Biology, Eighth Edition (Raven)

Chapter 48: The Digestive System

B Vitamins

What is the role of vitamins in human nutrition? Vitamins are cofactors to enzymes. They interact with enzymes to allow the enzymes to function more effectively. Vitamins are not consumed in metabolism but are vital for in the process of metabolism. Humans lack the ability to synthesize many vitamins and need to get them in our diet. Scurvy is a disease caused by a deficiency of vitamin C. Sailors on long voyages were prone to scurvy because they were unable to get fresh fruits and vegetables on the open ocean. Once it was realized that diet was responsible for scurvy it was largely eliminated as a health problem.

View the animation below, then complete the quiz to test your knowledge of the concept.


1.	What function do many B vitamins serve in the production of energy?

		A)	they function as enzymes
		B)	they function as co-enzymes
		C)	they function as energy sources
		D)	they function as hypoenzymes

2.	Enzymes assist in the occurrence of reactions by

		A)	lowering of activation energy.
		B)	raising of activation energy.
		C)	providing ATP.
		D)	using ATP.

3.	In the example shown, what co-enzyme is used to assist in the production of ATP from pyruvate?

		A)	green co-factor
		B)	carbon dioxide
		C)	thiamine pyrophosphate
		D)	an apoenzyme

4.	Consuming B vitamins in excess of need will

		A)	decrease formation of energy (ATP).
		B)	increase formation of energy (ATP).
		C)	increase rate of muscle formation.
		D)	increase B vitamins in urine.

5.	Which B vitamin is found in egg yolk (and other foods) and functions as part of Coenzyme A?

		A)	riboflavin
		B)	niacin
		C)	pantothenic acid
		D)	biotin