Muscles

Question 1

What attaches skeletal muscles to the bone

Answer 1

Tendons

Question 2

What do ligaments attach

Answer 2

Bone to bone

Question 3

Why can bones act as levers

Answer 3

They are rigid

Question 4

What are antagonistic pairs

Answer 4

Muscles that work together to move a bone
Agonist = contracts
Antagonist = relax

Question 5

What are muscles made of

Answer 5

Muscle fibres

Question 6

What is the cell membrane of muscle fibres called

Answer 6

Sarcolemma

Question 7

What is the cytoplasm of muscle fibres called

Answer 7

Sarcoplasm

Question 8

What are the folds in the sarcolemma called

Answer 8

Transvers (T) tubules

Question 9

What is the function of the t tubules

Answer 9

Spread electrical impulses throughout sarcoplasm to reach all parts of the muscle fibre

Question 10

What is the function of the sarcoplasm in reticulum

Answer 10

Stores and releases Ça ions

Question 11

What is an adaption of muscle fibres

Answer 11

Lots of mitochondria for ATP

Question 12

What does multinucleate mean

Answer 12

Lots of nuclei

Question 13

What is the name of the thick myofilament

Answer 13

Myosin

Question 14

What is the name of the thin myofilament

Answer 14

Actin

Question 15

What is the dark band on a myofibril

Answer 15

Myosin and actin

A band

Question 16

What is the light band on a myofibril

Answer 16

Actin only

I band

Question 17

What is at the end of each sarcomere

Answer 17

Z line

Question 18

What is the middle of a sarcomere

Answer 18

M line

Question 19

What area only contains myosin

Answer 19

H zone

Question 20

Explain the sliding filament theory

Answer 20

Myosin and actin filaments slide over each other making the sarcomere contract. Not contracting themselves.
The simultaneous contraction of lots of sarcomeres mean the muscle fibres contact

Question 21

What happens to the individual sarcomeres as the muscle fibres contacts

Answer 21

A band stays the same length
I band shorter
H zone shorter
Sarcomere overall gets shorter

Question 22

What is the structure of myosin

Answer 22

Has a globular head that’s hinged to move
It has 1 binding site for actin
And 1 binding site for ATP

Question 23

What is the structure of actin

Answer 23

Has a binding site to myosin = actin myosin binding site

Question 24

What the status of the actin myosin binding site at rest

Answer 24

It’s blocked by tropomypsin

Question 25

Why does the actin myosin binding site being blocked mean the myofilaments can’t slide

Answer 25

The myosin heads can’t bind to the actin myosin binding site

Question 26

Explain how muscle contract

Answer 26

1. Ap from motor neurone stimulates muscle cells 2. Sarcolemma depolarised 3. Depolarisation spreads by t tubules to sarcoplasmic reticulum 4. Ça released into sarcoplasm by sarcoplasmic reticulum 5. Ça binds to protein attached to tropomyosin 6. Protein changes shape. 7. Tropomyosin pulled out of actin myosin binding site on actin 8. Binding site is exposed 9. Myosin head binds to actin forming an actin myosin cross bridge 10. Ça activate ATP hydrolase = breaks down ATP 11. Energy from ATP used to bend myosin head 12. Pulling actin 13. Energy from ATP breaks actin myosin cross bridge 14. Myosin head reattaches to another binding site further along actin filament 15. Sarcomere shortens

Question 27

What happens to the muscle when it stops being stimulated

Answer 27

Ça ions leave binding site Move back into sarcoplasm Reticulum by at Tropomyosin moves back to block actin myosin binding sites Actin filaments slide back to the relaxed positions Sarcomere lengthens

Question 28

How would u tell from the sarcomere it is not contracted

Answer 28

No actin myosin cross bridges

Question 29

How is atp generated by aerobic respiration

Answer 29

Oxidative phosphorylation in mitochondria

Question 30

Where does oxidative phosphorylation happen

Answer 30

Mitochondria

Question 31

When is aerobic respiration a good atp source

Answer 31

Long duration | Low intensity

Question 32

How is atp made during anaerobic respiration

Answer 32

Glycolysis makes pyruvate | Pyruvate -> lactate (by lactate fermentation)

Question 33

Why can anaerobic respiration only be used in short periods

Answer 33

Lactate builds causing muscle fatigue

Question 34

How is atp made by the atp-phosphocreatine system

Answer 34

Phosphorylate ADP by adding a pi group from PCr (créatine)

Question 35

Where is PCr stored

Answer 35

Inside cells

Question 36

How fast does the ATP-PCr system make atp

Answer 36

Very quickly

Question 37

What type of excercise is the PCr-AtP system used for

Answer 37

Short duration | High intensity

Question 38

Is atp-pcr system anaerobic or aerobic

Answer 38

Anaerobic

Question 39

Is the atp-pcr system lactic or alactic

Answer 39

Alactic

Question 40

What is créatine broken down into

Answer 40

Creatinine

Question 41

Where is créatine broken down

Answer 41

Kidney

Question 42

Who might have high creatinine levels

Answer 42

People who exercise a lot People with high muscle mass People with kidney damage

Question 43

When are slow twitch muscle fibres used

Answer 43

Used for posture Used in endurance Long duration

Question 44

What type of respiration do slow twitch muscle fibres use

Answer 44

Aerobic

Question 45

What type of respiration do fast twitch muscle fibres use

Answer 45

Anaerobic

Question 46

What are 2 specialisation of slow twitch muscle fibres

Answer 46

Lots of mitochondria = supply muscles with energy from atp | Lots of blood vessels = supply muscles with oxygen

Question 47

When are fast twitch muscle fibres used

Answer 47

Fast movements Short duration High intensity

Question 48

Why are slow twitch fibres red

Answer 48

Have lots of myoglobin (stores oxygen)

Question 49

Why are fast twitch white

Answer 49

Don’t have much myoglobin | Don’t store much oxygen