muscles

Question 1

Compare fast and slow twitch muscle fibres

Answer 1

. Fast twitch have few mitochondria, slow twitch have many
. Fast twitch have no capillaries, slow twitch have many capillaries
. Fast twitch are whitish, slow twitch are reddish as they are rich in myoglobin

Question 2

What do tendons do

Answer 2

Attach skeletal muscles to bones

Question 3

What do ligaments do

Answer 3

attach bone to bone

Question 4

Describe how calcium ions affect troponin as a skeletal muscle fibre contracts.

Answer 4

. Calcium binds to troponin
. Troponin molecules change shape
. This displaces tropomyosin

Question 5

Explain why muscles work in antagonistic pairs

Answer 5

Muscles can only work in one direction

So there must be extensors and flexors

Question 6

Describe muscle contraction

Answer 6

Myosin heads bind to binding sites on actin
Myosin changes shape
Actin filaments slide over myosin
So muscle fibres shorten
ATP is hydrolysed and ADP + phosphate group is released

Question 7

Define cruciate ligament

Answer 7

Connects bone to bone in the knee

Question 8

Define cruciate ligament

Answer 8

Connects bone to bone in the knee

Question 9

Benefits of keyhole surgery

Answer 9

Smaller incision - less chance of infection
Reduces recovery time
Less scar tissue
Less blood loss
Less pain