Skeletal muscle

Question 1

What are the 3 main types of muscle?

Answer 1

Involuntary
Cardiac
Skeletal

Question 2

What is the function and structure of skeletal muscle

Answer 2

Its function is to move limbs
Its structure is Striated, Tube shaped and Multinucleated

Question 3

What is the function and structure of cardiac muscle

Answer 3

Function: Pump blood
Structure: Striated, Branched and Unnucleated

Question 4

What is the function and structure of involuntary muscle

Answer 4

Function: Allowing the movement of substances E.g Veins
Structure: Non-striated, Spindle shaped and Unnucleated

Question 5

What are skeletal muscles made of?

Answer 5

Bundles of muscle fibres and a single muscle fibre is made from many MYOFIBRILS

Question 6

What are myofibrils made of?

Answer 6

Thin and Thick filaments

Question 7

What are THIN filaments made of?

Answer 7

2 Actin chains with and a tropomyosin chain wrapped around each other

Question 8

What are THICK filaments made of?

Answer 8

Bundles of to myosin chains wrapped together forming a head and tail

Question 9

Name all the components of a Sarcomere (draw it to help)
(7)

Answer 9

Thick filament
Thin filament
M - Line (thick)
Z - Line (thin)
Light/I band(thin)
Dark/A band(thin x thick)
H - ZONE (just thick not thin and thick overlap)

Question 10

What is the sliding filament mechanism? (6)
Croc,Bad D,bond head,Buss stroke…

Answer 10

1)The sarcoplasmic reticulum releases Ca2+
2)Ca2+ causes Tropomyosin to move and expose the active sites it was blocking
3)A myosin head binds to the active site forming a ACTINOMYOSIN BRIDGE
4) ADP and Pi are released from the myosin head stiming a power stroke towards the M-line
5)ATP binds to the myosin head and detaches from the Actin
6)By hydrolysing the ATP it returns to its starting position

Question 11

What happens to the:
I/light band
A/Dark band
H-ZONE
when the sarcomere contacts

Answer 11

I band is Narrower
A band is the Same
H-zone is Narrower