Section 8, Exam 4

Question 1

The binding of Ca++ with troponin increases the activity of ________, which leads to an increase of ____ and ____

Answer 1

ATPase; ADP; pi

Question 2

What happens when Ca++ is released to the muscle cell cytoplasm?

Answer 2

It binds with troponin, and tropomyosin rolls off the binding site for actin so myosin can bind to it

Question 3

What are the three phases of the sliding filament theory of muscle contraction?

Answer 3

I. Myosin coupling phase
II. Energy transfer phase (with recharging subphase)
III. Relaxation phase

Question 4

What happens in the first phase of the sliding filament theory?

Answer 4

Ca++ presence increases in the cytoplasm

Question 5

What happens in the second phase of the sliding filament theory?

Answer 5

ATP is converted to ADP and pi; ATP = 10nm pull of actin by myosin, pi breaks actomyosin bond

Question 6

The second phase of the sliding filament continues until..

Answer 6

1. Motor unit activation ceases - ca++ reenters SR

2. Fatigue occurs: H+ increases and prevents Ca++ from binding with troponin

Question 7

What happens in the third phase of the sliding filament theory?

Answer 7

Tropomyosin shifts, blocking myosin binding site preventing actin and myosin from binding

Question 8

What molecules are used for energy in anaerobic exercise that are short duration

Answer 8

Creatine and glycogen

Question 9

What is the energy source that is immediate and is used as the first line during the first seconds of exercise?

Answer 9

Creatine

Question 10

What is an immediate energy source that can be broken down anaerobically and aerobically; it is the second energy source that is used during the first seconds to minutes of exercise?

Answer 10

Glycogen

Question 11

What is used during long duration exercise, during continuous exercise from minutes to hours; gets broken down by oxidative phosphorylation?

Answer 11

Glycogen and fatty acids

Question 12

What are the direct energy sources (stored in muscle)?

Answer 12

1. ATP (5mm)
2. Creatine phosphate (17mm)
3. Glycogen (13-15mm)
4. Fat - triglycerides

Question 13

What are the indirect energy sources?

Answer 13

1. Glycogen (–>Glucose from liver)
2. Triglycerides (FFA: adipose tissue, liver)
3. Serum triglycerides (–>FFA)

Question 14

Fat can only be metabolized _______. It binds to _____ to be transported as FFA to cells. At the m. membrane, FFAs dissociate and crosse the membrane via_______. They enter the cytoplasm, FFA 70% is bound and transported by _____ and 30% move into mitochondria by ______.

Answer 14

Aerobically; albumin; lipoprotein lipase; carnitine; diffusion

Question 15

Where is glucose-6-phosphatase located and what is the importance of this?

Answer 15

Liver; It is only located in the liver and breaks down glycogen to be made into glucose; it is only located in the liver, so once glucose is transferred into other tissues, it is locked in and cannot be transported thought the body in the blood