12.1 continued

Question 1

Z disk, sacromere, H zone, I band, A band, M line are a part of the (fig. 12.3)

Answer 1

myofibril

Question 2

Structures of the thick filament?

Answer 2

Mysoin tail, hinge region ,and myosin heads

Question 3

Thin filament structure

Answer 3

Actin- has the regulatory protiens troponin and tropomyosin, also has the accessory proteins nebulin and titin

Question 4

Extensions of the cell membrane (sarcolemma) that associates with the ends (terminal cisternae) of the sarcoplasmic reticulum

Answer 4

T tubules

Question 5

Stores Ca2+

Answer 5

sarcoplasmic reticulum

Question 6

Muscle cell=

Answer 6

muscle fiber

Question 7

cell membrane=

Answer 7

sarcolemma

Question 8

Cytoplasm-

Answer 8

sarcoplasm

Question 9

Modified ER =

Answer 9

Sarcoplasmic reticulum

Question 10

The contractile unit of the myofibril

Answer 10

sarcomere

Question 11

Overall contractile structure is called

Answer 11

Myofibril

Question 12

Explain the ZIAHM of the myofibril

Answer 12

1. Z disks have filaments between them
2. I band is made of thin filaments only (actin)
3. A band is made of darker regions where both light and heavy filaments overlap
4. The H zone is a clear band in the middle of the A band, with heavy filaments only
5. The M line represents the proteins to which heavy filaments attach

Question 13

Made up of thin filaments only (actin)

Answer 13

I band

Question 14

made up of darker regions where both light and heavy filaments overlap

Answer 14

A band

Question 15

a clear band in the middle of the A band, heavy filaments only

Answer 15

H zone

Question 16

represents the proteins to which heavy filaments attach

Answer 16

M line

Question 17

have filaments between them

Answer 17

Z disks

Question 18

Has accessory proteins that link the thin filaments together, similar to the accessory protein shown for the M line. Myosin heads are omitted for simplicity.

Answer 18

Z disk