Module 4: Metabolism and Bioenergetics

Question 1

anabolism vs catabolism

Answer 1

ana (biosynthesis): requires energy input, endergonic, G>0

cat (degradation): liberates energy, exergonic, G<0

Question 2

phosphoanhydride bonds

Answer 2

joins 3 phosphate groups on nucleotide in ATP

cleaving: releases energy due to instability caused by neg phosphate

Question 3

glycolysis

Answer 3

oxidation of glucose to 2ATP+2 pyruvate

Question 4

TCA (tricarboxylic acid) cycle

Answer 4

further oxidation of pyruvate into CO2 in mitochondria

Question 5

Redox reaction

Answer 5

oxidizing agent: receives e-

reducing agent: donates e-

Question 6

combustion vs degradation of glucose

Answer 6

comb: large Ea, no energy storage
deg: series of rxn w small Ea, energy released stored as Ea

Question 7

aerobic vs anaerobic metabolism

Answer 7

aerobic: glucose fully oxidized to CO2– obtains more ATP/gluc
ana: glucose partially oxidized to lactate or ethanol, smaller G

Question 8

glycolysis w anaerobic

Answer 8

NADH reoxidizes into NAD via production of ethanol or lactate

Question 9

glycolysis w aerobic

Answer 9

pyruvate completely oxidized into CO2, creates more NADH which produces more ATP

Question 10

glycolysis steps (2)

Answer 10

1. preparatory: creates 2 G3P which originate from 2 ATP (invest 2 ATP)
2. payoff: energy production when 2G3P converted to 2 pyruvate– produces 4 ATP
   overall: 2 ATP

Question 11

fermentation: anaerobic metabolism

Answer 11

• glycolysis produces NADH from NAD
• reduction of NAD oxidizes glucose to 2 pyruvate
• NADH regenerated to ethanol (ethanol ferm) or lactate (lactic acid Ferm)

Question 12

citric acid cycle (aerobic metabolism)

Answer 12

1. glycolysis: NAD reduction to NADH

2. fermentation: given by oxidation of NADH, NADH reduces pyruvate to ethanol/lactate

Question 13

mitochondrial matrix

Answer 13

• where citric acid enzyme are

- pyruvate diffuses thru outer membrane w help of pyruvate translocase

Question 14

oxidative phosphorylation step

Answer 14

1. oxidation reaction to from H gradient: e- delivered by NADH
2. phosphorylation (gradient driven synthesis of ATP): e- flow from outer to inner membrane, uses proton motive force from 1

Question 15

electron transport train

Answer 15

• 24 e created from glucose oxidation
• 12 pairs stored in 12 NADH
• pairs passed to protein to form ETC

Question 16

anaerobic respiration

Answer 16

final electron acceptor is not oxygen

Question 17

cell growth stoic: RQ=?

Answer 17

co2 produced/o2 consumed

Question 18

growth medium types (4)

Answer 18

defines: known ingredients and amounts
undefined: unknown
basal: buffer, salt, vitamin, no protein
complete: basal+protein