Cellular Metabolism

Question 1

Muscle Contraction

Answer 1

Actin + myosin filaments slide across each other -> uses ATP.
The faster the contraction, the faster the use of ATP.
Sacroplasmic reticulum releases calcium -> catalyses sliding of actin + myosin
Calcium gradient in sacroplasmic reticulum needs to be maintained when at rest -> uses a lot of energy (METABOLISM IS NOT JUST OCCURRING WHEN WE ARE PHYSICALLY ACTIVE).

Question 2

Type I muscle cells

Answer 2

Red, lots of mitochondria, good blood supply (surrounded by capillary network), contracts slowly

Question 3

Type II muscle cells

Answer 3

White, few mitochondria, packs cell with muscle fibres (high intensity, powerful contractions however short term), poor blood supply.

Question 4

ATP Production

Answer 4

Low stores of ATP -> as soon as it is used it needs to be replaced