Which of the following structures is involved with the movement of organelles within a cell?
Some proteins that are on the surface of mammalian cells contain carbohydrates. These proteins are synthesized by _______ and the sugars added in the _______.
the rough endoplasmic reticulum; Golgi apparatus
Plant cells do not have lysosomes. Which of the following structures likely fulfills the function of lysosomes in plant cell?
Which of the following organelles were probably once independent prokaryote organisms?
Mitochondria and chloroplasts
Which one of the following organelles is thought to have arisen from an endosymbiotic relationship with a prokaryote?
Which of the following is not a function of the plasma membrane of eukaryotes?
Adhering to other cells
Which of the following statements best describes what happens to the organelles of the pepper fruit cells as the fruit turns from green to red?
Chloroplasts become chromoplasts
Which of the following statements about the nucleus in animal cells is false?
The nucleus is the site of protein synthesis
Which of the following proteins powers both the movement of cilia and vesicles within a cell?
Cilia and eukaryotic flagella
must have a motor protein that uses the energy of ATP hydrolysis to power movement.
Which one of the processes listed below is not carried out by the smooth endoplasmic reticulum?
What would happen if a suspension of red blood cells in an isotonic NaCl solution was suddenly diluted with pure water by a factor of ten?
The cells would swell and lyse (burst).
In addition to the bilayer lipids and proteins, membranes may contain _______ in the form of _______ and _______.
carbohydrates; glycoproteins; glycolipids
Phospholipids spontaneously form bilayer structures, but oils form small droplets. Why do oils not form bilayers?
Oils do not have the polar head group that phospholipids have.
The specificity of ion channels for the ions they transport is
a result of the characteristics of the channel protein.
Which of the following molecules do you think would diffuse across a phospholipid bilayer fastest, assuming that there are no proteins associated with the bilayer. (Hint: keep in mind the nature of the interior of the bilayer).
is carried out by proteins that exhibit specificity for the molecules they transport.
A comparison of the properties of the plasma membrane to those of the membrane of lysosomes would reveal that
the two membranes have different proteins and lipids.
The sodium-potassium pump (or Na+-K+ pump)
results in the formation of a membrane potential across the plasma membrane.
A voltage difference is maintained across the plasma membrane. This voltage difference
arises because the sodium-potassium pump pumps 2 K+ in and 3 Na+ out during one catalytic cycle.
The biochemical reactions of biological membranes are carried out by _______ that may be either in contact with the interior of the bilayer (_______ to the membrane) or arranged on either side of the bilayer (_______ to the membrane).
proteins; integral; peripheral
Secondary active transport resembles transport by ion channels in that
both types of transport can involve the movement of Na+ across the plasma membrane
Which of the following statements about membrane proteins is false?
Hydrophilic regions of integral membrane proteins are in contact with the interior of the bilayer.
To be metabolized, glucose must be converted to glucose 6-phosphate. However, at equilibrium, a mixture of glucose and phosphate at concentrations that exist in cells would contain little glucose 6-phosphate. How do cells circumvent this problem?
ATP, not Pi, is used as the donor of the phosphoryl group, and, thus, the formation of glucose 6-phosphate is exergonic.
Suppose the reaction A ↔ B has a large, negative ΔG. In what direction, how far, and how fast will the reaction proceed?
From A to B; at equilibrium mostly B would be present; insufficient information is given to predict the rate of the reaction
A competitive inhibitor of an enzyme-catalyzed reaction
is usually structurally similar to the substrate
The synthesis of complex molecules is _______, whereas their degradation is _______. Synthesis occurs with _______ in entropy.
endergonic; exergonic; a decrease
Which of the following effectors of enzyme activity is least likely to be of importance in cells?
Which of the following parameters determines how far and in what direction a reaction will proceed?
Why is the statement, "ATP produces energy for life," wrong?
It is a violation of the first law of thermodynamics
In a reaction catalyzed by an enzyme
the enzyme does not affect the equilibrium constant for the reaction
The rate of a reaction catalyzed by an enzyme that has a single polypeptide chain
may be increased or decreased by temperature
Which of the following statements is (are) inconsistent with the first and second laws of thermodynamics?
a and c
Which of the following statements about ATP is false?
The phosphate bond energy of ATP is used to power catabolic metabolism
The idea that Eukaryotic cells are derived from prokaryotic cells living together in a mutualistic relationship is the
The ability of some materials to move through biological membranes more readily than others is called selective
4. The electric signal for contraction passes rapidly from one muscle cell to the next by way of
3. How does a competitive inhibitor inhibit binding of a substrate to an enzyme
b. It binds to the active site
5. Which statement about enzymes is true
c. They don't change the value of (delta) G of the reaction
2. Due to its ability to carry electrons and free energy, ____ is the most common electron carrier in cells
1. During the light reactions of photosynthesis the synthesis of_____ is coupled to the diffusion of protons.
5. During cyclic photophosphorylation, the energy to produce ATP is provided by
d. The redox reactions of the electron transport chain
The electron transport chain of mitochondria
contains cytochromes and proteins containing flavins (FAD
In the complete oxidation of glucose, 6 CO2 molecules are formed per glucose oxidized. Choose from the list below the correct numbers of CO2 molecules released by glycolysis (gly), the citric acid cycle (CAC), and pyruvate oxidation (pyr).
gly 0; CAC 4; pyr 2
The conversion of malate to oxaloacetate in the citric acid cycle takes place with the conversion of NAD+ to NADH. In this reaction, NAD+ is
Which of the compounds listed below link(s) glycolysis and the citric acid cycle to the mitochondrial electron transport chain?
Reagents, such as dinitrophenol, increase the permeability of the mitochondrial inner membrane to protons. The addition of dinitrophenol to a suspension of animal cells should
inhibit mitochondrial ATP synthesis
The synthesis of ATP from ADP and Pi is an _______ reaction. In mitochondria, ATP synthesis is driven by the flow of _______ down the concentration and electrical gradient established by _______.
endergonic; protons; electron transport
Which of the statements below about the citric acid cycle is false?
The cycle releases less energy than glycolysis
The mitochondrial electron transport chain
oxidizes the intermediate electron carriers, NADH and FADH2
Most of the ATP made during the complete oxidation of glucose to CO2 and water is
made by the mitochondrial ATP synthase
Which one of the following reactions is not an oxidation-reduction reaction?
R-CH=CH-CH3 + H2O ↔ RCH2-CH(OH)-CH3
Triglycerides are major energy storage molecules. Which statement about the complete oxidation of triglycerides to CO2 and water and the oxidation of glucose to two molecules of pyruvate is correct?
Only glucose oxidation uses the glycolytic pathway.
The mitochondrial ATP synthase
makes ATP at the expense of the proton gradient established by electron transport.
Cyanide inhibits the enzyme in the mitochondrial electron transport chain that reduces O2 to water. Suppose that you add cyanide to a suspension of muscle cells from a rat. Which statement given below is the most accurate with respect to the effects of cyanide on glucose catabolism?
The citric acid cycle would be inhibited, but glycolysis would not. Lactic acid accumulates.
A suspension of yeast supplied with glucose as its source of energy was transferred from an aerobic environment to an anaerobic one. What do you think would happen to the rate of glucose utilization and the rate of ethanol production after the transfer?
Both glucose usage and ethanol production would increase.
Which of the following is not a characteristic of C4 plants?
The first product of photosynthesis in C4 plants is 3PG
The _______ of photosynthesis is similar to the _______ of chlorophylls.
action spectrum; absorption spectrum
The concentration of CO2 in Earth's atmosphere has increased over the past 200 years. If this trend continues, as seems likely, what could happen to photosynthesis? Ignore global warming and assume that the content of oxygen in the atmosphere will not change.
The net yield C3 photosynthesis should increase; C4 photosynthesis should be unaffected.
In addition to driving the synthesis of ATP and the reduction of NADP+ to NADPH, light stimulates the Calvin cycle by _______ and _______.
increasing the pH of the stroma; reduction of some enzymes
Which statement given below best characterizes the properties of a photosystem?
A photosystem is a complex of pigments, proteins, and a reaction center chlorophyll
C4 plants have _______ rates of _______ than C3 plants because the ratio of the concentrations of CO2 to that of O2 is _______ in C4 plants.
lower; photorespiration; higher
If you were to grow a green plant in a lighted chamber in the presence of radioactive carbon dioxide for several days, which of the following types of compounds in the plant would be radioactive?
all the above
The immediate source of energy for ATP synthesis in chloroplasts is
the electrochemical proton gradient
Mesophyll cells of a leaf of a green plant
have metabolic pathways that are very similar to those in animal cells, except for photosynthesis
Which of the following statements about the role of chlorophyll in photosynthesis is false?
Most of the chlorophyll in a plant participates in an oxidation/reduction reaction
Which of the following statements about the light-independent reactions of photosynthesis is not correct?
The light-independent reactions operate in the dark
The major product of photosynthesis that is exported from the leaves to the rest of the plant is
Plants that carry out crassulacean acid metabolism (CAM) differ from C4 plants in that
their stomates are open at night