Human metabolism lecture 6

Question 1

Types of muscle

Answer 1

• Type 1 (aerobic, ↑ mit density, oxidative, slow)
• SLOW = glucose → glycolysis → Krebs → Etc + can use FFA
• Type IIa (int. of type I/IIb, slow contraction)
• Type IIb (anaerobic, ↓ mit density, fast contraction)
• FAST = glucose → glut4 → glycolysis → lactate

Question 2

Intracellular stores for exercise

Answer 2

• e.g. creatine, glycogen, TAG
• x need to mobilise
• Limited, ↓ E dense

Question 3

Extracellular stores

Answer 3

• e.g. blood glucose, FA
• unlimited in size + ↑ E dense than glucose
• But need to mobilise

Question 4

Muscle regulation during anaerobic exercise

Answer 4

• More E from glycolysis w/ glycogen than glucose
• In exercise, ↓ ATP, ↑ Pi, ↓ creatine phosphate
• Glycogen phosphorylase = activated by Ppi
• PFK regulated in parallel to glycogen breakdown

Question 5

Fatigue in anaerobic exercise

Answer 5

• Lactic acid made to regenerate NAD+
• ↓ pH → less Ca2+ released by sarcoplasmic reticulum
• Inhibits PFK muscle

Question 6

Aerobic exercise

Answer 6

• Type Ib muscle
• Blood glucose = 4 min, liver glycogen = 18 min, muscle glycogen = 70 min
• Adipose TAG → FA, 4018 mins

Question 7

Fatigue in aerobic exercise

Answer 7

• Glycogen stores depleted