energy system in muscle cells

Question 1

what is the only stage of respiration that can occur without the presence of oxygen?

Answer 1

glycolysis

Question 2

what does pyruvate convert into

Answer 2

lactate

Question 3

what causes lactate metabolism?

Answer 3

when muscle cells don’t get enough oxygen to support the electron transport chain, this results in an alternative respiratory pathway.

Question 4

what is added to pyruvate during lactate metabolism?

Answer 4

hydrogen, NAD must ‘transfer’ its hydrogen to become free to allow glycolysis to continue.

Question 5

lactate builds in the muscle tissues, why is this a problem?

Answer 5

the build up of lactate lowers the pH of muscle cells, causing acidosis in muscle tissue.

Question 6

what is the pain in muscles called

Answer 6

muscle fatigue

Question 7

why is the process of lactate metabolism reversible?

Answer 7

a period of rest allows the ocygen debt to be repaid.

Question 8

what is myoglobin and what does it do?

Answer 8

myoglobin has a very high affinity for oxygen and binds with it. It extracts 02 from blood in high concentrations and stores it for muscle cells to use in aerobic respiration.

Question 9

what are the 2 types of skeletal muscle fibres called

Answer 9

• fast twitch
• slow twitch

Question 10

name some slow twitch muscle fibre properties.

Answer 10

contraction time : slow
respiration : aerobic
number of mitochondria: high
blood supply: good/better
myoglobin: high concentration
fuel used: fats

Question 11

name some fast twitch muscle fibre properties.

Answer 11

contraction time : fast
respiration : anaerobic
number of mitochondria: fewer/less
blood supply: lower
myoglobin: lower concentration
fuel used: glycogen

Question 12

what activities would best suit the muscle fibres?

Answer 12

fast twitch = sprint
slow twitch = marathon (endurance)