Question 1

Describe the shape of methane.

Accepted Answer

Methane is tetrahedral, with bond angles of about 109°.

Question 2

If the First Law of Thermodynamics is true, how can biological processes be carried out?

Accepted Answer

Although energy cannot be created or destroyed, it can take on different forms, such as heat or chemical energy. Thus, the energy can be stored as chemical bond energy, which can be used to do work.

Question 3

Which of the following are the strongest bonds in molecules?

Accepted Answer

A)  covalent bonds 
B)  ionic bonds 
C)  hydrogen bonds 
D)  metallic bonds 
E)  None of the answers is correct. 
A)  covalent bonds 
B)  ionic bonds 
C)  hydrogen bonds 
D)  metallic bonds 
E)  None of the answers is correct. A

Question 4

How are electrostatic forces used in protein folding?

Accepted Answer

The attraction of two opposite

Question 5

Typical van der Waals energies are about

Accepted Answer

A)  4-20 kJ mol-1. 
B)  2-4 kJ mol-1. 
C)  200 kJ mol-1. 
D)  500-1000 kJ mol-1. 
E)  None of the answers is correct. 
A)  4-20 kJ mol-1. 
B)  2-4 kJ mol-1. 
C)  200 kJ mol-1. 
D)  500-1000 kJ mol-1. 
E)  None of the answers is correct.

Question 6

What is significant about the fact that metabolic processes are common to many organisms?

Accepted Answer

These metabolic proc

Question 7

Which of the following is considered a metabolite, a substance that is chemically transformed in a biochemical process?

Accepted Answer

A)  deoxyribonucleic acid 
B)  glycerol 
C)  protein 
D)  ribonucleic acid 
E)  polysaccharide 
A)  deoxyribonucleic acid 
B)  glycerol 
C)  protein 
D)  ribonucleic acid 
E)  polysaccharide

Question 8

What gives proteins such a dominant role in biochemistry?

Accepted Answer

A)  the rigidity of the peptide backbone 
B)  the ability to act as a blueprint 
C)  the ability to self-replicate 
D)  the ability to spontaneously fold into complex three-dimensional structures 
E)  All of the answers are correct. 
A)  the rigidity of the peptide backbone 
B)  the ability to act as a blueprint 
C)  the ability to self-replicate 
D)  the ability to spontaneously fold into complex three-dimensional structures 
E)  All of the answers are correct.

Question 9

Which of the following describes the relationship between the strengths of hydrogen and covalent bonds?

Accepted Answer

A)  Hydrogen bonds are always stronger than covalent bonds. 
B)  Hydrogen bonds and covalent bonds have equivalent strength. 
C)  Hydrogen bonds are always weaker than covalent bonds. 
D)  With a few exceptions, most hydrogen bonds are stronger than covalent bonds. 
E)  With a few exceptions, most covalent bonds are stronger than hydrogen bonds. 
A)  Hydrogen bonds are always stronger than covalent bonds. 
B)  Hydrogen bonds and covalent bonds have equivalent strength. 
C)  Hydrogen bonds are always weaker than covalent bonds. 
D)  With a few exceptions, most hydrogen bonds are stronger than covalent bonds. 
E)  With a few exceptions, most covalent bonds are stronger than hydrogen bonds.

Question 10

What are the primary chemical components present in a phosphate buffer at pH 7.4?

Accepted Answer

A)  H3PO4 and PO43- 
B)  H2PO4- and PO43- 
C)  HPO42- and PO43- 
D)  H2PO4- and HPO42- 
E)  H3PO4 and HPO42- 
A)  H3PO4 and PO43- 
B)  H2PO4- and PO43- 
C)  HPO42- and PO43- 
D)  H2PO4- and HPO42- 
E)  H3PO4 and HPO42-

Question 11

Which of the following is a hydrogen bond donor?

Accepted Answer

A)  the N in N-H D 
B)  the H in S-H 
C)  the O in P-O 
D)  the H in O-H 
E)  None of the answers is correct. 
A)  the N in N-H D 
B)  the H in S-H 
C)  the O in P-O 
D)  the H in O-H 
E)  None of the answers is correct.

Question 12

For a spontaneous reaction, the $\Delta$G must be _____.

Accepted Answer

A)  positive 
B)  negative 
C)  greater than 1 
D)  between 1 and 0 
E)  0 
A)  positive 
B)  negative 
C)  greater than 1 
D)  between 1 and 0 
E)  0

Question 13

How is water able to be a solvent for so many biological molecules?

Accepted Answer

Many biological molecules have polar cha

Question 14

The number of hydrogen bonds formed between G and C is _____.

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  2 if in RNA, 3 if in DNA 
A)  1 
B)  2 
C)  3 
D)  4 
E)  2 if in RNA, 3 if in DNA

Question 15

The matter within a defined region of space is referred to as the _____.

Accepted Answer

A)  universe 
B)  system 
C)  outer space 
D)  wormhole 
E)  None of the answers is correct. 
A)  universe 
B)  system 
C)  outer space 
D)  wormhole 
E)  None of the answers is correct.

Question 16

What thermodynamic and free-energy changes participate in protein folding?

Accepted Answer

A combination of hydrogen bond

Question 17

The number of hydrogen bonds formed between A and T is _____.

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  2 if in DNA, 3 if in RNA 
A)  1 
B)  2 
C)  3 
D)  4 
E)  2 if in DNA, 3 if in RNA

Question 18

The DNA backbone is made from repeating _____.

Accepted Answer

A)  monosaccharide units 
B)  amino acid units 
C)  sugar-phosphate units 
D)  fatty acid 
E)  None of the answers is correct. 
A)  monosaccharide units 
B)  amino acid units 
C)  sugar-phosphate units 
D)  fatty acid 
E)  None of the answers is correct.

Question 19

What is the significance of hydrogen bonding in biochemical structures such as DNA?

Accepted Answer

The bonds are weak enough to b

Question 20

Using the Henderson-Hasselbalch equation, calculate the pH of a buffer solution made from 0.20 M CH3COOH and 0.050 M CH3COO- that has pKa= 4.7.

Accepted Answer

A)  5.3 
B)  4.1 
C)  2.5 
D)  0.4 
E)  None of the answers is correct. 
A)  5.3 
B)  4.1 
C)  2.5 
D)  0.4 
E)  None of the answers is correct.

Exam 1: Biochemistry: an Evolving Science

Describe the shape of methane.

If the First Law of Thermodynamics is true, how can biological processes be carried out?

Which of the following are the strongest bonds in molecules?

How are electrostatic forces used in protein folding?

Typical van der Waals energies are about

What is significant about the fact that metabolic processes are common to many organisms?

Which of the following is considered a metabolite, a substance that is chemically transformed in a biochemical process?

What gives proteins such a dominant role in biochemistry?

Which of the following describes the relationship between the strengths of hydrogen and covalent bonds?

What are the primary chemical components present in a phosphate buffer at pH 7.4?

Which of the following is a hydrogen bond donor?

For a spontaneous reaction, the Δ\DeltaΔ G must be _____.

How is water able to be a solvent for so many biological molecules?

The number of hydrogen bonds formed between G and C is _____.

The matter within a defined region of space is referred to as the _____.

What thermodynamic and free-energy changes participate in protein folding?

The number of hydrogen bonds formed between A and T is _____.

The DNA backbone is made from repeating _____.

What is the significance of hydrogen bonding in biochemical structures such as DNA?

Using the Henderson-Hasselbalch equation, calculate the pH of a buffer solution made from 0.20 M CH3COOH and 0.050 M CH3COO- that has pKa= 4.7.

Protein Composition and Structure

Exploring Proteins and Proteomes

DNA, RNA, and the Flow of Genetic Information

Exploring Genes and Genomes

Exploring Evolution and Bioinformatics

Hemoglobin: a Portrait of a Protein in Action

Enzymes: Basic Concepts and Kinetics

Oxidative Phosphorylation

Catalytic Strategies

Regulatory Strategies

Carbohydrates

Lipids and Cell Membranes

Membrane Channels and Pumps

Signal-Transduction Pathways

Metabolism: Basic Concepts and Design

Glycolysis and Gluconeogenesis

The Citric Acid Cycle

The Light Reactions of Photosynthesis

The Calvin Cycle and the Pentose Phosphate Pathway

Glycogen Metabolism

Fatty Acid Metabolism

Protein Turnover and Amino Acid Catabolism

The Biosynthesis of Amino Acids

Nucleotide Biosynthesis

Biosynthesis of Membrane Lipids and Steroids

The Integration of Metabolism

DNA Replication, Repair, and Recombination

Rna Synthesis and Processing

Protein Synthesis

The Control of Gene Expression in Prokaryotes

The Control of Gene Expression in Eukaryotes

Sensory Systems

The Immune System

Molecular Motors

Drug Development

Filters

For a spontaneous reaction, the $\Delta$ G must be _____.

Using the Henderson-Hasselbalch equation, calculate the pH of a buffer solution made from 0.20 M CH₃COOH and 0.050 M CH₃COO^- that has pK_a= 4.7.