Question

Question 2

Enzymes basically work by...

	A.	Directly providing ATP for muscle contraction
	B.	Lowering the activation energy required to drive the reaction
	C.	Combining with NAD+ to provide energy
	D.	Helping oxygen attach to substrate during metabolism
	E.	Both A and B

Anaerobic glycolysis yields a net gain of...

		5 ATP
		10 ATP
		8 ATP
		2 ATP

After a few minutes of easy jogging at a submaximal intensity, my oxygen consumption and heart rate reach a plateau and stay at that level for 20 to 30 minutes as I am jogging. With regards to oxygen consumption this would be an example of ...

	A.	intermittent exercise
	B.	an oxygen deficit
	C.	incremental exercise
	D.	a steady state
	E.	homeostasis

Question 17

The RQ measured for a subject who has been jogging easily at 70% VO2max for about 40 minutes and is in a steady state will likely be?

	A.	over 1.0
	B.	close to .7
	C.	close to .5
	D.	close to .9

Question 57

A person exercises in their “fat burning zone” for 4 hours at 35% VO₂peak. The O₂ cost of exercise at that work rate is 0.5L/minute. Following exercise the subject rewards himself with an ice-cream sundae (700kcal). The following statement is true(assume 5kcal/lit of O₂):

	A.	The subject is in neutral energy balance
	B.	The subject consumed fewer calories than they expended during exercise
	C.	The subject consumed more calories than they expended during exercise
	D.	Can’t say

Answer 1

1. Enzymes basically work by B. Lowering the activation energy required to drive the reaction.

Explaination: Basically enzymes work by attaching the substrate onto the active site of the enzyme. Then, the enzyme breaks some of the bonds within the substrate making it have weaker bonds. These weaker bonds are easier to be acted with and upon thus requiring less energy i.e. ATP. Thus, the enzyme works by lowering the amount of activation energy i.e. at a low ATP cost. 2. Anaerobic glycolysis yields a net gain of D. 2 ATP. Explaination: Anaerobic glycolysis is the trnasformation of glucose to lactate when limited amount of oxygen is available. Anaerobic glycolysis is only an effective means of energy production during short, intense exercise providing energy for a period ranging form 10 seconds to 2 minutes. It replenishes very quickly and produces 2 ATP molecules per glucose molecule. 3. After a few minutes of easy jogging at a submaximal intensity, my oxygen consumption and heart rate reach a plateau and stay at that level for 20 to 30 minutes as I am jogging. With regards to oxygen consumption this would be an example of D. a steady state. Explaination: As, the exerciser maintains a plateue phase during jogging for about 20 to 30 minutes, he or she is in a steady state for the oxygen consumption. A steady state is an unvarying condition in a physical process especially as in the theory that the universe is eternal and maintained by constant creation of matter. The RQ measured for a subject who has been jogging easily at 70% VO2max for about 40 minutes and is in a steady state will likely be D. close to 0.9. Explaination: A respiratory quotient i.e. RQ during a steady state exercise is suggested to be close to 0.95 where ther is a high rate of carbohydrate metabolism.