Lab 5 - Microscopic Features of Skeletal Muscle

Question 1

Sarcoplasmic Reticulum

Answer 1

smooth endoplasmic reticulum of muscle
-stores Ca^2+ when muscle is relaxed
-releases Ca^2+ when muscle is released

Question 2

T tubule

Answer 2

deep invaginations on the sarcolemma
-allows impulses to quickly travel and stimulate both superficial and deep muscle fibers

Question 3

Myosin

Answer 3

proteins that bind to actin; composed of a tail and one or two myosin heads; pulls actin

Question 4

Actin

Answer 4

protein that myosin heads attached to during contraction

Question 5

Thick Filament

Answer 5

central filament of sarcomere composed of myosin

Question 6

Thin Filament

Answer 6

outer/smaller filaments of the sarcomere composed of actin

Question 7

Titin

Answer 7

large protein between thick filament (myosin) and ends of the sarcomere
-stabilizes the position of thick filament

Question 8

Tropomyosin

Answer 8

strand of protein which covers myosin binding sites on actin

Question 9

Tropoin

Answer 9

regulatory protein that will move tropomyosin with Ca^2+ binds

Question 10

A Band

Answer 10

contains the entire length of myosin

Question 11

I Band

Answer 11

thin filament that is not super imposed by thick filament (only thin filament)

Question 12

Z Line

Answer 12

the boundary ends of the sarcomere that thin filaments and titin extend form

Question 13

M Line

Answer 13

region in the middle of the sarcomere with proteins that hold together thick filament

Question 14

Sacromere

Answer 14

basic unit of skeletal muscle (like osteon basic “unit” of bone)

Question 15

H Zone

Answer 15

thick filament not super imposed by thin filament (only thick filament)