Skeletal Muscle: Molecular Basis Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What are Transvers Tubules?

A
  • Invaginations of sarcolemma into the center of the cell
  • Contain voltage gated L type DHPR Ca channels
  • Many other types of Na,K, and Ca channels and pumps.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the SR?

A
  • system of tubular sacs
  • stores high concentrations of Ca
  • Contains DHPR activated channels (Ryanodine receptors)
  • Release Ca to trigger muscle contraction and SERCA to pump Calcium back in
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a sarcomere?

A

The Contractile Unit of muscle made of myofilament proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the role of nebulin Nd other Z disc proteins??

A

Anchor thin filaments in place

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the role of Titian?

A

Large protein which spans entire sarcomere which helps to prevent pulling apart and in elastic recoil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the troponin complex, and what are its components?

A

Protein which regulates beginning and end of contraction based on calcium iron concentrations

Troponin C - Calcium binding unit
Troponin I - Inhibitory subunit which regulates actin-tropomysoin interaction
Troponin T: Tropomyosin binding subunit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What events follow Ca binding to troponin?

A
  1. Troponin-tropomyosin move and allow myosin to interact with actin
  2. Myosin produces contraction (shortening)
  3. Ca is pumped back into SR/out of cell
  4. Relaxation occurs when Ca unbind from troponin which results in troponin-tropomyosin preventing myosin from binding actin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the role ofATP in Muscle contraction?

A

During Contraction, ATP binds to myosin causing dissociation of myosin from actin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the sliding filament model of muscle contraction.

A
  • “swinging lover arm”
  • Shortening occurs due to movement of actin filament over myosin
  • Formation of crossbridges btwn actin and myosin makes power stroke
How well did you know this?
1
Not at all
2
3
4
5
Perfectly