Muscle Growth, Structure And Proteins

Question 1

Muscle biology

Answer 1

FUNCTIONS
Locomotion → walking, running, and flying
Pumping → heart muscle by circulating blood
Moving foods along the gut (smooth muscle)
ACTIVITIES
Skeletal (movement)
Cardiac (pumping blood)
Smooth muscle (involuntary activities)

Question 2

Muscle types in animal body (skeletal)

Answer 2

Nervous control → voluntary
Banding pattern → striated
Nuclei → multi
Position of nuclei → peripheral

Question 3

Muscle types in animal body (smooth)

Answer 3

Nervous control → involuntary
Banding pattern → non-striated
Nuclei → singe
Position of nuclei → central

Question 4

Muscle types in animal body (cardiac)

Answer 4

Nervous control → involuntary
Banding pattern → striated
Nuclei → singe
Position of nuclei → central

Question 5

Skeletal muscle consist of 3 kinds of tissue:

Answer 5

Muscle tissue (muscle fibers)
Adipose tissue
Connective tissue (3 layers: epimysium, perimysium, and endomysium)

Question 6

Epimysium:

Answer 6

Protects muscles from frictions against other muscles and bennes

Question 7

Levels of functional organization in a skeletal muscle

Answer 7

Muscle
Muscle fascicle (muscle fiber bundles)
Muscle fibers
Myofibrils
Myofilaments

Question 8

Fascia

Answer 8

Layers of dense connective tissue surround and separate each muscle

Fascia extends beyond the ends of the muscle and gives rise to the tendons that are fused to the periosteum

Question 9

Sarcoplasmic reticulum

Answer 9

The endoplasmic reticulum of a muscle cell
Surrounds bundles of contractile proteins (myofibrils)
Contains Ca2+ necessary for muscle contraction

Question 10

Triad

Answer 10

Part of the sarcoplasmic reticulum
A reservoir for Ca2+ ions
2 terminal cisternae and 1 T-tubule = 1 triad

Question 11

Sarcolemma

Answer 11

Covered by basal lamina - this collagen sheet of endomysium
Surrounded by sarcolemma (plasmalema) plasma membrane of the muscle fiber
Invaginations of this membrane termed T-tubules or transverse tubules

Question 12

Myofibrils

Answer 12

Long cylindrical structure of fibers
80% of muscle fiber volume
Each muscle fiber has 100 to 1000
Insoluble at the ionic strengths that exist in the muscle cell

Question 13

Myofilaments

Answer 13

Myosin (thick) and actin (thin) filaments

Question 14

Sacromere

Answer 14

Functional unit of myofibrils
Contractile unit of a muscle

Question 15

The length of the sarcomere are related to ….

Answer 15

Meat tenderness

Question 16

Myofibrillar proteins

Answer 16

Myosin
Actin
Titin (connectin)
Nebulin
Troponin
Tropomyosin
Tropomodulin
Desmin
A-actinin
Cap Z
Myomesin

Question 17

How do muscles grow in length?

Answer 17

Accretion: a growth or enlargement by a gradual build up with adding new sarcomere at the end of muscle fibers

Question 18

Myofibrillar proteins

Answer 18

Although high ionic strength is required to disrupt Myofibrillar, many of them are soluble in water

Soluble in concentrated salt solutions

Question 19

Sarcoplasmic proteins

Answer 19

Soluble in water or dilute salt solutions

Soluble at ionic strength of 0.1M or less at neutral pH

Question 20

Stromal or connective tissue proteins

Answer 20

Insoluble in neutral aqueous solvents and high salt solutions

Soluble in alkaline or acid solutions

Lipoproteins and mucoproteins from cell membranes and surfaces as well as connective tissue proteins

Question 21

Muscle hypertrophy

Answer 21

Myofibrils slit longitudinally to form two new myofibrils, enlarge and become functional by synthesizing contractile, regulatory and structural proteins
One myofibrils can spit into 4+ times
Number of myofibrils increase by 10-15 times during animals lifetime
Myofibrils size increases by increase in Myofilaments (thick and thin)

Question 22

Muscle fiber types: Types I

Answer 22

Slow twitch oxidative type 1

Marathon

Question 23

Muscle fiber types: Types IIA/IIX

Answer 23

Fast/ oxidative-glycolytic

Intermediate

1500m

Question 24

Muscle fiber types: Types IIB

Answer 24

Fast/ glycolytic
White
100m (usain bolt)