Chapters 5 and 6

Question 1

Which of the following is not a polymer?

a. glucose
b. starch
c. cellulose
d. chitin
e. DNA

Answer 1

Glucose

Question 2

How would the relationship between the following be described?

1. The number of alpha glucose 1-4 linkages in cellulose
2. The number of alpha glucose 1-4 linkages in starch

Answer 2

1 is less than 2

Question 3

What is the chemical mechanism by which cells make polymers from monomers?

Answer 3

Dehydration reactions

Question 4

Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified?

Answer 4

As a disaccharide

Question 5

Which of the following is true of cellulose?

a. it is a polymer composed of sucrose monomers
b. it is a storage polysaccharide for energy in plant cells
c. it is a major structural component of plant cell walls

Answer 5

it is a major component of plant cell walls

Question 6

Which of the following statements is false for the class of biological molecules known as lipids?

a. they are soluble in water
b. they are an important constituent of cell membranes
c. they contain more energy than proteins and carbohydrates
d. they are not true polymers
e. they sontian waxes and steroids

Answer 6

they are soluble in water

Question 7

What is a triacylglycerol?

Answer 7

A lipid made with three fatty acids and glycerol

Question 8

What is true about saturated fats?

Answer 8

A diet rich in these may contribute to atherosclerosis

Question 9

Large organic molecules are usually assembled by polymerization of a few kinds of simple subunits. Which of the following is an exception to this statement?

a. a steroid
b. cellulose
c. DNA
d. an enzyme
e. a contractile protein

Answer 9

a steroid

Question 10

Why are human sex hormones considered to be lipids?

Answer 10

They are steroids, which are nit soluble in water

Question 11

Which of the following is true regarding saturated fatty acids?

a. they are the predominant fatty acid in corn oil
b. they have double bonds between the carbon atoms of the fatty acids
c. they are the principal molecules in lard and butter
d. they are usually liquid at room temperature
e. they are usually produced by plants

Answer 11

They are the principal molecules in lard and butter

Question 12

All of the following contain amino acids except

a. hemoglobin
b. cholesterol
c. antibodies
d. enzymes
e. insulin

Answer 12

cholesterol

Question 13

What makes one amino acid different from another?

Answer 13

Different size chains (R groups) attached to an alpha (a) carbon

Question 14

The a helix and the B plated sheet are both common polypeptides forms found in which level of protein structure?

Answer 14

Secondary

Question 15

At which level of protein structure are disulfide bridges seen?

Answer 15

Tertiary

Question 16

What would be an unexpected consequence of chaining one amino acid in a protein consisting of 325 amino acids?

Answer 16

The primary structure would be changed, the tertiary structure of the protein might change, and the biological activity or function of the protein might be altered

Question 17

What is the term used for a change in a protein’s three-dimensional shape or conformation due to disruption of hydrogen binds, disulfide bridges, or ionic bonds?

Answer 17

Denaturation

Question 18

The volume encoded by the plasma membrane of plant cells is often much larger than corresponding volume in animal cells. The most reasonable explanation for this observation is that

Answer 18

plant cells contain a large vacuole that reduces the volume of the cytoplasm.

Question 19

Under what conditions would you expect to find a cell with a predominance of free ribosomes?

Answer 19

A cell that is producing cytoplasmic enzymes.

Question 20

In animal cells, hydrolytic enzymes are packaged to prevent general destruction of cellular components. Which organelle functions in this compartmentalization?

Answer 20

Lysosomes

Question 21

In the fractionation of homogenized cells using centrifugation, the primary factor that determines whether a specific cellular component ends up in the supernatant or the pellet is what?

Answer 21

The size and weight of the component

Question 22

The advantage of light microscopy over electron microscopy is that

Answer 22

light microscopy provides for higher resolving power than electron microscopy and light microscopy allows one to view dynamic processes in living cells

Question 23

Grana, thylakoids, and stoma are all components found in

Answer 23

chloroplasts

Question 24

Which of the following correctly lists the order in which cellular components will be found in the pellet when homogenized cells are treated with increasingly rapid spins in a centrifuge?

a. ribosomes, nucleus, mitochondria
b. chloroplasts, ribosomes, vacuoles
c. nucleus, ribosomes, chloroplasts
d. vacuoles, ribosomes, nucleus
e. nucleus, mitochondria, ribosomes

Answer 24

nucleus, mitochondria, ribosomes

Question 25

Which organelle in primarily involved in the synthesis of oils, phospholipids, and steroids?

Answer 25

Smooth endoplasmic reticulum

Question 26

Motor proteins provide for molecular motion in cells by interacting with what type of cellular structures?

Answer 26

Cytoskeletons

Question 27

A biologist is studying kidney tubules in small mammals. She wants to specifically examine the juxtaposition of different types of cells in these structures. The cells in question can be distinguished by external shape, size, and three dimensional characteristics. Which would be the optimum method for her study? a. transmission electron microscopy b. light microscopy using stains specific to kidney function c. light microscopy using living unstained material d. scanning electron microscopy

Answer 27

Scanning electron microscopy

Question 28

Which statement correctly characterizes bound ribosomes? a. bound ribosomes are enclosed in their own membrane b. bound are free ribosomes are structurally different c. bound ribosomes generally synthesize membrane proteins and secretory proteins d. the most common location for bound ribosomes is the cytoplasmic surface of the plasma membrane e. all of the above

Answer 28

bound ribosomes generally synthesize membrane proteins and secretory proteins

Question 29

Which structure is common to both plant and animal cells? a. cholorplasts b. cell wall c. Golgi apparatus d. centriole e. mitochondria

Answer 29

Golgi apparatus and mitochondria

Question 30

Which bonds can be broken, alpha or beta?

Answer 30

Alpha

Question 31

Secondary structure consists of what?

Answer 31

Coils and folds in the polypeptide chain, a helices and B plates sheets

Question 32

Tertiary

Answer 32

Held together by R group interactions, contains disulfide bridges

Question 33

Quaternary

Answer 33

All types of bonds involved, more than one polypeptide, a protein

Question 34

What are purines?

Answer 34

A type of nitrogenous base that has a six membered ring fused to a five membered ring (adenosine and guanine)