F cell energy 1:metabolism, ATP, glycolysis

Question 1

What are catabolic processses?

Answer 1

the breakdown of
complex molecules to release energy

Question 2

What is anabolic processes?

Answer 2

synthesis of new
molecules from less complex components

Question 3

What does the oxidation of carbohydrates, fats and proteins produce?

Answer 3

When oxidised they produce water, carbon dioxide and ATP

Question 4

What are the cofactors central to metabolism used for oxidation/reduction reactions?

Answer 4

NAD and FAD are activated carriers of electrons used for oxidation/reduction reactions

Question 5

What is the oxidised and reduced form of NAD?

Answer 5

NAD+ –oxidised form

NADH + H+. –reduced form

Question 6

What is the oxidised and reduced form of FAD?

Answer 6

FAD+ –oxidised form

FADH2 –reduced form

Question 7

What are major oxidative pathways?

Answer 7

• Glycolysis
• Citric acid cycle
• Electron transport coupled to oxidative
  phosphorylation
• Fatty acid oxidation

Question 8

What are the steps involved in glycolysis?

Answer 8

1. Glucose(C6) will become G-6-P with the use of ATP
2. G-6-P will then become fructose 6 phosphate, which well then convert into fructose 1,6 bisphosphate(C6) using ATP.
3. This fructose 1,6 bisphosphate splits into 2 C3 molecules.
4. One of the C3 molecules will be converted into phosphoenol pyruvate by phosphorylating NAD+,pi and ADP. This phosphoenol pyruvate then become pyruvate(C3) by phosphorylating ADP. This steps occurs twice for each C3 molecule.

Question 9

What is the balance sheet for glycolysis?

Answer 9

Reactants:
1 Glucose
2 NAD+
2 ADP
2 Pi

Products:
2 Pyruvate
2 NADH
2 ATP

Question 10

What are potential sites for regulation in glycolysis?

Answer 10

Enzymes catalysing irreversible reactions are potential sites
for regulation

Question 11

What can activity of the enzymes involved in glycolysis be regulated by?

Answer 11

• reversible binding of allosteric effectors
• covalent modification
• transcription

Question 12

What is glycolysis in muscle regulated to meet the need for?

Answer 12

In muscle glycolysis is regulated to meet
the need for ATP

Question 13

What is the the signal for low energy state in muscles?

Answer 13

AMP

Question 14

What is the most important control point in glycolysis in muscles?

Answer 14

Phospho-fructokinase

Question 15

What enzyme does a high concentration of ATP inhibit and how is this done so in muscles?

Answer 15

High concentrations of ATP inhibit PFK
by lowering the affinity for
Fructose 6 phosphate

Question 16

What other factor inhibits PFK in muscles?

Answer 16

pH

Question 17

What does the inhibition of PFK lead to the inhibition of in muscles?

Answer 17

Inhibition of PFK leads to inhibition of hexokinase

Question 18

What does a high concentration of ATP inhibit in the liver?

Answer 18

High concentrations of ATP inhibit PFK

Question 19

What inhibits PFK in the liver?

Answer 19

PFK is inhibited by citrate

Question 20

What is PFK stimulated indirectly by in the liver?

Answer 20

PFK is stimulated indirectly by a build up of F6P

Question 21

What is hexokinase inhibited by in the liver?

Answer 21

Hexokinase is inhibited by G6P

Question 22

What does galactose do in glycolysis?

Answer 22

Converted into Glucose(C6) to be used in glycolysis to form G-6-P

Question 23

What does fructose from adipose do in glycolysis?

Answer 23

Converted into fructose-6-phosphate

Question 24

What does fructose from liver do in glycolysis?

Answer 24

Converted into DHAP and GAP

Question 25

What does pyruvate convert into in glycolysis in exercising muscles?

Answer 25

-Lactate, NADH–>NAD+ and Acetyl CoA

Question 26

What is the acetyl CoA in muscles produced, used for?

Answer 26

Oxidative phosphorylation

Question 27

Why do tumours use the glycolysis pathway?

Answer 27

Their energy needs are met through anaerobic respiration.

Question 28

What does low oxygen stimulate?

Answer 28

Low oxygen stimulates the expression of
many glycolytic enzymes