Question 1

Why are alcoholic beverages often made in airtight containers?

Accepted Answer

The alcohol in these beverages is produced by fermentation,which only occurs in the absence of oxygen.

Question 2

You isolate the enzyme that synthesizes folic acid in bacteria and conduct some enzyme kinetics experiments.You find,not surprisingly,that sulfa drugs inhibit the enzyme's activity.What happens to the Vmax and KM of this enzyme when it is treated with sulfa drugs? Why do sulfa drugs have no effect on human metabolism?

Accepted Answer

Since the sulfa drugs are competitive inhibitors,the V_max should stay the same and the K_M should increase.Sulfa drugs work by acting as a competitive inhibitor of an enzyme that converts p-aminobenzoic acid (PABA)to the essential coenzyme folic acid.Since humans lack a folic-acid synthesizing enzyme,they must obtain this essential coenzyme in their diet and,consequently,sulfa drugs have no effect on human metabolism.

Question 3

The energy stored in ATP is converted to mechanical energy that moves organelles around within the cell.This is an example of __________.

Accepted Answer

A) being exothermic 
B) being endothermic 
C) energy transduction 
D) polymerization 
E) catheterization 
A) being exothermic 
B) being endothermic 
C) energy transduction 
D) polymerization 
E) catheterization C

Question 4

Given the equation $\Delta$G = $\Delta$H - T$\Delta$S,which set of conditions would result in a reaction that is unambiguously nonspontaneous?

Accepted Answer

A) entropy decreases and the reaction is endothermic 
B) entropy increases and the reaction is exothermic 
C) entropy stays the same and there is no change in enthalpy 
D) entropy decreases and the reaction is exothermic 
E) entropy increases and the reaction is endothermic 
A) entropy decreases and the reaction is endothermic 
B) entropy increases and the reaction is exothermic 
C) entropy stays the same and there is no change in enthalpy 
D) entropy decreases and the reaction is exothermic 
E) entropy increases and the reaction is endothermic

Question 5

There have been two new classes of antibiotics developed and approved since 1963.One of these antibiotics acts specifically on bacterial ribosomes.What is it? Another new group of antibiotics is the cyclic lipopeptides.What is a representative of this group and how does this group of antibiotics work?

Accepted Answer

The antibiotic linezolid (brand name Zyv

Question 6

What is the effect of a competitive inhibitor on an enzyme-mediated reaction?

Accepted Answer

A) Vmax stays the same,KM decreases 
B) Vmax decreases,KM is unchanged 
C) Vmax increases,KM is unchanged 
D) Vmax stays the same,KM is unchanged 
E) Vmax stays the same,KM increases 
A) Vmax stays the same,KM decreases 
B) Vmax decreases,KM is unchanged 
C) Vmax increases,KM is unchanged 
D) Vmax stays the same,KM is unchanged 
E) Vmax stays the same,KM increases

Question 7

What kind of organism reaches equilibrium?

Accepted Answer

A) one that is actively metabolizing 
B) one with a low metabolic rate 
C) a dead organism 
D) a eukaryote 
E) a prokaryote 
A) one that is actively metabolizing 
B) one with a low metabolic rate 
C) a dead organism 
D) a eukaryote 
E) a prokaryote

Question 8

Metabolic pathways that make available raw materials from which other molecules can be synthesized and that provide chemical energy required for many cell activities are known as ______.

Accepted Answer

A) anabolism 
B) catabolism 
C) manabolism 
D) allosterism 
E) anabolism and catabolism 
A) anabolism 
B) catabolism 
C) manabolism 
D) allosterism 
E) anabolism and catabolism

Question 9

How are new compounds typically screened for their effectiveness as antibiotics?

Accepted Answer

A compound is tested for its ability to

Question 10

What kind of enzyme adds phosphate groups to enzymes for the purpose of activating or deactivating them?

Accepted Answer

A) phosphatases 
B) protein kinases 
C) flippases 
D) glycosyltransferases 
E) carboxypeptidase 
A) phosphatases 
B) protein kinases 
C) flippases 
D) glycosyltransferases 
E) carboxypeptidase

Question 11

If mice are maintained on very strict diets with reduced caloric intake,what happens to their life span as compared to littermates fed diets with normal caloric content? What is a possible explanation for the effect of this diet on these animals?

Accepted Answer

The mice on restricted calorie diets liv

Question 12

Proteins are dynamic molecules that are capable of ________ motion that can have important functional relevance.The existence of this type of motion has suggested that enzymes are capable - even in the absence of substrate - of many of the same movements that can be detected during their catalytic cycle.

Accepted Answer

A) extrinsic 
B) intrinsic 
C) instant 
D) built-in 
E) intrinsic and built-in 
A) extrinsic 
B) intrinsic 
C) instant 
D) built-in 
E) intrinsic and built-in

Question 13

Why has the pharmaceutical industry drastically cut resources devoted to the development of new antibiotics?

Accepted Answer

The decrease in the pharmaceutical indus

Question 14

Below is a segment of a cell's collection of biochemical pathways.M is a product of one series of these reactions.It is also a regulatory molecule.Look at the pathway below and indicate the position(s)at which M is most likely to act as a feedback inhibitor when its concentration gets too high.

Accepted Answer

M will be most likely to act as a feedba

Question 15

What strategies are employed to combat the ability of the AIDS (HIV)virus to develop drug-resistant variants?

Accepted Answer

One strategy employed is having patients

Question 16

An enzyme has a KM of 20 µM and a Vmax of 50 mmoles of product/minute/µg of enzyme.After exposure to an inhibitor and analysis on a Lineweaver - Burk plot the following values are obtained: -1/ KM = - 0.05 liters/µmole and 1/ Vmax = 0.04 (mmoles of product/minute/µg of enzyme)-1.What kind of inhibitor was used in the experiment?

Accepted Answer

Since the K_M has rema

Question 17

Which reaction below might be a suitable coupled reaction for the reaction A + B  C + D ($\Delta$G = -8.7 kcal/mole)?

Accepted Answer

A) E + F  G + H ($\Delta$G = -5.4 kcal/mole) 
B) B + F  G + H ($\Delta$G = -5.4 kcal/mole) 
C) C + F  G + H ($\Delta$G = +8.3 kcal/mole) 
D) C + F  G + H ($\Delta$G = +9.7 kcal/mole) 
E) A + F  G + H ($\Delta$G = +10.2 kcal/mole) 
A) E + F  G + H ($\Delta$G = -5.4 kcal/mole) 
B) B + F  G + H ($\Delta$G = -5.4 kcal/mole) 
C) C + F  G + H ($\Delta$G = +8.3 kcal/mole) 
D) C + F  G + H ($\Delta$G = +9.7 kcal/mole) 
E) A + F  G + H ($\Delta$G = +10.2 kcal/mole)

Question 18

Penicillin is an irreversible inhibitor of the transpeptidases,enzymes that cross-link components of the bacterial cell wall.The cell wall is thus fragile and the bacteria die.Penicillin and its derivatives are structural analogs of the natural substrates of these enzymes.Why doesn't penicillin normally kill humans,unless a severe allergic reaction (anaphylaxis)develops? How does penicillin inhibit transpeptidase?

Accepted Answer

Humans don't have cell walls and transpe

Question 19

What appears to be the effect of reduced calorie intake on rhesus monkeys?

Accepted Answer

The rhesus monkeys have lower blood leve

Question 20

Enzymes work by ___________.

Accepted Answer

A) raising the activation energy of a reaction and thus speeding up the reaction. 
B) lowering the activation energy of a reaction and thus speeding up the reaction. 
C) raising the$\Delta$G of a reaction and thus speeding up the reaction. 
D) lowering the $\Delta$G of a reaction and thus speeding up the reaction. 
E) changing the free energy of the products and speeding up the reaction. 
A) raising the activation energy of a reaction and thus speeding up the reaction. 
B) lowering the activation energy of a reaction and thus speeding up the reaction. 
C) raising the$\Delta$G of a reaction and thus speeding up the reaction. 
D) lowering the $\Delta$G of a reaction and thus speeding up the reaction. 
E) changing the free energy of the products and speeding up the reaction.

Why are alcoholic beverages often made in airtight containers?

The energy stored in ATP is converted to mechanical energy that moves organelles around within the cell.This is an example of __________.

Given the equation $\Delta$ G = $\Delta$ H - T $\Delta$ S,which set of conditions would result in a reaction that is unambiguously nonspontaneous?

What is the effect of a competitive inhibitor on an enzyme-mediated reaction?

What kind of organism reaches equilibrium?

Metabolic pathways that make available raw materials from which other molecules can be synthesized and that provide chemical energy required for many cell activities are known as ______.

How are new compounds typically screened for their effectiveness as antibiotics?

What kind of enzyme adds phosphate groups to enzymes for the purpose of activating or deactivating them?

If mice are maintained on very strict diets with reduced caloric intake,what happens to their life span as compared to littermates fed diets with normal caloric content? What is a possible explanation for the effect of this diet on these animals?

Why has the pharmaceutical industry drastically cut resources devoted to the development of new antibiotics?

Below is a segment of a cell's collection of biochemical pathways.M is a product of one series of these reactions.It is also a regulatory molecule.Look at the pathway below and indicate the position(s)at which M is most likely to act as a feedback inhibitor when its concentration gets too high.

What strategies are employed to combat the ability of the AIDS (HIV)virus to develop drug-resistant variants?

Which reaction below might be a suitable coupled reaction for the reaction A + B <-> C + D ( $\Delta$ G = -8.7 kcal/mole)?

What appears to be the effect of reduced calorie intake on rhesus monkeys?

Enzymes work by ___________.

Introduction to the Study of Cell and Molecular Biology

The Chemical Basis of Life

The Structure and Function of the Plasma Membrane

Aerobic Respiration and the Mitochondrion

Photosynthesis and the Chloroplast

Interactions Between Cells and Their Environment

Cytoplasmic Membrane Systems: Structure, function, and Membrane Trafficking

The Cytoskeleton and Cell Motility

The Nature of the Gene and the Genome

Gene Expression: From Transcription to Translation

Control of Gene Expression

Dna Replication and Repair

Cellular Reproduction

Cell Signaling and Signal Transduction: Communication Between Cells

Cancer

The Immune Response

Techniques in Cell and Molecular Biology

Filters

Exam 3: Bioenergetics,enzymes and Metabolism

Why are alcoholic beverages often made in airtight containers?

The energy stored in ATP is converted to mechanical energy that moves organelles around within the cell.This is an example of __________.

Given the equation Δ\DeltaΔ G = Δ\DeltaΔ H - T Δ\DeltaΔ S,which set of conditions would result in a reaction that is unambiguously nonspontaneous?

What is the effect of a competitive inhibitor on an enzyme-mediated reaction?

What kind of organism reaches equilibrium?

Metabolic pathways that make available raw materials from which other molecules can be synthesized and that provide chemical energy required for many cell activities are known as ______.

How are new compounds typically screened for their effectiveness as antibiotics?

What kind of enzyme adds phosphate groups to enzymes for the purpose of activating or deactivating them?

If mice are maintained on very strict diets with reduced caloric intake,what happens to their life span as compared to littermates fed diets with normal caloric content? What is a possible explanation for the effect of this diet on these animals?

Why has the pharmaceutical industry drastically cut resources devoted to the development of new antibiotics?

Below is a segment of a cell's collection of biochemical pathways.M is a product of one series of these reactions.It is also a regulatory molecule.Look at the pathway below and indicate the position(s)at which M is most likely to act as a feedback inhibitor when its concentration gets too high.

What strategies are employed to combat the ability of the AIDS (HIV)virus to develop drug-resistant variants?

Which reaction below might be a suitable coupled reaction for the reaction A + B <-> C + D ( Δ\DeltaΔ G = -8.7 kcal/mole)?

What appears to be the effect of reduced calorie intake on rhesus monkeys?

Enzymes work by ___________.

Introduction to the Study of Cell and Molecular Biology

The Chemical Basis of Life

The Structure and Function of the Plasma Membrane

Aerobic Respiration and the Mitochondrion

Photosynthesis and the Chloroplast

Interactions Between Cells and Their Environment

Cytoplasmic Membrane Systems: Structure, function, and Membrane Trafficking

The Cytoskeleton and Cell Motility

The Nature of the Gene and the Genome

Gene Expression: From Transcription to Translation

Control of Gene Expression

Dna Replication and Repair

Cellular Reproduction

Cell Signaling and Signal Transduction: Communication Between Cells

Cancer

The Immune Response

Techniques in Cell and Molecular Biology

Filters

Given the equation $\Delta$ G = $\Delta$ H - T $\Delta$ S,which set of conditions would result in a reaction that is unambiguously nonspontaneous?

Which reaction below might be a suitable coupled reaction for the reaction A + B <-> C + D ( $\Delta$ G = -8.7 kcal/mole)?