Energy Sources for Contraction

Question 1

ATP molecules

Answer 1

supply the energy for muscle fiber contraction

a muscle fiber has only enough ATP to contract for a very short time (1-2 seconds), so when a fiber is active, ATP must be regenerated

Question 2

creatine phosphate

Answer 2

The initial source for energy available to regenerate ATP from ADP and phosphate

contains high-energy phosphate bonds, and it is 3-6 times more abundant in muscle fibers than ATP

Question 3

Creatine

Answer 3

small amino-acid like molecule synthesized in the liver, pancreas, and kidneys and transported to the muscle

Question 4

creatine phosphate

Answer 4

a high energy compound

At rest, skeletal muscles produce more ATP than it needs. Under these conditions, ATP transfers energy to creatine.

Question 5

creatine phosphokinase

Answer 5

an enzyme in the mitochondria

promotes the synthesis of creatine phosphate

Question 6

phosphate bonds

Answer 6

stores excess energy

energy is good for only a few seconds (3-15 seconds) of maximal activity

Question 7

creatine kinase/creatine phosphokinase

Answer 7

catalyzes the transfer of one of the high-energy phosphate groups from ATP to creatine forming creatine phosphate and ADP.

Creatine phosphate becomes creatine when its energy is “given” to ADP.

Question 8

phosphorylation

Answer 8

the process of attaching a phosphate group to a compound