Deck 2: Chemistry of Life

Question 1

The disease called sickle-cell anemia is caused by a change in a single amino acid residue in the hemoglobin protein, resulting in a distortion of the protein's shape at which levels?

A)primary and quaternary
B)primary and secondary
C)secondary and tertiary

Answer 1

B

Question 2

A team of researchers is investigating a new carbon-rich molecule important to life.They find evidence for the presence of both cis and trans isomers of the molecule in a mixture of near-pure molecules.Which of the following must be contained in the new molecule?

A)a double bond
B)an aliphatic hydrocarbon
C)a hydrocarbon ring structure

Answer 2

A

Question 3

How did the hydrocarbons found in petroleum products such as gasoline get their energy?

A)from the decay of non-living substances
B)from fossilized molecules built up in previously existing living organisms
C)from kinetic energy

Answer 3

B

Question 4

Water molecules have one oxygen atom that is more electronegative than the two hydrogen atoms bound to it.As a result, which type of bonding holds water molecules together?

A)non-polar covalent bonding
B)polar covalent bonding
C)ionic bonding

Question 5

A biologist isolates a large, unidentified molecule from some cells in his lab.What type of reaction could he initiate to determine whether the molecule is a polymer and, thus, a macromolecule?

A)condensation
B)dehydration
C)hydrolysis

Question 6

Why are humans unable to digest cellulose?

A)Cellulose is made of glucose molecules connected by β 1-4 glycosidic linkages.
B)Cellulose is made of glucose molecules connected by α 1-4 glycosidic linkages.
C)Cellulose is made of glucose molecules connected by α 1-6 glycosidic linkages.

Question 7

A biochemist is analyzing an aqueous solution of a pure unidentified macromolecule that she isolated from the cytosolic fraction of plant cells.She determined that the macromolecule is probably DNA from chloroplasts and mitochondria by adding an enzyme that catalyzed the destruction of the macromolecule.The enzyme most likely broke which type of bonds?

A)glycosidic
B)peptide
C)phosphodiester

Question 8

Which of the following macromolecules are made from simple sugars?

A)proteins
B)complex carbohydrates
C)nucleic acids

Question 9

The "backbones" of the macromolecules of life made of what element?

A)carbon
B)nitrogen
C)oxygen

Question 10

Which of the following macromolecules are made from amino acids?

A)proteins
B)complex carbohydrates
C)nucleic acids

Question 11

Which of the following macromolecules are associated with RNA and DNA?

A)proteins
B)complex carbohydrates
C)nucleic acids

Question 12

A team of researchers is investigating a new carbon-rich molecule important to life.They find evidence for the presence of a carbon-carbon double bond in the molecule.This observation means that the new molecule likely exists as which of following?

A)a hydrocarbon ring
B)both cis and trans isomers
C)an aliphatic hydrocarbon

Question 13

Consider the following chemical equation which depicts the mechanism by which humans maintain an acid-base balance in the blood: H⁺ + HCO₃^- ↔ H₂CO₃ ↔ H₂0 + CO₂
What happens if the carbon dioxide on the right is not removed from the blood via the lungs?

A)The reaction will be driven toward the left, resulting in the blood becoming more acidic.
B)The reaction will be driven toward the left, resulting in the blood becoming more basic.
C)The reaction will be driven toward the center, and the pH of the blood will remain neutral.

Question 14

Which of the following elements is not particularly associated with living things?

A)nitrogen
B)silicon
C)oxygen

Question 15

A biologist isolates a large, unidentified molecule from some cells in his lab.He determines that the macromolecule breaks into smaller pieces with the concomitant loss of water.What reaction has he observed?

A)hydrolysis
B)condensation
C)dehydration

Question 16

Consider the following chemical equation which depicts the mechanism by which humans maintain an acid-base balance in the blood: H⁺ + HCO₃^- ↔ H₂CO₃ ↔ H₂0 + CO₂
What happens in this reaction if the blood becomes more acidic, and what is the physiological response?

A)The reaction will be driven toward the left, and the blood will become more basic.
B)The reaction will be driven toward the right, and more CO₂ will be removed via exhalation.
C)The reaction will be driven toward the center, and the pH of the blood will remain neutral.

Question 17

A molecule with more than one type of elements is known as a:

A)macromolecule
B)protein
C)compound

Question 18

Why are amino acids called "amino acids?"

A)They are single molecules that contain both an amine group and a carboxylic acid group.
B)They are subunits of macromolecules that act as both strong acids and strong bases in solution.
C)They are acidic and were first discovered by a Russian researcher by the name of Aminov.

Question 19

A biochemist is analyzing an aqueous solution of a pure unidentified macromolecule that she isolated from the cytosolic fraction of plant cells.After adding an enzyme that catalyzes the breaking of phosphodiester bonds, she observes that the macromolecule disappears.What is the most likely explanation?

A)The macromolecule was a polysaccharide from the cell wall.
B)The macromolecule was DNA from the chloroplast and mitochondria.
C)The macromolecule was a protein from the cytosol.

Question 20

Which of the following statements correctly identifies and describes the type of covalent bond found between oxygen and hydrogen in water molecules?

A)polar covalent bonds because hydrogen is more electronegative than oxygen
B)hydrogen bonds because hydrogen is more electronegative than oxygen
C)polar covalent bonds because oxygen is more electronegative than hydrogen

Question 21

The chemical bond between amino acids is called a _______ bond.(Outcome #1)

A)phosphodiester
B)hydrogen
C)peptide

Question 22

The chemical group on an amino acid that distinguishes one form another is known as the:

A)R group
B)P group
C)C group

Question 23

Proteins with more than one polypeptide chain are said to have a ______ structure.(Outcome #1)

A)quaternary
B)secondary
C)tertiary

Question 24

Which of the following is not a component of a nucleotide?

A)nitrogenous base
B)fatty acid
C)sugar

Question 25

Atoms that gain or lose electrons are known as:

A)elements
B)molecules
C)ions

Question 26

Why does heating up a protein such as an enzyme cause it to lose function?

A)because it burns up
B)because it loses its shape
C)because it works best at low temperatures

Question 27

What level of protein structure is associated with the sequence of amino acids?

A)primary
B)secondary
C)tertiary

Question 28

Fatty acids are a component of what type of macromolecule?

A)lipids
B)complex carbohydrates
C)nucleic acids

Question 29

What type of chemical bond stabilizes crystals of table salt?

A)covalent bonds
B)ionic bonds
C)hydrogen bonds

Question 30

What level of protein structure is associated the alpha helix and beta-pleated sheet?

A)primary
B)secondary
C)tertiary

Question 31

What type of chemical bond stabilizes the 3 dimensional shapes of nucleic acids and proteins:

A)covalent bonds
B)ionic bonds
C)hydrogen bonds

Question 32

Explain why cooked egg white never turns back into the clear egg white seen in a raw egg.(Outcome #1)

A)because the protein is denatured in raw egg white
B)because the protein is denatured in cooked egg white
C)because the denaturing of the egg proteins is not reversible

Question 33

Water molecules attract one another via:

A)covalent bonds
B)ionic bonds
C)hydrogen bonds