biol215 unit 3

A freshwater protozoan was placed in solution X and observed to open and close its contractile vacuoles at a rate of 10 contractions per minute. The same protozoan was then placed in solution Y and observed to open and close its contractile vacuoles at a rate of 5 contractions per minute.

True/False: Solution X is hypertonic relative to Solution Y

True

Which of the following best describes how a plant cell gets the energy it needs for extracellular processes, such as its own growth and development?

A. Most ATP comes from digestion of organic matter absorbed by roots, some comes from chloroplasts.

B. The organic molecules made by photosynthesis can be used by respiration to make ATP.

C. In the light, ATP comes from the chloroplast, in the dark, from mitochondria.

D. ATP is transported to cells that lack chloroplasts (roots, stems, etc)

E. The chloroplasts provide all ATP needed by the plant.

B

A young dog never had much energy. His veterinarian discovers that the dog's mitochondria can use only fatty acids and amino acids for respiration, and his cells produce more lactate than normal. Which of the following best explains the dog's condition?

A. His cells have a defective electron transport chain, so glucose goes to lactate instead of to acetyl CoA

B. His cells contain something that inhibits oxygen use in his mitochondria

C. His mitochondria lack the transport protein that moves pyruvate across the outer mitochondrial membrane

D. His cells cannot move NADH from glycolysis into the mitochondria

E. His cells lack the enzyme in glycolysis that forms pyruvate

C

True/False: Increase levels of G-6-P in the cytoplasm would indicae the energy needs of the cell ARE MET, thus initiating glycogensis.

True

A particular strain of mice called Cleaver mice have difficulty maintaining posture and moving normally. This defect has been attributed to a mutant channel protein that allows potassium ions to easily pass across the plama membrane.

True/False: Increase the potassium ion permeability will result in a more positive membrane potential (Vm) of cells in Cleaver mice.

A. True

B. False - there will be no change in Vm

C. False - The Vm will become more negative

C

True/False: Aerobic respiration in plant cells takes place in the chloroplast

A. True

B. False, because aerobic respiration in plants does not take place in the chloroplast

C. False, because plants do not carry out aerobic respiration

B

The catabolism of two glucose molecules would result in the release of ____ molecules of CO2 from the Krebs cycle

A. 2

B. 3

C. 4

D. 8

E. 12

D

Which of the following best describes the basic function of fermentation?

A. further oxidation of the products of glycolysis

B. production of oxygen for use in the electron transport chain

C. catabolism of ethanol or lactic aid for energy transfer

D. oxidation of NADH

E. more than one of the above

D

Which process is catalyzed by the Rubisco enzyme?

A. combining acetyl from acetyl-CoA with oxaloacetate

B. splitting water to release oxygen

C. "fixation" of CO2 to the acceptor molecule ribulose-1,5-bisphosphate

D. reduction of Calvin cycle intermediates using NADPH

E. phosphorylation of triose phosphate to regenerate rubulose-1,5-bisphosphate

C

Why is oxygen necessary for aerobic respiration?

A. Is it directly involved in the phosphorylation of ADP to form ATP

B. It is an electron acceptor in the citric acid cycle

C. it is needed for glycolysis

D. it accepts electrons at the end of the electron transport chain

E. none of the above. oxygen is not necessary for aerobic respiration

D

During the aerobic respiration pathway, which of the following best summarizes the sequence of electron travel?

A. glucose --> NAD+/NADH --> pyruvate --> ATP --> oxygen

B. glucose --> NAD+/NADH --> Krebs Cycle --> ATP

C. glucose --> NAD+/NADH --> Krebs Cycle --> electron transport chain --> ATP

D. glucose --> NAD+/NADH --> electron transport chain --> oxygen

E. glucose --> NAD+/NADH --> electron transport chain --> oxygen --> ATP

D

True/False: During oxygenic photosynthesis, H2O is reduced and CO2 is oxidized.

False

Fatty acid metabolism leads directly to the Krebs cycle, this means that the fatty acids must first be transported into which cellular location?

A. ER lumen

B. intermembrane space of the mitochondria

C. mitochondrial matrix

D. stroma

E. thylakoid lumen

C

Which of the following statements correctly describes NAD+?

A. It is oxidized by the action of hydrogenases

B. it is the oxidized form of NADH

C. it can donate electrons for use in oxidative phosphorylation

D. it has more chemical energy than NADH

E. more than one of the above is true

B

True/False: Both phosphoglycerides and sphingolipids use glycerol as a backbone molecule

False

Which of the following best describes the main function of aerobic respiration?

A. breakdown of glucose to carbon dioxide and water products

B. Catabolism of sugats into smaller products

C. breaking down ATP, so that ADP and Pi can be reused by the cell

D. producing complex moleules from smaller molecular building blocks

E. transforming the energy to glucose into a chemical form that cells can use for work

E

Warburg effect refer to the fact that concerous cells exhibit higher than normal rates of _______

A. aerobic respiration

B. glycogenesis

C. oxidative phosphorylation

D. oxidative decarboxylation

E. glycolysis

E

18

18

What happens to the energy released as electrons are transferred through the electron transoirt system from photosystem II to Cytb6/f?

A. it is used to phosphorylate NAD+ to NADP+

B. it is released as heat and fluorescence due to the return of these electrons to their ground state

C. it is used to establish and maintain a proton gradient

D. it excites electrons in the reaction center of photosystem I

E. more than one of the aboe

C

The products of glycolysis include ____

A. acetyl CoA and FADH2

B. pyruvate, CO2, NADH, ATP

C. CO2, NADH, and ATP

D. CO2 and NADH

E. pyruvate, NADH, and ATP

E

True/False: The evolution of aerobic respiration led to increased oxygen levels of Earth's atmosphere

False

To ensure regulation, certain Calvin cycle enzymes are activated when they are _____. Others are activated by an increase in ______.

A. oxidized;pH

B. reduced;pH

C. oxidized;[H+]

D. reduced; [H+]

B

In oxidative phosphorylation, what is the most direct source of energy that is used to convert ADP and inorganic phosphate to ATP?

A. the thermodynamically favorable flow of electrons through the electron transport chain

B. energy released from diffusion of protons from the intermemembrane space to the matrix through ATP synthase

C. the thermodynamically favorable transfer of phosphate from glycolysis and teh citric acid cycle intermediate molecules of ADP

D. energy released from ATP hydrolysis

E. no external source of energy is required because the reaction is exergonic

B

Regarding fatty acid metabolism, which of the following will occur when energy is needed by the cell?

A. production of acetyl-CoA, which decreases the rate of the citric acid cycle

B. production of acetyl-CoA, which increases the rate of the citric acid cycle

C. production of Glucose-1-phosphate, which increases the rate of the citric acid cycle

D. production of Glucose-6-phosphate, which decreases the rate of the citric acid cycle

E. production of Glucose-6-phosphate, which increases the rate of the citric acid cycle

B

Comparing the mitochondrion and the chloroplast, whcih chloroplast compartment is most like the intermembrane space in the mitochondrion, in terms of function?

A. inner membrane

B stroma

C. matrix

D. thylakoid lumen

E. outer membrane

D

True/False: During glycolysis, G3P is isomerized to form DHAP, which is used in the next step

False

During photophosphorylation, ATP synthesis takes place in the _____.

A. stroma

B. thylakoid lumen

C. matrix

D. intermembrane space

E. none of the above, photophosphorylation does not involve ATP synthesis

A

Human muscle cells function as facultative aerobes. Which of the following processes can be carried out in these cells?

A. glycolysis only

B. only glycolysis and fermentation

C. only citric acid cycle and electron transport

D. fermentation only

E. glycolysis, citric acid cycle, electron transport and fermentation

E

When a photoexcited pigment fluoresces, is the wavelength of the fluorescent light longer or shorter than the wavelength of the absorbed light?

A. longer

B. shorter

C. neither, the wavelengths are the same

A

Increased concentrations of Acetyl CoA in a cell will ______ regulate glycolysis.

A. negatively

B. positively

C. none of the above. accumulation of coenzyme A will have no effect on glycolysis

A

Which of the following would be present in the cell of an aerobic organism under hypoxic conditions?

A. excess of ATP

B. excess of NADH

C. excess of NAD+

D. increased production of proteins

E. increased production of CO2

B

The proper sequence of the events during glycolysis is:

A. cleavage, glucose priming, ATP generation, oxidation

B. ATP generation, oxidation, glucose priming, cleavage

C. glucose priming, oxidation, cleavage, ATP generation

D. glucose priming, cleavage, oxidation, ATP generation

E. oxidation, cleavage, ATP generation, glucose priming

D

Comparing NADH and Complex I of the electron transport chian (ETC) in the mitochondrion, which molecule is more electronegative?

A. NADH

B. Complex I of the ETC

C. They have the same electronegativity

B

Following the excitation and transfer of electrons from the reaction center on Photosystem II, electrons are replaced by

A. CO2

B. O2

C. H2O

D. Photosystem I

E. NADPH

C

During aerobic respiration, _________.

A. CO2 is reduced and O2 is oxidized

B. O2 is reduced and CO2 is oxidized

C. O2 is oxidized and H2O is reduced

D. C6H12O6 is reduced and CO2 is oxidized

E. C6H12O6 is oxidized and O2 is reduced

E

A 12 carbon saturated fatty acid, lauric acid, is found naturally in cocnt and palm kernel oils. When catabolized, lauric acid requires _____ rounds of beta oxidation pathway, and produces ______ molecules of acetyl CoA

A. 5;6

B. 6;6

C. 7;6

D. 6;7

E. 7;8

A

The process of _________ would be activated when glucose is in excess and the cell does not ened additional energy in the form of ATP

A. glycogenolysis

B. glycolysis

C. gluconeogenesis

D. glycogenesis

E. glycosylation

D

As electrons move through the electron transport chain, protons are actively driven into the _________, resulting in a(n) __________ in the pH of the matrix.

A. intermembrane space;increase

B. matrix;decrease

C. matrix;increase

D. intermembrane space;decrease

E. more than one of the above

A

Yogurt production involves all of the following EXCEPT ________.

A. aerobic respiration

B. decreasing pH of the milk

C. glycolysis

D. lactate fermentation

E. all of the above are involved in yogurt production

A

The carbon that enters the Calvin cycle is ________ to form triose phosphates.

A. reduced by ATP

B. reduced by NADPH

C. oxidized by NADPH

D. reduced and phosphorylated by ATP

E. reduced and phosphorylated by NADPH

B

In glycolysis, glucose is _____, resulting in two pyruvate molecules.

A. reduced during an anabolic pathway

B. reduced during a catabolic pathway

C. oxidized during a catabolic pathway

D. oxidized during an anabolic pathway

E. synthesized and reduced

C

Which targetting pathway would a peroxisomal enzyme have gone through in order to carry out its role inside the peroxisome?

A. post translational

B. cytoplasmic (default)

C. co translational

D. could be any of the above, depending on the cell typ e

E. not enough information given

A

Most of the energy that the cell extracts from the metabolism of glucose is _____.

A. stored in the ATP that was formed by glycolysis and teh citric acid cycle.

B. stored in NADH and FADH2

C. stored in teh carbon dioxide and water molecules released by these processes

D. lost as heat

E. stored in pyruvate

B

Some bacteria can carry out anoxygenic photosynthesis, using H2S as an electron donor. Assuming that the process is otherwise similar to oxygenic photosynthesis, which of the following could represent the overall reaction? (equations are not balanced)

A. CO2+H2S --> C6H12O6 + SO2

B. CO2+H2S --> C6H12O6 + S

C. CO2+H2S --> C6H12O6 + O2

D. CO2+H2S --> C6H12S6 + O2

B

During which stage of oxygenic photosynthesis is O2 produced?

A. ATP synthesis

B. Calvin Cycle

C. Krebs Cycle

D. Electron Transport Chain

E. none of the above. oxygen is consumed, not produced, during oxygenic photosynthesis

D

The synthesis of ATP by oxidative phosphorylation is based on several lines of experimental evidence. Which of the following statements regarding experimental observations does NOT support the oxidative phosphorylation model.

A. electron transport decreases the pH of the intermembrane space

B. uncoupling agents that abolish the proton gradient also abolish ATP synthesis

C. oxidative phosphorylation requires a membrane enclosed compartment

D. the proton gradient generated by electron transport has enough energy to drive ATP synthesis

E. all of the above support the oxidative phosphorylation model

E

True/False: Dogs are considered autotrophs since they can 'eat for themselves'

False

A newly discovered organelle is found to produce or use up the following molecules under experimental conditions. Based on this analysis, which metabolic process is taking place in this organelle?

Produce: ADP+Pi, 3 carbon sugars, NADP+

Use up: ATP, CO2, NADPH

No change: O2

A. Calvin Cycle

B. oxidative phosphorylation

C. glycolysis

D. Krebs cycle

E. light reactions

A

Which of the follow is (are) TRUE of the Cori cycle?

A. ATP is produced in the liver for use in muscle cells?

B. Gluconeogenesis occurs in muscle cells

C. Lactate is converted into glucose in the liver

D. Glycogenolysis in the liver occurs to release free glucose

E. More than one of the above is true

C

During photosynthesis, protons are actively driven into the __________, causing the pH of stroma to ____________.

A. thylakoid lumen;increase

B. thylakoid lumen;decrease

C. stroma;increase

D. stroma;decrease

E. matrix;decrease

A