Biochemistry final content chapters 12,13,10, 16, and all previous info

Question 1

Glycolysis Overview- Reaction 1

Answer 1

Hexokinase- and is the first ATP investment

Question 2

What prevents Glucose escaping from cells

Answer 2

A nucleophilic substitution

Question 3

What has a low km for isoforms I, II, and III?

Answer 3

Broad Substrate specifically (fructose, mannose)

Question 4

High Km for Hexokinase IV

Answer 4

liver enzymes also called Glucokinase

Question 5

What contributes towards the role of the liver as “glucostat”?

Answer 5

Hexokinase IV, allowing the liver to adjust its rate of glucose utilization in response to varying blood glucose levels.

Question 6

Which reaction within Glucose sets the state for a symmetric aldol cleavage?

Answer 6

Reaction 4

Question 7

What is the second ATP investment?

Answer 7

Phosphofructokinase

Question 8

What is a major control point for glycolysis?

Answer 8

PFK: which is an allosteric enzyme

Question 9

Reaction 4-Fructose-1,6-biphosphate aldolase

Answer 9

cleavage to two triose phosphates

Question 10

Under intracellular conditions, what is delta G?

Answer 10

Delta G is negative so that the reverse reaction proceeds as written into vivo. It is a reverse reaction of carbonyl condensation.

Question 11

Reaction 6 has two roles

Answer 11

1. Oxidation of the GAP creates 1 molecule of NADH

2. Creates a high energy 1,3 BPG

Question 12

What does GADPH do?

Answer 12

conserves the energy of oxidation by coupling an exergonic reaction to an endergonic reaction. An energonic reaction is coupled to an exergonic reaction. It is coupled via formation of a thioester intermediate by enzyme.

Question 13

Which two reactions is the energy of oxidation of an aldehyde to a carboxylic acid conserved in the form of ATP?

Answer 13

1,3-Bisphosphoglycerate(BPG), 3-Phosphoglycerate(3PG)

Question 14

Reaction 8:Phosphoglycerate mutase

Answer 14

preparing to synthesize the next “high-energy” compoind

Question 15

Reaction 9: Enolase-synthesis of the second “high energy” compound

Answer 15

This is an a,b elimination

Question 16

Reaction 10: Pyruvate kinsase

Answer 16

the second substrate-level phosphorylation

Question 17

Pk mechanism

Answer 17

Although the synthesis of ATP is an endergonic step, the overall reaction is exergonic because of the spontaneous tautomerization of the enolpyruvate to the more stable keto form (pyruvate)

Question 18

Within Aerobic and anaerobic fates of glycolysis, what may NADH be oxidized to?

Answer 18

NAD+ in the citric acid cycle (aerobic fate)

Question 19

NADH may also be

Answer 19

converted to NAD+ by transfer of electrons to an electron acceptor (anaerobic fate)

Question 20

What are two common anaerobic fates?

Answer 20

Homolactic fermentation and alcoholic fermentation

Question 21

Within anaerobic fates of pyruvate

Answer 21

NADH must be reoxidized to NAD+ for glycolysis to continue

Question 22

What cannot keep up with the NADH produced by high rates of glycolysis

Answer 22

Oxidation in mitochondria

Question 23

What lacks mitochondria?

Answer 23

Anaerobic organisms

Question 24

Within lysozymes of lactate dehydrogenase

Answer 24

non-denaturing gel,;i.e. no SDS added

Question 25

lysozymes catalyze the same chemical reaction but

Answer 25

have different sequences

Question 26

What is a tetrametric protein?

Answer 26

LDH and it consists of M and subunits with small sequence differences

Question 27

What are used diagnostically to monitor heart or muscle disease?

Answer 27

Lysozyme patterns, because disease affected cells will release cell content.