atp and muscle fibres etc

Question 1

what does acetylcholine attach to when diffused across a synapse

Answer 1

• the protein receptor sites on the sarcolemma

Question 2

what stimulates calcium ions

Answer 2

– Acetylcholine attaches to the protein receptor sites causing sodium ions to be released
- The entering of sodium ions produces an action potential
- Action potential along the sarcolemma
-

Question 3

how does calcium allow actin myosin cross bridges to be formed

Answer 3

• the initial binding site is blocked by tropomyosin
  -the release of sodium ions cause release of calcium ions from the sacroplastic reticulum
  -they attach to the tropomyosin , causing it to change shape so myosin can attach to actin

Question 4

which muscle fibres contract fast

Answer 4

fast muscle fibres

Question 5

which muscle fibres contract slow

Answer 5

slow muscle fibres

Question 6

which muscle fibres have many mitochondria

Answer 6

slow muscle fibres

Question 7

whihc type of respiration do slow muscle fibres use

Answer 7

aerobic -energy is released slowly for endurance

Question 8

which respiration do fast muscle fibres use

Answer 8

anaerobic - energy released quickly

Question 9

which type of muscle fibre has high amount of glycogen

Answer 9

fast muscle fibres
to provide lots of glucose as less energy released per glucose molecule

Question 10

which type of muscle fibres have allot of phosphocreatine

Answer 10

fast muscle fibres

Question 11

what 3 reasons is ATP important during muscle contraction

Answer 11

• to move myosin heads which pulls actin filaments
  -to detach myosin heads , breaking actin myosin bridges
  -for the reabsorption of calcium ions into the endoplasmic reticulum by active transport

Question 12

where is phosphocreatine stored

Answer 12

in muscle

Question 13

what is phosphocreatine used for

Answer 13

-reserve supply of phosphate to combine with ADP to form ATP

Question 14

why is phosphocreatine important in fast muscle fibres

Answer 14

can combine with ADP to form ATP quickly in ANAEROBIC conditions very quickly

Question 15

what are the negatives of phosphocreatine

Answer 15

used up very quickly

Question 16

how is phosphocreatine reformed

Answer 16

-using phosphate from ATP when the muscle is relaxed

Question 17

what is ATP produced bt in anaerobic respiration

Answer 17

glycolysis ,which produces pyruvate

Question 18

why is anaerobic respiration used for short periods of hard exercise

Answer 18

because when o2 is short in supply, pyruvate is converted into lactate which binds up in muscles causing muscle fatigue .