17: metabolism

Question 1

what is oxidized in oxidative phosphorylation?

Answer 1

NADH + H+ and FADH2

Question 2

What does “phosphorylation” in oxidative phosphorylation mean?

Answer 2

adding a phosphate group to ADP

Question 3

what is osmosis?

Answer 3

movement of water through a semipermeable membrane

Question 4

what gets made during glycolysis and is used for group translocation?

Answer 4

phosphoenol pyruvate

Question 5

What is glycolysis?

Answer 5

glucose getting broken down to pyruvate

Question 6

what is gained during aerobic glycolysis? Where are these products used later?

Answer 6

2 NADH + 2H+ and 2 ATP; the NADH + H+ can be used to generate ATP during oxidative phosphorylation

Question 7

If glycolysis is ___________ the pyruvate can be converted to ____________ and fed into the citric acid cycle to generate energy.

Answer 7

aerobic; acetylCoA

Question 8

In fermentation or anaerobic glycolysis, is pyruvate converted to acetylCoA?

Answer 8

no, no additional energy is obtained from pyruvate.

Question 9

if __________ is around, glycolysis is anaerobic

Answer 9

no oxygen

Question 10

what type of compound is the final electron acceptor in fermentation? what’s an example?

Answer 10

organic; pyruvate

Question 11

What component is needed to keep glycolysis going?

Answer 11

NAD+

Question 12

If glycolysis is anaerobic, pyruvate is ___________ and NADH + H+ gets _____________, this “wastes” the NADH + H+ why is this done?

Answer 12

reduced; oxidized; so that anaerobic glycolysis can continue, bc NAD+ is needed to keep it going

Question 13

Is ATP produced during anaerobic glycolysis/ fermentation? When is this used?

Answer 13

yes, at least a little. lactic acid ferm is used when there is not sufficient oxygen to do aerobic respiration.

Question 14

What is the goal of fermentation?

Answer 14

to regenerate NAD+ so glycolysis can continue under anaerobic conditions and ATP can be generated.

Question 15

What do biochemical tests involve?

Answer 15

detecting a product generated during metabolism

Question 16

in the glucose fermentation test, what is the little tube inside the big tube called? (captures gas)

Answer 16

Durham tube

Question 17

what is an obligate anaerobe? where do they get their energy from? an example?

Answer 17

do not grow if oxygen is present; anaerobic respiration, fermentation, or both; Clostridium perfringens

Question 18

Characteristics of Clostridium perfringens? How does it get its energy? What disease does it cause?

Answer 18

Long rod, forms spores (like bacillus), soil bacteria; fermentation; gas gangrene

Question 19

What does C. perfringens produce to cause the disease? (to degrade tissue and kill cells?)

Answer 19

produces collagenases to degrade connective tissue, and alpha toxin which kills cells; also produces a lot of gas forming pockets

Question 20

When was gas gangrene a large problem? What is done as treatment?

Answer 20

in wartime before antibiotics were discovered; amputations to keep it from spreading

Question 21

Where does the citric acid cycle occur in the bacterial cell?

Answer 21

cytoplasm

Question 22

What does the citric acid cycle generate?

Answer 22

NADH + H+, FADH2, GTP

Question 23

Where does the acetylCoA that is fed into the citric acid cycle come from?

Answer 23

pyruvate from aerobic glycolysis

Question 24

What happens when acetylCoA is fed into citric acid cycle?

Answer 24

the last compound (oxaloacetate) is converted to the first compound (citric acid)

Question 25

In the CAC what happens to NAD+ and FAD?

Answer 25

they are reduced to NADH + H+ and FADH2

Question 26

What happens to the NADH + H+ and FADH2 that are produced from the CAC?

Answer 26

they are moved to oxidative phosphorylation (oxidized so ATP is created)

Question 27

Where does oxidative phosphorylation occur in the cell?

Answer 27

cytoplasm

Question 28

What systems is oxidative phosphorylation made of?

Answer 28

the electron transport system and chemiosmosis

Question 29

where does chemiosmosis occur in the cell?

Answer 29

across inner membrane

Question 30

What happens in oxidative phosphorylation?

Answer 30

NADH + H+ and FADH2 get oxidized and ADP is phosphorylated

Question 31

What happens in chemiosmosis?

Answer 31

protons diffuse thru ATP synthase to provide energy to make ATP

Question 32

what oxidizes the components in oxidative phosphorylation?

Answer 32

chain of inner membrane proteins

Question 33

Where do the H+ come from in the proton gradient?

Answer 33

oxidation of NADH + H+ and FADH2

Question 34

What is the final electron acceptor in aerobic respiration? what is it reduced to?

Answer 34

oxygen; water

Question 35

What enzyme is involved in reducing oxygen to water in aerobic resp?

Answer 35

cytochrome C oxidase

Question 36

What is the oxidase test?

Answer 36

tests whether an organism has cytochrome C oxidase

Question 37

what is cytochrome c oxidase?

Answer 37

multisubunit protein; catalyzes the reduction of O2 to water; found in ETS

Question 38

Where are cytochromes found?

Answer 38

in the electron transport system

Question 39

What do cytochromes contain as a prosthetic group?

Answer 39

heme

Question 40

What is a prosthetic group?

Answer 40

nonprotein compound that binds tightly to a protein and is needed for its function

Question 41

Heme is a _________________. ______________ are a component of heme, there are 4 of them in the organic shell of heme.

Answer 41

tetrapyrrole; pyrroles

Question 42

We also have cytochrome C oxidase, how does it react to carbon monoxide?

Answer 42

carbon monoxide binds to the iron in the heme part, stopping the ETS (can’t generate ATP). Also binds to heme in hemoglobin so it cannot carry oxygen.

Question 43

oxidase test determines if cytochrome C oxidase is present and what else? This applies for most organisms except for which one? How does it test?

Answer 43

does aerobic resp; E. coli is negative on the test but does aerobic resp

Question 44

Is Vibrio cholerae positive or negative on the oxidase test?

Answer 44

positive