Carbohydrate Metabolism 1 (REVISE)

Question 1

Gluconeogenesis

Answer 1

Metabolic Pathway whereby glucose is generated in the body when it cannot be obtained from diet or liver catabolism of glycogen

Question 2

Vaguely describe precursors of gluconeogenesis

Answer 2

Non-Carbohydrate

Question 3

Where does gluconeogenesis occur

Answer 3

Liver and Kidney

Question 4

Where are the main stores of glycogen in the body

Answer 4

Skeletal Muscle and Liver

Question 5

What are Reducing and Non-Reducing Ends of Glycogen

Answer 5

Question 6

How many Reducing and Non-Reducing Ends are there in a molecule of glucose

Answer 6

Question 7

Glycogen Phosphorylase

Answer 7

Enzyme that breaks up glycogen chains into Glucose-1-Phosphate Molecules

**Part of glycogen breakdown pathway

Question 8

Inhibitors of Glycogen Phosphorylase

Answer 8

ATP, G6P, Glucose

Question 9

Activators of Glycogen Phosphorylase

Answer 9

AMP

Question 10

Glycogen Debranching Enzyme

Answer 10

Bifunctional Enzyme that:

• Acts as an α1-4 transglycosylase and moves trisaccharide units to non-reducing branch end
• Hydrolytically removes remaining molecule using amylo-α(1-6) glycosidase activity
• *dw about enzyme names
• *Part of glycogen breakdown pathway

Question 11

Phosphoglucomutase

Answer 11

Enzyme that phosphorylates G1P into G1,6P; the enzyme gets rephosphorylated to then form G6P

Enzyme is responsible for converting G1P to G6P

**Part of glycogen breakdown pathway

Question 12

Glucose-6-Phosphatase

Answer 12

Enzyme that hydrolises G6P into glucose

Question 13

Glycogen Synthase

Answer 13

Enzyme that makes α1-4 linkages across glucose molecules and extends existing chains

Question 14

UDP-Glucose

Answer 14

Uridine Diphosphate Glucose

Question 15

What molecules are required to synthesise glycogen

Answer 15

α-D-Glucose

ATP
UTP

Question 16

Regulation of Glycogenesis and Glycogenolysis in Liver and SkM

Answer 16

Liver

• Glycogenesis Accelerates during well fed periods
• Glycogenolysis Accelerates during fasting

Muscle

• Glycogenesis Accelerates during rest periods
• Glycogenolysis Accelerates during exercise

Question 17

Key hormones involved in Glycogen Metabolic Regulation

Answer 17

Insulin
Glucagon

Adrenaline

Question 18

How do Adrenaline and Glucagon act on cells

Answer 18

They bind to surface receptors which trigger intracellular events; they use cAMP as a secondary messenger

Question 19

What cells do adrenaline and glucagon act on in glycogen hormonal regulation

Answer 19

Adrenaline - Muscle and Liver

Glucagon - Liver