skeletal muscles

Question 1

define:💓
I-Band
A-Band
H-Zone
Z-Line

Answer 1

I-only actin present
A-where myosin is present (actin can be 2)
H-area of A where there’s only myosin
Z-at the centre of I (distance betw Z-lines makes a sarcomere

Question 2

describe muscle contraction💓🙏💓🙏💓

Answer 2

as AP reached sarcoplasmic retic, ca2+ channels open and it diffuses into sarcoplasm. troponin is blocking the binding site so ca2+ bind to it- causes tropomyosin to move. myosin and actin form a myosin-actin cross bridge. ca2+ activated ATPase which breaks ATP to ADP+Pi- releases energy which moves myosin head. free ATP binds to myosin head- changing its shape. A-M cross bridge breaks. head returns to original shape and position.

Question 3

sliding filament model?🏄🏼‍♀️🌃🌞🍸

Answer 3

the sarcomere is pulled in opposite directions- towards each other.
as filaments slide over each other- sarcomere shortens

Question 4

slow twitch muscle fibres🌞

Answer 4

aerobic respiration
release ATP slowly
continuous and extended muscle contractions over a long period of time
more mitochondria
dense capillary network
red meats

Question 5

fast twitch muscle fibres🍸

Answer 5

anaerobic resp - large glycogen store provides fuel for this
contracts rapidly but fatigues quickly
few mitochondria
few capillaries
white meats