CHAPTER ONE BIOCHEMISTRY: AN INTRODUCTION

CHAPTER ONE
BIOCHEMISTRY: AN INTRODUCTION
1) The ultimate source of energy for life on earth is __________.

A) The sun
B) Geothermal heat
C) Carbohydrates
D) Fats
E) Other organisms
Ans A


2) Which of the following is not a common component of biomolecules?

A) Carbon
B) Hydrogen
C) Oxygen
D) Nitrogen
E) Chlorine
Ans E


3) Which of the following is the basic structural unit of living organisms?

A) Nucleus
B) Cell membrane
C) Tissue
D) Cell
E) Cytoskeleton
Ans D


4) Which of the following is not an organelle?

A) Mitochondria
B) Chloroplast
C) Nucleus
D) Plasma membrane
E) Golgi complex
Ans D


5) Which of the following is not a role played by carbohydrates in living cells?

A) Energy source
B) Structural support
C) Intercellular communication

, D) Both A and B are correct
E) All are roles played by carbohydrates in living cells
Ans E


6) Metabolism is best defined as the _________.

A) Reactions of living cells
B) Reactions that synthesize large molecules in living cells
C) Reactions that degrade molecules in living cells
D) Conversion of food molecules to energy
E) Reactions that synthesize and degrade molecules in living cells
Ans E

7) The average life span of a species is about ________years

A)One million
B) Ten million
C) Five hundred thousand
D)Five million
E) One hundred thousand
Ans A


8) Which of the following is not a waste product of living organisms

A) Carbon dioxide
B) Water
C) Urea
D) Ammonia
E) Glycine
Ans E


9) Biochemistry is defined as

A) The study of life processes
B) The study of the molecular basis of life
C) The study of living organisms
D) The study of organic compounds in living organisms
E) The study of living compounds
Ans B


10) One of the principal methods that organisms use to obtain energy from chemical bonds is by ___________.

A) Substitution reactions
B) Dehydration reactions
C) Oxidation/reduction reactions

, D) Hydration reactions
E) Addition reactions
Ans C


11) The following is an example of which reaction class?

CH3Br + HSCH2CH(NH2)COOH → CH3SCH2CH(NH2)COOH + Br­ + H+

A) Substitution
B) Elimination
C) Addition
D) Isomerization
E) Oxidation/Reduction
Ans A


12) The following is an example of which reaction class

HOOCCH=CHCOOH + H2O → HOOCCH2CH(OH)COOH

A) Substitution
B) Elimination
C) Addition
D) Isomerization
E) Oxidation/Reduction
Ans C


13) The following is an example of which reaction class?

CH3CH2OH → CH3CHO + H2O

A) Substitution
B) Elimination
C) Addition
D) Isomerization
E) Oxidation/Reduction
Ans E


14) Which of the following is not a component of nucleic acid?

A) Nucleotides
B) Glucose
C) Phosphate group
D) Purines
E) Pyrimidines
Ans B

, 15) The largest molecules in living organisms are _________.

A) proteins
B) lipids
C) nucleic acids
D) carbohydrates
E) steroids
Ans C


16) All of the following classes of compounds are lipids except _______.

A) fats
B) sterols
C) fatty acids
D) phosphoglycerides
E) nucleotides
Ans E


17) Which of the following classes of biomolecules are the most abundant in nature?

A) Lipids
B) Amino acids
C) Carbohydrates
D) Proteins
E) Nucleotides
Ans C


18) Consider the following molecule. Which arrow is pointing to a peptide bond?




A) A