b3.3- muscle and mobility

Question 1

motile

Answer 1

can move from one place to another

Question 2

sessile

Answer 2

cant move from one place to another

Question 3

how sacromere contracts

Answer 3

1. action potential causes release of calcium ions
2. calcium ions bind to troponin
3. causing tropomyosin to be released from the binding sites
4. exposing binding sites for actin filaments
5. ATP binds to myosin heads and breaking the cross bridges
6. ATP is hydrolysed to ADP and phosphate
7. energy from ATP causes myosin heads to cock (swivel outwards)
8. myosin heads form new cross bridges to new actin binding sites
9. myosin head swivel inwards while releasing ADP and phosphate
10. myosin filaments move actin filaments towards the centre of the sacromere
11. sliding of filament shortens the sacromere
    A Chloe Tryin Expose Acrobatic Ahoy Excepts Makes Minimum Movement Slayed

Question 4

role of protein titin [3]

Answer 4

1. holds the myosin filament in place
2. prevents over stretching of the sacromere
3. helps sacromeres to recoil after stretching

Question 5

antagonistic muscles

Answer 5

• work together: contraction of one provides energy needed for the titin molecules in the other as it relaxes
• cause opposite movements

Question 6

role of antagonistic muscles

Answer 6

• needed because muscle tissue can only exert force when it contracts
• joint angle becomes smaller: flexor muscle
• joint angle becomes larger: extensor muscle

Question 7

motor neuron

Answer 7

carries electrical impulse to muscles

Question 8

muscle fibres

Answer 8

• one motor neuron with all the muscle fibres it stimulates
• acetylcholine as neurotransmitter

Question 9

neuromuscular junctions

Answer 9

synapse between a motor neuron and muscle fibres

Question 10

type of skeleton arthopods have

Answer 10

exoskeleton

Question 11

type of skeleton vertebrates have

Answer 11

endoskeletons

Question 12

fulcrum

Answer 12

middle part below lever

Question 13

effort applied nearer to the fulcrum

Answer 13

force decreases but increases distance moved

Question 14

synovial joints

Answer 14

• capsules that surround the articulating surfaces of two bones (i.e. where the bones connect)
  eg. shoulder

Question 15

role of bones [2]

Answer 15

• provides anchorage for muscle and ligaments
• act as levers

Question 16

cartilage

Answer 16

tough, smooth tissue that covers the bone at the joint

Question 17

role of cartilage [2]

Answer 17

1. prevents friction
2. absorbs shocks

Question 18

synovial fluid

Answer 18

fills a cavity in the joint between the cartilages on the ends of the bones

Question 19

role of synovial fluid [2]

Answer 19

• lubricates the joint- prevent friction
• provides oxygen and nutrition to the cartilage

Question 20

ligaments

Answer 20

tough cords of tissue containing large quantities of protein collagen

Question 21

role of ligaments

Answer 21

prevent aberrant movements- wont dislocate/damage the joint

Question 22

role of muscles

Answer 22

provides forces that cause movement at the joint

Question 23

role of tendons

Answer 23

attaches muscle to bone

Question 24

hinge joint

Answer 24

• one direction
  eg. elbow joint

Question 25

pivot joint

Answer 25

simple rotation: nodding and turning eg. neck

Question 26

internal and external intercostal muscles

Answer 26

muscle fibres orientated differently- alternating contraction of the different layers - moves the ribcage in opposite directions

Question 27

reasons for locomotion [4]

Answer 27

1. foraging for food 2. escaping from danger 3. searching for a mate 4. migration

Question 28

adaptions for swimming in marine mammal [4]

Answer 28

1. streamlining 2. fins, tail and flukes for swimming 3. blowhole- allow periodic diving 4. hairless, smooth skin surface

Question 29

what are troponin and tropomyosin

Answer 29

regulatory porteins

Question 30

structure of muscle fibre

Answer 30

- myofibrils contain repeating units called sacromeres - sacromeres contain actin filaments and myosin filaments - actin fibres are thin and myosin fibres are thick

Question 31

function of joint capsule [2]

Answer 31

- seals the joint space - provides stability by restricting the range of possible movements

Question 32

what happens when the external intercostal muscle contracts

Answer 32

inhalation - ribcage expands - stretches internal intercostal muscles

Question 33

stretching a muscle

Answer 33

stores potential energy in the titin in the msucle

Question 34

function of neurones [2]

Answer 34

- stimulate muscles to contract - control the timing of muscle contraction

Question 35

function of joints

Answer 35

control the range of movement