Question 1

Which of the following is considered a metabolite,a substance that is chemically transformed in a biochemical process?
A) deoxyribonucleic acid
B) glycerol
C) protein
D) ribonucleic acid
E) polysaccharide

Accepted Answer

Glycerol is a substance that can be chemically transformed in biochemical processes. DNA, RNA, protein, and polysaccharides are not considered metabolites as they do not undergo chemical transformation in biochemical processes.

Question 2

The matter within a defined region of space is referred to as the _____.
A) universe
B) system
C) outer space
D) wormhole
E) None of the answers is correct.

Accepted Answer

Within the context of scientific or engineering disciplines, a defined region of space is typically referred to as a system. The universe refers to all matter and energy, while outer space refers to the vast expanse beyond the Earth's atmosphere. A wormhole is a hypothetical shortcut through spacetime that is not a physical region of space in the same sense as a system.

Question 3

Which of the following are the strongest bonds in molecules?
A) covalent bonds
B) ionic bonds
C) hydrogen bonds
D) metallic bonds
E) None of the answers is correct.

Accepted Answer

Covalent bonds are the strongest bonds in molecules because they involve the sharing of electrons between atoms, which holds the atoms together tightly. Ionic bonds are also strong, but they involve the transfer of electrons rather than sharing. Hydrogen bonds are weaker and are formed between molecules rather than within a single molecule. Metallic bonds are the weakest of the listed bonds and are only found in metals where electrons are shared among a sea of atoms.

Question 4

If the whole chain is used in a nonoverlapping frame,how many amino acids are defined by this DNA sequence: ATGTTTGGACTA?
A) two
B) three
C) four
D) six
E) twelve

Accepted Answer

The answer of If the whole chain is used in...

Question 5

The fundamental groups of organisms include Eukarya,Bacteria,and _____.
A) Plantae
B) Animalia
C) Protista
D) Archaea
E) Fungi

Accepted Answer

The three fundamental groups of organisms are Eukarya, Bacteria, and Archaea. Plantae, Animalia, Protista, and Fungi are subgroups of Eukarya.

Question 6

The term _____ is used to indicate Gibbs free energy.
A) $\Delta$H
B) $\Delta$E
C) $\Delta$S
D)$\Delta$G
E) $\Delta$T

Accepted Answer

The letter G typically represents Gibbs free energy, therefore choice D is the correct option.

Question 7

The number of hydrogen bonds formed between G and C is _____.
A) 1
B) 2
C) 3
D) 4
E) 2 if in RNA, 3 if in DNA

Accepted Answer

Guanine (G) and Cytosine (C) form three hydrogen bonds when they pair together in both DNA and RNA.

Question 8

DNA is made from the building blocks adenine,guanine,cytosine and _____.
A) uridine
B) thymine
C) inosine
D) ribose
E) None of the answers is correct.

Accepted Answer

DNA is made up of four nucleotides: adenine, guanine, cytosine, and thymine.

Question 9

What is the [H⁺] concentration in a urine sample that has a pH of 6? A) 10^-⁶ M B) 10^-⁸ M C) 10⁶ M D) 10^-¹⁴ M E) 6 M

Accepted Answer

The concentration of hydrogen ions [H+] in a solution with a pH of 6 is calculated using the formula [H+] = 10^-pH. Therefore, for a pH of 6, the concentration is 10^-6 M.

Question 10

What gives proteins such a dominant role in biochemistry?
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.

Accepted Answer

Proteins have a dominant role in biochemistry due to their ability to spontaneously fold into complex three-dimensional structures. This ability allows them to perform a wide variety of functions, including catalyzing biochemical reactions, transporting molecules, and providing structural support. Additionally, their diverse amino acid sequence allows for a huge range of possible structures and functions, making them incredibly versatile in biological systems.

Question 11

Which is the correct order of decreasing bond strengths?
A) hydrogen bonds, covalent bonds, van der Waals interactions
B) hydrogen bonds, electrostatic interactions, covalent bonds
C) van der Waals interactions, covalent bonds, hydrogen bonds
D) covalent bonds, hydrogen bonds, van der Waals interactions
E) hydrophobic interactions, hydrogen bonds, electrostatic interactions

Accepted Answer

Covalent bonds have the highest bond strength, followed by hydrogen bonds, and then van der Waals interactions. Electrostatic interactions and hydrophobic interactions are not included in the given choices.

Question 12

Which of the following is a hydrogen bond donor?
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.

Accepted Answer

A hydrogen bond donor is a molecule or functional group that has a hydrogen atom bonded to an electronegative atom such as N, O or F. In this case, the only option with a hydrogen atom bonded to an electronegative O atom is D) the H in O-H.

Question 13

The number of hydrogen bonds formed between A and T is _____.
A) 1
B) 2
C) 3
D) 4
E) 2 if in DNA, 3 if in RNA

Accepted Answer

A and T form two hydrogen bonds with each other in a DNA molecule.

Question 14

Which of the following describes the relationship between the strengths of hydrogen and covalent 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.

Accepted Answer

The answer of Which of the following describes the relationship...

Question 15

The DNA backbone is made from repeating _____.
A) monosaccharide units
B) amino acid units
C) sugar-phosphate units
D) fatty acid
E) None of the answers is correct.

Accepted Answer

The DNA backbone is made up of a repeating pattern of sugar (deoxyribose) and phosphate groups. This sugar-phosphate backbone forms the structural framework for the double helix of DNA.

Question 16

What did Watson and Crick suggest to be significant about the base pairing found in the helix?
A) It allowed the DNA to twist in a helix.
B) The DNA could be circular.
C) It was a mechanism for copying.
D) All of the answers are correct.
E) None of the answers is correct.

Accepted Answer

Watson and Crick suggested that the base pairing found in the helix was a mechanism for copying, which is the process of DNA replication. This is significant because it allows cells to divide and pass on genetic information to their daughter cells with very high accuracy. The complementary base pairing ensures that each strand serves as a template for the synthesis of a new, complementary strand, resulting in two identical copies of the original DNA molecule.

Question 17

The energies for hydrogen bonds are approximately A) 400 kJ mol^-1. B) 100-240 kJ mol^-¹. C) 4-20 kJ mol^-¹. D) 200 kJ mol^-¹. E) None of the answers is correct.

Accepted Answer

Hydrogen bonds are relatively weak interactions compared to covalent bonds, with energies typically in the range of 4-20 kJ/mol.

Question 18

Approximately what percentage of the human genome encodes proteins?
A) 50%
B) 90%
C) 20%
D) 3%
E) None of the answers is correct.

Accepted Answer

Only about 2-3% of the human genome encodes for proteins. The rest of the genome is made up of non-coding DNA, regulatory elements, and repetitive sequences.

Question 19

The structure of DNA described by Watson and Crick included
A) a double helix.
B) the sugar phosphate backbone aligned in the center of the helix.
C) the base pairs that are stacked on the inside of the double helix.
D) both a double helix and the sugar phosphate backbone aligned in the center of the helix
E) a double helix and the base pairs that are stacked on the inside of the double helix

Accepted Answer

The structure of DNA described by Watson and Crick includes a double helix with the base pairs stacked on the inside, while the sugar-phosphate backbone is on the outside of the helix, not the center.

Question 20

For a spontaneous reaction,the $\Delta$G must be _____.
A) positive
B) negative
C) greater than 1
D) between 1 and 0
E) 0

Accepted Answer

A spontaneous reaction has a negative Gibbs free energy change (ΔG) value. ΔG can be calculated using the formula ΔG = ΔH - TΔS, where ΔH is the change in enthalpy, T is the temperature in Kelvin, and ΔS is the change in entropy. If ΔG is negative, then F1F1F1S1 must have a higher Gibbs free energy than F1F1F10G for the reaction to proceed spontaneously. This means that F1F1F1S1F1F1F10G has a negative value, making B the correct answer.

Quiz 1: Biochemistry: An Evolving Science

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

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

Which of the following are the strongest bonds in molecules?

If the whole chain is used in a nonoverlapping frame,how many amino acids are defined by this DNA sequence: ATGTTTGGACTA?

The fundamental groups of organisms include Eukarya,Bacteria,and _____.

The term _____ is used to indicate Gibbs free energy.

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

DNA is made from the building blocks adenine,guanine,cytosine and _____.

What is the [H⁺] concentration in a urine sample that has a pH of 6?

What gives proteins such a dominant role in biochemistry?

Which is the correct order of decreasing bond strengths?

Which of the following is a hydrogen bond donor?

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

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

The DNA backbone is made from repeating _____.

What did Watson and Crick suggest to be significant about the base pairing found in the helix?

The energies for hydrogen bonds are approximately

Approximately what percentage of the human genome encodes proteins?

The structure of DNA described by Watson and Crick included

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