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Flashcards in Chapter 5 Deck (54):
1

Anabolism

*

Production of new cellular components with the utilization of energy

2

Catabolism

*

Breakdown of food materials with the release of energy

3

Denaturation

*

a loss of natural shape-

usually applied to proteins

results in a loss of protein function

4

Aerobic Respiration

*

oxidation of glucose that employs molecular oxygen as the final electron/hydrogen acceptor

5

Anaerobic Respiration

*

oxidation of glucose that employs an inorganic molecule other than molecular oxygen as the final hydrogen acceptor

6

Electron Transport Chain

*

The stage of aerobic respiration that produces the most ATP and utilizes oxidative phosphorylation.

7

Fermentation

*

oxidation that takes place in the absence of molecular oxygen and uses an organic molecule as the final electron/hydrogen acceptor

8

How do enzymes speed up chemical reactions?

(2 parts)

*

 

1. Enzymes combine with substate to form an enzyme-substrate complex.

 

2. The combing of the enzyme and substrate lowers the activation energy of the reaction

9

List three differences between competitive and noncompetitive inhibitors.

(3 parts)

*

1. The binding site on the enzyme.

competitive - active site

noncompetitive - allosteric site

 

2. Effect on rate of reaction.

competitive - slows the reaction

noncompetitive - stops the reaction

 

3. Effect on the enzyme.

competitive - no effect on the shape of the active site

noncompetitive - changes the shape of the active site

10

List 3 conditions that can denature a protein.

(3 parts)

*

1. High temperature (not low temperature).

2. Acidic or basic pH (both can denature).

3. High salt concentrations.

11

Describe three differences between enzyme inhibition and denaturing.

*

1. Inhibitors are a result of feedback inhibition, excess product.  Denaturing agents are usually physical agents from the environment.

 

2. The effect of inhibitors are reversable.  Denaturing is not reversable

 

3. Some inhibitors slow enzyme activity.  Denaturing always stops activity. 

12

Which method of oxidizing glucose is the most efficient?

Which is the least efficient?

*

Aerobic respiration is the most efficient because it produces 36 or 38 ATP from one molecule of glucose.

 

Fermentation is the least efficient because it produces only 2 ATP from a molecule of glucose. 

13

Describe how ATP links catabolic and anabolic reactions in living cells.

*

1. Catabolic reactions break down large, complex molecules and release energy to make ATP (phosphorylation).

 

2. Anabolic reactions are building reactions that require energy.  The energy to run anabolic reactions comes from breaking ATP (dephosphorylation).

14

What are the two parts of a holoezyne?

*

1. A coenzyme or a cofactor

 

2. An apoenzyme

15

What are the final electron acceptors for the three methods of oxidizing glucose discussed in class.

*

1. Oxygen is the final electron acceptor for aerobic respiraton.

2. An inorganic molecule other than oxygen is the final electron acceptor for anaerobic respiration.

 

3. An organic molecule is the final electron acceptor for fermentation.

16

What is the difference between a coenzyme and a cofactor?

*

A coenzyme is an organic molecule that combines with an enzyme to complete the active site and a cofactor is an inorganic molecule that combines with an enzyme to complete the active site.

17

What are the three general characteristics of an enzyme?

*

1. Enzymes speed up metabolic reactions.

2. Enzymes do not become part of the product.

3. Enzymes are fragile and easily denatured because they are proteins.

18

What are the three steps of an enzymatic reaction?

*

1. The substrate or substrates bind to the active site of the enzyme.

2. The enzyme and substrate become one molecule, an enzyme-substrte complex for a split second.

3. The substrate is change to product and released by the enzyme.

19

What is the relationship between an enzyme and its substrate?

*

The substrate has the exact shape that allows it to bind to the active site of an enzyme.

20

 

 

Holoenzyme

*

 

An active enayme wtih functional active site.

Consist of an apoenzyme and cofactor or coenzyme.

21

 

 

Krebs cycle

*

  • A series of reactions in which a large amount of potential chemical energy is released (2 ATP).
  • Completed in Aerobic respiration.
  • Is not completed in Anaerobic respiration due to lack of oxygen.
  • Is not present during Fermentation.

 

22

 

 

Lactic Acid Fermentation

*

 

 

A catabolic process, beginning with glycolysis, that produces lactic acid to reoxidize NADH.

Occurs in animals and only produces 2 ATP.

23

 

 

Noncompetitive Inhibition

*

  • An inhibitor binds to the allosteric site, causing the active site of the enzyme to change shape.
  • Therefore, the substrate cannot fit.
  • This temporarily denatures the enzyme which stops the reaction.

24

 

 

Substrate

*

 

 

Any substance that combines with and is changed by an enzyme.

 

25

Which of the following compounds is NOT an enzyme?

A) Dehydrogenase      C) Cellulase     E) Coenzyme A 
B) β-galactosidase      D) Sucrase 
 

 E) Coenzyme A 

 

26

2)  Which of the following statements about anaerobic respiration is false? 
A) It involves glycolysis only.   
D) It involves the Krebs cycle. 
B) It involves the reduction of nitrate.   
E) It generates ATP. 
C) It requires cytochromes.  

A) It involves glycolysis only.  

27

A strictly fermentative bacterium produces energy 


A) By glycolysis only.       
D) By aerobic respiration only. 
B) By fermentation or aerobic respiration.    
E) Only in the absence of oxygen. 
C) Only in the presence of oxygen. 
 

A) By glycolysis only.  

28

5) Assume you are working for a chemical company and are responsible for growing a yeast culture that produces ethanol. The yeasts are growing well on the maltose medium but are not producing alcohol. What is the most likely explanation? 
A) The maltose is toxic.   
D) O2 is in the medium.
B) Not enough protein is provided.  
E) The temperature is too low. 
C) The temperature is too high.  

D) O2 is in the medium

29

Catabolic reactions------> __________

EXERGONIC 

30

Anabolic reactions-----> __________

Endergonic 

31

When a poison binds to an active site it completely shuts down the enzyme ______

A. Permanently 

B. Temporarily 

 

Permanently 

32

In Aerobic Respiration

Glycolysis yields ____ATP

Krebs cycle ____ATP

Electron transport ____ATP

TOTAL ____ ATP 

 GLYCOLYSIS 2

 KREBS CYCLE 2

ETC  24

 TOTAL 38

33

Name two fermentation products

Total ATP yield

Lactic Acid & alcohol

2 ATP

34

AM: A strictly fermentative bacterium produces energy 
A) By glycolysis only.        D) By aerobic respiration only. 
B) By fermentation or aerobic respiration.     E) Only in the absence of oxygen. 
C) Only in the presence of oxygen. 

 

A)  Organisms that only ferment do not undergo the Krebs cycle or the electron transport chain.

35

AM: Assume you are working for a chemical company and are responsible for growing a yeast culture that produces ethanol. The yeasts are growing well on the maltose medium but are not producing alcohol. What is the most likely explanation? 
A) The maltose is toxic.    D) O2 is in the medium.
B) Not enough protein is provided.   E) The temperature is too low. 
C) The temperature is too high. 

 

D)  Facultative anaerobes with use oxygen if it is present which does not produce alcohol.

36

            Noncompetive Inhibitor                                                 

Binds to the allosteric site instead of the active site.

37

whay does a Enzymes end with

-ase

38

fermentation

does not undergo the krebs cycle or the ETC

39

why does the substrate bind to the active site

Because it has the right shape

40

Each enzyme has only

one active site

41

RM

Gycolysis is the first stage in _______ catabolism.

CARBOHYDRATE

42

RM

Oxidation ________ electrons while reduction ________ electrons.

REMOVES

GAINS

43

JLW: What are all the chemical reactions with a living organism called? 

metabolism

44

JLW: Which of the following compounds has the greatest amount of energy for a cell?   

A. CO2

B. O2

C. ATP

D. Glucose

E. lactic acid

D. Glucose

45

JLW: The enzyme-regulated energy-requiring reactions are involved mostly in?

A.catabolism

B. anabolism

C. photosynthesis

D. oxidation

B. Anabolism

46

JLW: Apoenzymes are inactive by themselves and must be activated by?

A. cofactors

B. atp

C. holoenzymes

D. substrates

a. cofactors

47

JLW: Energy is released during a cell's?

A. reduction of glucose

B. decarboxylation of glucose

C. oxidation of glucose

D. phosphorylation of glucose

C. Oxidation of glucose

48

Competitive inhibitors have what effect on enzymatic activity?

a) They stop activity.

b) They slow activity.

c) They increase activity.

d) They have no effect.

b) they slow activity

49

Feedback inhibitors usually block which enzyme in a chain of reactions and enzymes?

a) first

b) second

c) last

d) equal chance among each

a) the first enzyme

50

Which reactions have an exergonic result?                    MP

Catabolic                        MP

51

Which for of respiration results in the production of only 2 ATP?           MP

Fermentation                             MP

52

53

G.L. Name the factor that will not denature the enzyme:

 

a) high pH (alkaline)

b) low pH (acidic)

c) high temperature

d) low temperature

e) osmotic pressure

 

 

 

G.L. d) low temperature

54

 

G.L. What are the steps of fermentation?

 

a) glycolysis and incomplete Kreb's cycle

b) glycolysis only

c) glycolysis, Kreb's cycle, electron transport chain.

d) doesn't have steps, because it doesn't produce ATP

 

 

G.L. b) glycolysis only