
A strand of DNA is 30% A. What percentage of it is made up of thymine?
A
30%
3
Q
What is a passive process in which molecules move from a region of higher concentration to a region of lower concentration
A
Diffusion
4
Q
What types of bonds form between the monomers that make up carbohydrates?
A
Glycosidic
5
Q
What type of bonds form between the monomers that make up lipids?
A
Ester
6
Q
Proteins are polymers made up of monomers known as
A
Amino acids
7
Q
How do enzymes increase the speed of certain biological chemical reactions?
A
By bringing reactants into physical contact with one another
8
Q
The kinds of molecules that pass through a cell membrane most easily are
A
Small and hydrophobic
9
Q
The type of bond that forms between two nucleotides is known as a
A
Phosphodiester bonds
10
Q
What is the term for metabolic pathways that release stored energy by breaking down complex molecules?
A
Catabolic pathways
11
Q
What is NAD+ reduced to and when?
A
To NADH during glycolysis, pyruvate oxidation, and the citric avid cycle
12
Q
What kind of metabolic poison (toxin) would most directly interfere with glycolysis?
A
An agent that closely mimics the structure of glucose but is not metabolized
13
Q
In glycolysis, for each molecule of glucose oxidized to pyruvate ________ molecules of ATP are used and ________ molecules of ATP are produced
A
2
4
14
Q
The glucose molecule has a large quantity of energy in its _______
A
C-H bonds
15
Q
Why might adding inorganic phosphorus to a reaction mixture where glycolysis is rapidly proceeding help sustain the metabolic pathway?
A
The metabolic intermediates of glycolysis are phosphorylated
16
Q
The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction _________
A
Loses electrons and loses potential energy
17
Q
Why is glycolysis described as having an investment phase and a payoff phase?
A
It uses stored ATP and then forms a net increase in ATP
18
Q
In addition to ATP, what are the end products of glycolysis?
A
NADH and pyruvate
19
Q
A strand of DNA is 12% C. What percentage of it is made up of T?
A
38%
20
Q
Using only single bonds, how many hydrogen atoms would it take to covalently bond to one carbon atom before molecule would become most stable?
A
4
21
Q
A cellular membrane that has no cholesterol molecules dispersed throughout phospholipids. If you were to place this organism in an extremely hot environment, what would you expect to see change in regard to cell membrane permeability?
A
The membrane would become more permeable to glycerol
22
Q
What kind of reactions link monosaccharides together to form carbohydrates?
A
Dehydration/condensation
23
Q
Product A binds to the enzyme that converts X to Y at a position remote from its activation site. The binding decreases the activity of the enzyme. What is the substance A?
A
An allosteric inhibitor
24
Q
What two molecules are the major structural components of the cell membrane?
A
Phospholipids and Proteins
25
What do prokaryotes include?
Ribosomes
Simple cytoskeleton
Specialized membranes for photosynthesis and the storage of ions or enzymes
26
What does a prokaryote have instead of a nucleus?
Nucleoid
27
What is the shape of chromosomes in prokaryotes?
Circular
28
What are prokaryote’s cell walls made of?
Peptidoglycan
29
What do prokaryotes contain?
Nucleoid
Plasmids
Circular chromosomes
30
What do eukaryotes contain?
Nucleus
| Complex organelles
31
What do prokaryotes and eukaryotes both contain?
Ribosomes
DNA
Cell Wall
Plasma Membrane
32
You have found that an unknown cell type contains DNA, ribosomes, and circular plasmids. Based off this information you know that....
That it is a prokaryote
33
What are bacterial cells walls made of?
Peptidoglycan
34
If you are observing a prokaryotic cell under a microscope, which would you expect to find?
A circular chromosome
| And ribosomes
35
What happens if the surface area to volume ratio is too small?
Then the cell can’t get rid of waste or take up nutrients fast enough
36
Which is the most ideal set of conditions for a cell?
Small volume and large surface area
37
What does the endomembrane system include?
```
Cell membrane
Endoplasmic reticulum (rough and smooth)
Golgi apparatus
Lysosomes
Peroxisomes
Vesicles
```
38
What do ribosomes help with?
Protein synthesis
39
Where do ribosomes start out?
Free-floating in the cytoplasm
40
Where are the two places ribosomes can go form the cytoplasm?
- stay in the cytoplasm
| - dock with the ER if the protein they are making requires it
41
What is a ribosome dock based on?
Signal sequence
42
What does the signal sequence allow a ribosome to do?
To bind to an SRP (signal sequence receptor) which binds to a receptor on the ER
43
Where does a ribosome go after the ER?
(Phagocytosis)
- packaged into transport vesicles
- sent to the Golgi apparatus
- can then be packaged into lysosomes
44
What are necessary for the endomembrane system to function properly?
Vesicles
45
What do vesicles do?
They help transport the products from the ER to the Golgi apparatus and so on
46
How do vesicles move around the cell so easily?
Motor proteins such as kinesins
47
What are kinesins made of?
2 subunits twisted together
48
What is the structure of kinesins?
Has a head, a stall, and a tail
49
What do the tails of kinesins do?
Bind to the vesicle while the heads bind to the microtuble “highways” throughout the cell
50
What do the heads of kinesins?
“Walk” along the microtubles, moving the vesicle around the cell
51
What does each “step” of kinesins require?
ATP
52
A free floating ribosome attaches to a piece of mRNA in the cytoplasm. When protein synthesis begins, no ER signal sequence is present. What is the final destination of this protein?
It will remain within the cell’s cytoplasm
53
A protein has been packaged into vesicle to be to be secreted. What signal sequences did the mRNA contain that were integrated into the final protein?
ER signal
54
A cell acquires a mutation to its DNA that causes the Zip Code and Transmembrane sequences to become unreadable in the final protein? Where is the most likely destination for this protein?
It will be secreted to the outside of cell
55
Which organelle is NOT directly involved in the Endomembrane system?
Mitochondria
56
What is the order of events of a protein that has an ER and Zip code signal sequence?
- Protein translation beings with a ribosome
- Protein is synthesized in the rough ER
- Protein is transported in vesicle to the Golgi apparatus
- Protein is transported in vesicle to a lysosome
57
what is substance that resides within the cell’s plasma membrane, but outside of all other cellular organelles and/or compartments?
cytoplasm
58
What is cytoplasm thickened with?
with ions, salts, and dissolved polar biomolecules
59
Which cells so not have a nucleus?
prokaryotic
60
What resides in the nucleoid?
circular DNA chromosome of these cells compacts with the help of some associated proteins for prokaryotes
61
What is the nucleus?
Organelle that encapsulates the DNA of eukaryotic cells
62
What is the nuclear envelope?
the double-phospholipid bilayer on the surface of the nucleus
63
What is the nucleolus?
darkly stained region within the nucleus
64
Where can molecules pass through the bilayers of the nucleus's surface?
nuclear pores
65
What is a combination of proteins and rRNA that does not have membrane?
ribosome
66
What do ribosomes do?
Takes information from mRNA and assembles amino acids into a protein (translation)
67
What is rough endoplasmic reticulum?
Organelle attached to the nucleus that is composed of stacks of flattened, circular membranes that are much like the outer cell membrane
68
Why is rough ER considered rough?
because the surface of these membranes are studded with ribosomes
69
What is the function of the rough ER?
the synthesis and packaging of proteins for export to outside of the cell
70
What is smooth endoplasmic reticulum?
Organelle found directly outside of the rough ER that is also composed of stacks of flattened, circular membranes that are much like the outer cell membrane
71
Why is smooth ER considered smooth?
because the surface of these membranes are NOT studded with ribosomes
72
What does smooth ER contain?
enzymes for carbohydrate and lipid synthesis and/or degradation
73
What is the golgi apparatus?
Organelle found directly outside of the ER that is also composed of stacks of flattened, circular membranes much like the outer cell membrane
74
What is the function of the golgi apparatus?
receiving vesicles, sorting the contents, and re-packaging the contents into a new vesicle to be shipped to a new location
75
What are the two sides of the golgi?
cis side and the trans side
76
What does the cis side of the golgi do?
receives vesicles. Because the membranes are similar to the ER, the vesicles fuse with the golgi and dump their contents inside
77
What is a lysosome?
Organelle that is a product of the golgi
78
What makes mitochondria and chloroplasts different from other organelles?
Both have 2 membranes
Have their own DNA
“Reproduce” through binary fusion
Very similar to the traits of prokaryotes
79
What is outside the plasma membrane?
The extracellular matrix
80
What does the the extracellular matrix help with?
Cell-cell communication, cell-type identity, self-identify (like in the immune system)
81
What is the extracellular matrix made up of?
Integrins, microfilaments of the cytoskeleton, collagen fibers, proteoglycan molecules, polysaccharide molecules and proteoglycan complex
82
How do plant cells communicate?
Channels between cells through cell walls: plasmodesmata
83
How do animal cells communicate?
Gap junctions: span the space between cells to form a channel, directly connecting the cytoplasm of adjacent cells, allows molecules to pass in between
84
What do tight junctions do?
Holds the membrane of 2 cells together to prevent anything from leaking in between them
85
What is lipid soluble signaling?
Lipid soluble signals are able to pass through the membrane
| They bind with a receptor inside the cytosol of the cell and can bind directly to the targeted gene on DNA
86
What are lipid insoluble signals?
Unable to pass through the membrane
Bonds with a receptor protein on the outside of the cell
—signal must be transducers into the cytoplasm where it is amplified so it can bind to the DNA
87
How do plant cells communicate with each other?
Plasmodesmata
88
If an animal cell wanted to send molecules to an adjacent cell, which type of a cell-cell communication would it use?
Gap junctions
89
If a signaling molecule is hydrophobic (like a steroid) how would you expect the signal to interact with the cell?
Passes through the membrane and bonds directly to the DNA
90
What are the uses of food in the body?
Used for cellular respiration
| Used for biosynthesis
91
How is NAD+ like a rechargeable battery?
Stores energy
| Can be used over and over again
92
Do plants still need to perform cellular respiration?
Yes
93
Which type of macromolecules are broken down to ultimately make ATP?
All of them
94
What enzyme splits glucose?
aldolase
95
Is the majority of the energy from glucose harvested during glycolysis?
No
96
What is the "ATP math" of glycolysis?
2 used + 4 gained = +2
97
In what organisms does alcoholic fermentation occur?
yeast and some types of bacteria
98
What is the product of alcoholic fermentation that is toxic to cells?
ethanol
99
In what organisms does lactic acid fermentation occur?
animals
100
What is the product of pyruvte processing?
Acetyl CoA
101
How many times will the Krebs cycle turn when 1 glucose is used?
Twice
102
What does the citric acid cycle do?
finishes oxidizing glucose
103
Are the citric acid cycle and the Kreb's cycle the same thing?
yes
104
What does the Krebs cycle start and end with?
Citrate
| oxalocetate
105
What does one spin of the citric acid cycle produce?
2 CO2
3 NADH
1 ATP
1 FADH2
106
How many of each electron carrier is made by one glucose during aerobic cellular respiration?
10 NADH, 2 FADH2
107
What part of cellular respiration requires O2?
ETC and Oxidative Phosphorylation
108
What does the ETC and oxidative phosphorylation use from previous processes?
NADH and FADH2
109
What is Oxidative Phosphorylation?
the biggest contributor to ATP production
110
Where does ETC and Oxidative phosphorylation?
across inner membrane of mitochondria
111
Electrons _____ energy as they're passed through the ETC
lose
112
Where does the energy that the electrons lose throughout the ETC go towards?
powering proton pumps, causing H+ ions to pass through the membrane into the inner membrane space
113
What does the movement of H+ out of the matrix create?
a concentration gradient
114
H+ _______ through the ATP synthase
passively diffuses
115
What is phosphorylation?
adding of phosphate group (s)
116
What does the potential energy created by the gradient become?
kinetic energy
117
How does the shift of energy happen?
spinning of ATP synthase's rotor
118
what does kinetic energy facilitate?
the phosphorylation of ADP
119
How many H+ ions enter ATP synthase to make 1 ATP?
3
120
About how many ATP does oxidative phosphorylation create?
34
121
What other macromolecules does cellular respiration use besides glucose?
larger sugars, lipids, and proteins
122
During which stage of cellular respiration is O2 used?
Oxidative phosphorylation
123
Which stage of aerobic respiration does NOT take place in the mitochondria?
Glycolysis
124
Which stage of cellular respiration produces the most ATP?
Oxidative phosphorylation
125
What is the summary the cellular respiration?
Glucose -> NADH -> ETC -> proton motive force -> ATP -> cellular work
126
What are the outputs of cell respiration?
CO2 and H2O
127
Do animals and plants have mitochondria?
yes
128
Which consumer will gain the most energy from their meal?
primary consumer
129
What are the elements of the chloroplasts?
thylakoid and stroma
130
What is in the thylakoid?
pigments and ETC
131
What is in the stroma?
liquid and Enzymes for CO2
132
What reaction occurs in the chloroplast?
Calvin cycle and the ETC
133
What gives plants their characteristic green coloration?
Chlorophyll
134
What part of the chloroplast is the primary location of the ETC ?
thylakoid membrane
135
What are the pigments involved in photosynthesis?
Chlorophyll a
Chlororphyll b
Carentenoids
136
Why don't albino plants tend to survive for long?
They reflect all light waves and the ETC can not proceed
137
What would likely happen if you grew a plant under a green light?
The plant will not grow much at all
138
Which wavelength/ color of light would provide more energy to the Light-Dependent reactions?
blue
139
Which would be the most likely result if the ETC in Photosystem I did not fully transport the electrons?
There would not be enough NADPH fro reverse glycolysis to optimally occur
140
What are the inputs of the Light-Dependent reactions?
ADP, Pi, NADP+, H+, Water
141
Which processes of the calvin cycle require energy?
Reduction/Reverse Glycolysis
| Regeneration of RuBP
142
What are the inputs of the Light-Independent Reactions?
**
143
What would be the most likely effect of Rubisco fixing to O2 rather than Carbon in CO2?
No glucose would be produced because of the reduced amount of G3P produced
144
What are the three experiments relevant to DNA?
- The Griffith Experiments
- The Hershey-Chase Experiment
- The Meselson-Stahl Experiments
145
Where the rough strain cells able to resurrect the heat-killed smooth strain cells?
no, they did not resurrect the dead cells
146
What was the difference between the Rough Strain and Smooth strain bacteria?
The Smooth Strain Bacteria had a capsule that protected the bacteria from the immune responses
147
What was the main idea of the Griffith Experiments?
R cells obtained information from the Heat-killed S cells which allowed the R cells to become living S cells
148
What is the process of bacteria obtaining foreign DNA from other bacteria?
Transduction
149
What is the best definition of a bacteriophage?
A type of virus that attack bacteria cells in a parasitic manner
150
What was the main idea of the Hershey-Chase Experiment?
Capsid portion of bacteriophage stayed on outside of the cell (as seen with the radioactive protein)
Virus DNA was injected into the cell (as seen with the radioactive DNA)
151
During the Meselson-Stahl experiments, what was the significance of growing bacteria in various mediums containing nitrogen isotopes such as 14N or 15N?
Bacteria will inevitably use the isotopes while synthesizing DNA; therefore placing an identifiable "marker" in the DNA
152
What was the order of events of the Meselson-Stahl Experiments?
1) Start with bacteria with 15N DNA (Gen 0)
2) Allow Gen 0 to replicate in 14N medium (Gen 1)
3) Allow Gen 1 to replicate in 14N medium (Gen 2)
4) Each generation was centrifuged and DNA was analyzed
153
What type of bonds hold complementary base pairs together?
hydrogen
154
Which direction is DNA synthesized?
5' -> 3'
155
How do nucleic acids polymerize?
by adding at the 3 carbon
156
Where will the RNA primer be placed in order to synthesize the other strand?
3' end
157
What why do strands run?
anti-parallel
158
Which protein primes the 3' end?
primase
159
Does DNA replication begin at the very end of the strand?
NO
160
Why does the DNA replication not start at the very end?
it would take too long to replicate the entire genome with just one set of proteins
161
_________ sites are far more efficient
multiple replicating
162
What does helicase do?
catalyzes the breaking of hydrogen bonds between base pairs to open the double helix
163
what do single-strand DNA binding proteins do?
stabilizes single-stranded DNA
164
What does topoisomerase do?
breaks and rejoins the DNA double helix to relieve twisting forces caused by the opening of the helix
165
What does the primase do?
catalyzes the synthesis of the RNA primer
166
What does the DNA polymerase III do?
extends the leading strand
167
what does the sliding clamp do?
holds DNA polymerase in place during strand extension
168
If primes failed to place the RNA primer during leading strand synthesis. how will DNA Polymerase III be affected?
fail to synthesize the leading strand properly since it does not have a starting place
169
What does polymerase I do?
removes the RNA primer and replaces it with DNA
170
What does DNA ligase do?
catalyzes the joining of Okazaki fragments into a continuous strand
171
What does telomerase do?
it elongates the end of the lagging strand so a DNA Polymerase can finish its replication
172
What is a reasonable explanation fro the apparent bending between the mismatched nucleotides?
do not properly form hydrogen bonds with each other
173
What protein would fix the mistake of the bending between mismatched nucleotides?
DNA Polymerase I
174
In addition to ATP, what are the end products of glycolysis?
NADH and pyruvate
175
Inside an active mitochondrion, most electrons follow which pathway?
citric acid cycle → NADH → electron transport chain → oxygen
176
Which electron carrier(s) function in the citric acid cycle?
NADH and FADH2
177
Which of the following factors would tend to increase membrane fluidity?
a greater proportion of unsaturated phospholipids
178
The enzyme that joins the small fragments of the lagging strand together into a continuous strand is called _______.
DNA ligase
179
What structures have a circular chromosome?
Mitochondria
Chloroplasts
Prokaryotic Cells
180
During exercise, the body is starving for oxygen which causes multiple changes in the way our cells function. What is/are the possible consequence(s) of this lack of oxygen?
- Pyruvate will be converted to lactic acid causing immediate muscle “burn”
- The electron transport chain begins to stall leaving the cell starving for energy
181
The light-independent reactions of plants function to make organic molecules using carbon dioxide as a carbon source. What is the electron source that helps reduce carbon dioxide to sugars and other organic molecules?
NADPH
182
A medical scientist is designing an experiment to test a new anti-cancer drug that she hypothesizes will greatly reduce and possibly eliminate adverse side effects compared to the current treatment. If this experiment is to be set up correctly, she must
Divide the patients into two groups and give one group the new drug and the other group a placebo (or sugar pill)
183
Replication moves outward from the origin in ________ direction(s) and is said to be ________.
both, bidirectional
184
An explanation of a fundamental principle developed through extensive and reproducible observations is a
Theory
185
About twenty-five of the 92 natural elements are known to be essential to life. Which 4 of these 25 elements make up approximately 96 percent of living matter?
carbon, hydrogen, nitrogen, oxygen
186
Although there are three different types of fibers that make up the cytoskeleton, all have the same function inside the cell.
false
187
You've found an unknown substance that you've designated Substance X. This substance dissolves in water. Based on this fact, you know that the majority of the bonds in the molecules that make up Substance X can NOT be.
non-polar covalent
188
Bipasha is studying a new drug, Calcigro, that is suspected to improve bone density. The drug has made it through animal testing and into human trials. Two groups of females have been matched for age, race and health status. Group A is given a pill containing starch and 1000 mg of Calcigro while Group B is given a pill containing starch only. Both groups are following a diet regimen with an intake of 1000 mg of calcium daily.
What is the independent variable?
Contents of the pill
189
What are the molecules that go into (are the “inputs” for) the electron transport chain and chemiosmosis?
ADP + P
Oxygen
Electrons from FADH2
Electrons from NADH
190
What are the molecules that go into (are the “inputs” for) glycolysis?
Glucose
ADP + P
NAD+
191
What are the molecules that go into (are the “inputs” for) the Citric Acid Cycle?
NAD+
Acetyl CoA
ADP (or GDP) + P
FAD+
192
What statements pertaining to lipid-soluble cells signals are true?
Lipid-soluble signals usually bind to an internal receptor in the cytosol to cause an effect.
Lipid-soluble signals can usually be transported directly through the cellular membrane.
193
Semiconservative replication involves a template. What is the template?
one strand of the DNA molecule
194
In an analysis of the nucleotide composition of DNA, which of the following will be found?
A + C = G + T
195
Which of the following reactions is the correct description of the beginning of the Citric Acid (Kreb’s) Cycle?
Acetyl CoA + oxaloacetate → citrate
196
Where does Glycolosis take place in eukaryotic cells?
Cytoplasm (Cytosol)
197
What are the final products (or “outputs”) of the Citric Acid Cycle?
CO2
ATP
FADH2
NADH
198
What are the final products (or “outputs”) of the Electron Transport Chain and Chemiosmosis?
Water
ATP
FAD+
NAD+
199
What are the final products (or “outputs”) of glycolysis?
ATP
NADH
Pyruvate
200
Dihydrofolate reductase catalyzes the reaction that breaks down folic acid into cofactors to create nucleotides. The reaction is inhibited by methotrexate (which resembles folic acid, but cannot be catalyzed by dihydrofolate reductase). Increasing the ratio of folic acid to methotrexate reduces the inhibitory effect of methotrexate.
Dihydrofolate reductase is the enzyme and folic acid is the substrate.
201
What will be able to cross the phospholipid bilayer of a cell membrane without the assistance of a membrane protein?
A small nonpolar molecule (e.g. CO2)
202
Which polysaccharide has the main function of energy storage in plants?
Starch
203
A cell, after undergoing glycolysis, takes the products from these reactions and immediately begins alcoholic fermentation. Which of the following cell types could achieve the above scenario?
A yeast cell
| A prokaryotic cell
204
The DNA strand growing toward the replication fork grows ______ in a 5'—>3' direction as the replication fork advances and is called the ________.
continuously, leading strand
205
What are the “outputs”, or products, of the light-dependent reactions of photosynthesis?
NADPH
Oxygen
ATP
206
What are the final products (or “outputs”) of the light-dependent reactions of photosynthesis?
O2
ATP
NADPH
207
How are the light-dependent and light-independent reactions of photosynthesis related?
The products of light-dependent reactions are used in light-independent reactions.
208
The electron carrier NAD+ undergoes _____ to form ____.
reduction
| NADH
209
Chitin is a major component of the ________.
exoskeleton of insects
210
What are the differences between DNA and RNA?
- The sugars differ between the nucleotides found in each.
- One is most often double-stranded, while the other is usually single-stranded.
- There are differences in the nitrogenous bases found in the nucleotides of each
211
What organelle contains enzymes for the synthesis of lipids?
Smooth ER
212
Which of the following characteristics, structures, or processes is common to bacteria and viruses?
genetic material composed of nucleic acid
213
Put the following steps of DNA replication in chronological order.
- Hydrogen bonds between base pairs of antiparallel strands are broken
- Single-stranded binding proteins attach to DNA strands
- Primase binds to the site of origin
- An RNA primer is created
- DNA polymerase binds to the template strand
214
Bonds between two atoms that are equally electronegative are ________
nonpolar covalent bonds
215
What are the molecules that go into (are the “inputs” for) pyruvate processing?
NAD+
| Pyruvate
216
Which of the following is TRUE of osmosis?
In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration
217
A cell, after undergoing glycolysis, takes the products from these reactions and immediately shuttles them to the mitochondria for processing. Which of the following cell types could achieve the above scenario?
A human muscle cell
| A prokaryotic cell
218
In mitochondria, chemiosmosis moves protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis moves protons from the ________.
stroma to the thylakoid space
219
Cellulose is ________.
a major structural component of plant cell walls
220
Bacteria are grown in a medium containing 15NH4Cl for a number of generations so that all of the DNA is made of fully "heavy" DNA. The bacteria are moved to a new medium and grown in 14NH4Cl so that all new DNA will be "light". If replication were dispersive, what would the DNA look like after one generation time.
Each strand is made of a mixture of "heavy" and "light" DNA with each strand being about 50% "light".
221
What statement best represents the relationships between the light reactions and the Calvin cycle?
The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, P, and NADP+ to the light reactions.
222
A bacterial cell suddenly stops creating protein, even though the DNA is still present and in working order. Which organelle’s malfunction would be responsible for this result?
Ribosomes
