Muscle

Question 1

Muscle

Answer 1

Highly specialized tissue with ability to contract in response to stimuli

Question 2

What three types of muscles do vertebrates have?

Answer 2

skeletal, cardiac, smooth

Question 3

what is the organization of the muscle?

Answer 3

muscle–> muscle fiber–> myofibril

Question 4

sarcomere

Answer 4

The basic unit of contraction. gives muscle a striated appearance.

Question 5

Myosin contains what two kinds of filaments?

Answer 5

1.Thick filaments;
– Composed primarily of myosin;
2. Thin filaments;
– Composed of two chains of globular actin, wrapped around each other in a helix;

Question 6

Titin

Answer 6

Structural elastic protein that align actin and myosin;an accessory protein for contraction.

Question 7

What do tropomyosin and troponin do>

Answer 7

Associated with the actin chains of the thin filaments;

– Regulate contraction by controlling the interaction of the cross bridges with the thin filaments.

Question 8

What happens during a muscle contraction?

Answer 8

the muscle fibbers contract, the thin and thick filament slide over each other.

Question 9

what are the signals for a muscle contraction?

Answer 9

Motor neurons from the somatic NS generate action potentials that liberates ACh

ACh is secreted into the neuromuscular junction and binds to nicotinic receptors in the muscle cell membrane

Ca2+ is liberated from the sarcoplasmic reticulum


Question 10

what does myosin ATPase catalyze?

Answer 10

the decomposition of ATP into ADP

Question 11

In the absence of calcium what does tropomyosin do?

Answer 11

tropomyosin cover myosin-binding sites;

Question 12

The binding of Myosin to actin create the formation of what?

Answer 12

crossbridge

Question 13

where is calcium taken once the action potentials stop after muscle contraction?

Answer 13

sarcoplasmic reticulum.

Question 14

What are the 3 types of muscle fibbers?

Answer 14

– Slow oxidative fibres; – Fast oxidative fibres; – Fast glycolitic fibres.

Question 15

oxidative fibers

Answer 15

Contain large number of mitochondria:
– High capacity for oxidative phosphorylation:
– Surrounded by many small blood vessels;

Question 16

What colour of meat is oxidative fibbers?

Answer 16

Red meat. i.e breast of a duck

Question 17

glycolytic fibers

Answer 17

Few mitochondria but high concentration of glycolytic enzymes and large stores of glycogen;
– Limited use of oxygen;
– Few blood vessels
– Little myoglobin,

Question 18

What are the 3 major types of muscle fibers>

Answer 18

1. slow oxidative fibers
2. fast oxidative fibers
3. fast glycolytic fibers

Question 19

slow oxidative fibers

Answer 19

Have low rates of myosin ATPase activity but have the ability to make large amounts of ATP
– Do not fatigue easily;
– Used for prolonged, regular activity;
• flight, long-distance swimming;

Question 20

Fast oxidative fibers

Answer 20

Fast-oxidative fibres:
– Have high myosin ATPase activity and can make large amounts of ATP;
– Do not fatigue quickly and can be used for long-term activities;
– They are particularly suited for rapid actions;

Question 21

fast glycolytic fibers

Answer 21

High myosin ATPase activity but cannot make as much ATP as oxidative fibres, because their source of ATP is glycolysis;
• Best suited for rapid, intense actions;
– Short sprint at maximum speed or a cat
pouncing on its prey;
• Fatigue more rapidly than oxidative fibres;

Question 22

Aerobic exercise of low intensity but long duration, increase what?

Answer 22

the number of mitochondria in the slow-oxidative fibres;

Question 23

High-intensity exercise of short-duration affects what?

Answer 23

fast-glycolytic fibres, which are used during strong contractions:

Question 24

What type of muscles are striated muscles?

Answer 24

Skeletal muscle and cardiac muscle

Question 25

What type of muscles are unstriated muscles?

Answer 25

Smooth muscle

Question 26

Striated muscle are

Answer 26

muscle tissue that has repeating sarcromeres in contract with smooth muscle tissue.

Question 27

The basic unit of contraction is termed the

Answer 27

Sarcomere

Question 28

Tendons:

Answer 28

Connective tissue that link bone to skeletal muscles

Question 29

What are the 2 roles of ATP:

Answer 29

1. Binding ATP to myosin decreases affinity for actin.

2. Following dissociation ATP is hydrolyzed energizing myosin.