Cross-bridge cycling Flashcards Preview

BIOLOGY 1103 > Cross-bridge cycling > Flashcards

Flashcards in Cross-bridge cycling Deck (11):
1

What do calcium ions bind to that exposes binding sites for the myosin cross-bridges?

Troponin

2

Step 1 of contraction cycle

ATP Hydrolysis
- ATP provides energy to move myosin molecules back into the energized configuration to preform a power stroke (contraction)

3

Step 2 of contraction cycle

Cross-bridge attachment
- Myosin temporarily binds to actin

4

Step 3 of contraction cycle

Power Stroke
When the phosphate is released, the myosin filament moves actin towards the center of the sarcomere. ADP is released.

5

Step 4 of contraction cycle

Cross-bridge detachment
- Binding of ATP to myosin cross-bridge detaches myosin from actin

6

Creatine Phosphate

Transfer high energy phosphate group directly to ADP, producing ATP

7

Anaerboic Cellular respiration

Produces lactic acid by breaking down glucose with ATP

8

Aerobic respiration

yields 36 ATP molecules. Enables prolonged muscle activity

9

Sources of oxygen for muscle contraction

Diffusion from blood
From the oxygen-binding molecule: myoglobin

10

Calcium ions move from the cytoplasm (sarcoplasm) into the sarcoplasmic reticulum because of the action of

active transport pumps in the sarcoplasmic reticulum membrane

11

True or False
Increasing the sarcomere length so that the actin and myosin do not touch results in an increase of tension during muscle contraction.

False