EXAM 1

Question 1

A reaction that has a negative ΔG

Answer 1

is spontaneous.

Question 2

Fatty acids are

Answer 2

carboxylic acids with long hydrocarbon tails.

Question 3

Oils and fats

Answer 3

are triglycerides

Question 4

Which of the following statements about starch is false?

Answer 4

The properties of starch are very similar to those of cellulose.

Question 5

The synthesis of complex molecules _______ energy, whereas their degradation _______ energy. Synthesis occurs with _______ in entropy.

Answer 5

requires; releases; a decrease

Question 6

A phospholipid differs from a triglyceride in that phospholipids

Answer 6

are amphipathic.

Question 7

Which of the following biological molecules are linked by covalent bonds formed by the removal of the elements of water from the reactants (a kind of condensation reaction)?

Answer 7

Oils
Fats
Proteins
Starch

Question 8

The “building blocks” of polysaccharides are _______, and the blocks are covalently linked together by _______.

Answer 8

monosaccharides; glycosidic linkages

Question 9

The stability of the three-dimensional shape of many large molecules is dependent on

Answer 9

hydrogen bonds.

Question 10

Which of the following statements about chemical reactions is true?

Answer 10

The bonding partners of atoms change.

Question 11

Which of the following is not a polymer?

Answer 11

A lipid

Question 12

Cellulose and starch are composed of the same monomers but have structural and functional differences. Which of the following is the characteristic that accounts for those differences?

Answer 12

Different types of glycosidic linkages

Question 13

Which of the following statements concerning energy transformations is true?

Answer 13

Increases in entropy reduce usable energy.

Question 14

Which of the following physiological functions is not usually served by proteins?

Answer 14

Energy reserve

Question 15

Quaternary structure of proteins refers to

Answer 15

the number and kind of polypeptide subunits the protein has.

Question 16

Replication, transcription, and translation

Answer 16

ll refer to the synthesis of macromolecules.

Question 17

If rainbow trout were transferred from warm water to near freezing water (2°C), what changes in the trout would occur in the trout’s nervous system in the colder water?

Answer 17

The trout would produce a new isozyme of acetylcholinesterase that has a lower optimal temperature, allowing the fish’s nervous system to perform normally in the colder water.

Question 18

Which of the following functional groups is not found in an R group of the protein amino acids?

Answer 18

—CHO

Question 19

DNA with a higher G + C content is more stable at high temperatures than DNA with a high A + T content. Why?

Answer 19

G and C form three hydrogen bonds between antiparallel strands and A and T, just two.

Question 20

Coenzymes differ from enzymes in that coenzymes

Answer 20

bind to the active site.

Question 21

The extracellular matrix of animal cells

Answer 21

helps orient cell movements during embryonic development.

Question 22

Amoeba proteus is injected with a drug that inhibits the formation of microtubules. What effect does this have on the organism’s movement?

Answer 22

It continues to move with no effect.

Question 23

Some proteins that are on the surface of mammalian cells contain carbohydrates.
These proteins are synthesized by _______ and the sugars added in the _______.

Answer 23

the rough endoplasmic reticulum; Golgi apparatus

Question 24

Which of the following structures is/are involved with maintaining the position of the organelles within a cell?

Answer 24

Intermediate filaments

Question 25

The extracellular matrix of animal cells

Answer 25

helps orient cell movements during embryonic development.

Question 26

Ribosomes are made up of

Answer 26

RNA and proteins

Question 27

What is the difference between “free” ribosomes and “attached” ribosomes?

Answer 27

Free ribosomes are in the cytoplasm, whereas attached ribosomes are anchored to the endoplasmic reticulum.
Free ribosomes produce proteins in the cytosol, whereas attached ribosomes produce proteins that are inserted into the ER.

Question 28

Steroids such as cholesterol are synthesized by

Answer 28

the smooth ER.

Question 29

Lysosomes are important to eukaryotic cells because they contain

Answer 29

digestive enzymes.

Question 30

Which group is typically added by a covalent bond to an enzyme as a means of allosteric regulation?

Answer 30

Phosphate