Chapter 1 Practice Problems

Question 1

What group of single-celled microorganisms have many members found growing in extreme environments?

Eukaryotes, Archaea, Heterotrophs, Bacteria

Answer 1

Archaea

Question 2

The enzyme fumarase catalyzes the reversible hydration of fumaric acid to I-malate, but it will not catalyze the hydration of maleic acid, the cis isomer of fumaric acid. This is an example of:

Biological activity
Stereospecificity
Chiral activity
Stereoisomerization
Racemization

Answer 2

Stereospecificity

Question 3

If the free energy change (delta G) for a reaction is -46.11 kJ/mol, the reaction is

Exothermic
Endergonic
At equilibrium
Endothermic
Exergonic

Answer 3

Exergonic

Question 4

According to Oparin’s theory for the origin of life, the prebiotic atmosphere:

contained many amino acids
had an abundance of methane, ammonia, and water
was rich in oxygen
already contained some primitive RNA molecules
basically was very similar to the atmosphere today

Answer 4

had an abundance of methane, ammonia, and water

Question 5

The major carrier of chemical energy in a cell is

adenosine triphosphate
cytosine tetraphosphate
adenosine monophosphate
uridine diphosphate
acetyl triphosphate

Answer 5

adenosine triphosphate

Question 6

Stereoisomers that are non-superimposable mirror images of each other are known as:

geometric isomers
cis-trans isomers
diastereoisomer
enantiomers
anomers

Answer 6

enantiomers

Question 7

Use the terms a.) chemoautotrophs, b.) chemoheterotrophs, c.) photoautotrophs, and d,) photoheterotrophs and identify the answer that correctly finishes the statement:

Carnivores are ____ and herbivores are ___

Answer 7

b, b

Question 8

If heat energy is absorbed by the system during a chemical reaction, the reaction is said to be:

at equilibrium
exothermic
endothermic
exergonic
endergonic

Answer 8

endothermic

Question 9

Enzymes are biological catalysts that enhance the rate of a reaction by

decreasing the activation energy
decreasing the amount of free energy released
increasing the energy of the transition state
increasing the activation energy
increasing the amount of free energy

Answer 9

decreasing the activation energy

Question 10

A major change occurring in the evolution of eukaryotes from prokaryotes was the development of:

ribosomes
DNA
the nucleus
photosynthetic capability
plasma membranes

Answer 10

the nucleus

Question 11

The macromolecules that serve in the storage and transmission of genetic information are

nucleic acids
lipids
proteins
membranes
carbohydrates

Answer 11

nucleic acids

Question 12

The three-dimensional structure of a protein is determined primarily by

modification during interactions with ribosomes
the sequence of amino acids in the protein
electrostatic guidance from nucleic acid structure
hydrophobic interactions with lipids that provide a folding framework
how many amino acids are in the protein

Answer 12

the sequence of amino acids in the protein

Question 13

The bacterium E. coli requires simple organic molecules for growth and energy– it is therefore a

chemoheterotroph
photoautotroph
chemoautotroph
lithotroph
photoheterotroph

Answer 13

chemoheterotroph

Question 14

What functional groups are present on this molecule?
HO-CH2-CH2-CH=O

Ether and aldehyde
Hydroxyl and ketone
Hydroxyl and carboxylic acid
Hydroxyl and aldehyde
Hydroxyl and ester

Answer 14

Hydroxyl and aldehyde