Online Quiz Questions

Question 1

The chemical behavior of an atom is primarily due to

Answer 1

the number of electrons in the highest energy shell.

Question 2

If the intracellular pH of a cell would increase from normal pH 7.2 to pH 9.0, what would you expect to happen to the carboxyl groups on all the proteins?

Answer 2

Mosts of the carboxyl groups would gain a H+ and have a net positive charge.

Question 3

What unit of length would you generally use to measure a typical plant or animal cell?

Answer 3

micrometer

Question 4

If two atoms that form a covalent bond have electronegativity numbers of 2.0 and 1.9, what can you predict about the nature of this covalent bond?

Answer 4

It will be a nonpolar covalent bond

Question 5

The diversity of cell types (their shape, function, etc) in a particular organism is due primarily to

Answer 5

Differential gene expression and unique proteins types being made in each cell type.

Question 6

Which of the following characteristics would be expected for hydrophobic molecules? a)They are polar molecules. b)They contain C-H covalent bonds. c)They usually hydrogen bond with water. d) Hydrophobic molecules tend to interact with one another in water.

Answer 6

They contain C-H covalent bonds. Hydrophobic molecules tend to interact with one another in water.

Question 7

T or F: The hydrogen atom involved in the hydrogen bond is negatively charged.

Answer 7

False

Question 8

Which of the following is found in BOTH an animal and plant cell? a)endoplasmic reticulum b)chloroplast c)cell wall d)mitochondria

Answer 8

endoplasmic reticulum mitochondria

Question 9

T or F: Electrostatic interactions are relatively strong interactions that can not easily be broken

Answer 9

False

Question 10

T or F: Electrostatic or ionic interactions involve actual attraction of a negative to a positive charge.

Answer 10

True

Question 11

T or F: Hydrogen bonding within a polypeptide chain can take place between molecules in a peptide bond and the R group of another amino acid.

Answer 11

True

Question 12

T or F: Two polypeptides with the exact same numbers and types of amino acids can have very different structures.

Answer 12

True

Question 13

In a nucleotide (or nucleoside) the bond between the ribose sugar and the organic base always involves what atom in the organic base?

Answer 13

nitrogen

Question 14

The correct name for the nucleotide dCDP is what?

Answer 14

deoxycytidine diphosphate

Question 15

How do the nonpolar amino acids in the polypeptide chain contribute to the tertiary (3-D) structure of the polypeptide?

Answer 15

The nonpolar R groups of these amino acids move to the interior of the polypeptide as it folds up.

Question 16

Consider the amino acid shown below. Which of the following interactions is likely to be involved between the R group of this amino acid and other molecules?

covalent

hydrophobic

ionic

wan der Waals

disulfide

Answer 16

ionic

Question 17

After formation of a peptide bond, what molecule is given off in the reaction?

Answer 17

water

Question 18

T or F: The flexibility of the polypeptide is due to the free rotation of the peptide bond.

Answer 18

False

Question 19

T or F: If a lysine is numbered 57 and a glycine is numbered 157 in the polypeptide chain, then the glycine is nearer to the carboxyl (or C) terminus of the polypeptide.

Answer 19

True

Question 20

T or F: The AA sequence TAQKDPSN is likely to be found on the outside of a polypeptide tertiary (3-D) structure

Answer 20

True

Question 21

Free energy or ∆G is a measure of the change in a chemical conversion that includes the

Answer 21

a. change in potential energy or useable energy in chemical bonds
b. change in disorder

Question 22

The standard ∆G° of a chemical reaction can be altered by a number of factors. Which one of the following is used to alter the ∆G° in a cell?

a. change pH
b. change temperature
c. change concentration of reactant and products
d. add an enzyme
e. change pressure

Answer 22

change concentration of reactant and products

Question 23

The role of enzymes in biological chemical reaction is to

Answer 23

reduce the activation energy.

Question 24

Proteins function by binding specific molecules called “ligands.” These can be other proteins, small organic molecules, or even DNA. What ultimately determines why protein-ligand binding is very specific. That is, why do proteins only recognize and bind one other molecule?

Answer 24

Because of the protein’s primary structure, which determines its overall tertiary structure and possibly quaternary interactions.

Question 25

At first glance, it may seem that living systems are able to defy the second law of thermodynamics. However, on closer examination, it becomes clear that although cells create organization from raw materials in the environment, they also contribute to disorder in the environment by releasing _____________.

Answer 25

heat

Question 26

Enzymes function similar to all proteins. The ligand binding to an enzyme is called the _____________________ and it binds to the ____________________ of the enzyme.

Answer 26

substrate; active site