chapter 3 bio practice questions

People with lactose intolerance do not have enough ______.

lactase

People who are lactose intolerant cannot extract energy from milk because

They are missing an enzyme

The element present in all organic molecules is

Carbon

Organic chemistry is currently defined as

the study of carbon compounds

The complexity and variety of organic molecules is due to

the chemical versatility of carbon atoms

Why is carbon so important in biology?

It can form a variety of carbon skeletons and host functional groups.

A single carbon atom can form a maximum of ________ covalent bond(s)

4

A carbon atom is most likely to form what kind of bond(s) with other atoms

covalent

The following molecule is best described as a(n) CH3-CH2-CH2-CH2

hydrocarbon

______ is a hydroxyl group.

OH-

Which best summarizes the relationship between dehydration reactions and hydrolysis?
A) Dehydration reactions create polymers; hydrolysis reactions break polymers apart.
B) Dehydration reactions require energy; hydrolysis reactions do not require energy.

Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers.

What name is given to the following reaction?
galactose + glucose ? lactose + water

dehydration reaction

In the following reaction, galactose is a ________.
galactose + glucose ? lactose + water

monomer

What name is given to the following reaction?
sucrose + water ? glucose + fructose

hydrolysis

Carbohydrates typically include ______.

C, H, and O atoms

Which of the following are isomers

glucose and fructose

Complete the equation:
monosaccharide + monosaccharide ? ________ + water

disaccharide

________ is the main carbohydrate found in plant sap

sucrose

In the following equation, lactose is a ______.
galactose + glucose ? lactose + water

disaccharide

Table sugar is ______.

sucrose, a monosaccharide

For good health, it is important to include ________ in our diets

polysaccharides

Maltose is a disaccharide composed of _________

two glucose molecules

Which of the following is an example of a polysaccharide

starch

Starch is made by _______

plants

What is the major structural difference between starch and glycogen?

the amount of branching that occurs in the molecules

most abundant organic compound on earth

cellulose

Animals store carbohydrates as

glycogen

Cellulose is an example of

fiber

________ is the naturally-occurring sugar found in milk.

lactose

Humans can digest starch but not cellulose because ________.

humans have enzymes that can hydrolyze the ? glycosidic linkages of starch but not the ? glycosidic linkages of cellulose.

Which of the following categories includes all others in the list?
A) disaccharide
B) polysaccharide
C) starch
D) carbohydrate

d

Which of the following is hydrophilic

cellulose

Sometimes when I have my morning coffee, which I drink black with no cream or sugar, I notice a thin film floating on top of the coffee. Since I have just read Chapter 3 of the text, I now realize the nature of this substance and so I run to my friend scr

hydrophobic substance

A glycerol with three fatty acids attached is referred to as a ________.

fat

What name is given to the following reaction?
glycerol + 3 fatty acids ? triglyceride + 3 water molecules

dehydration reaction

Saturated fats are saturated with ______.

Hydrogen

By definition, what type of fatty acid has double bonds

unsaturated

Which of the following is lowest in unsaturated fats

beef

Saturated fats

fats that are solid at room temperature

A fat that is hydrogenated is ______.

more solid

Which of the following is a health effect of a diet high in saturated fats

increased risk of heart attack

A friend of yours appears to have put on a lot of muscle very quickly. At the same time, you notice that your friend seems to have a lot of mood swings and appears depressed. It is reasonable for you to suspect that your friend has begun to take ________.

an anabolic steroid

Steroid hormones are derived from

cholesterol

______ is a steroid.

estrogen

Which statement about steroids is INCORRECT

they can be used therapeutically to treat diseases associated with muscle wasting

Enzymes are

proteins

Proteins are polymers constructed from ________ monomers

amino acid

Amino acids include a side chain as well as ________.

a central carbon, a hydrogen atom, an amino group, and a carboxyl group

Which two functional groups are always found in amino acids

Carboxyl and Amino

Amino acids are acids because they always possess ________ a functional group

carboxyl

There are ____ different amino acids

20

What is the name given to the reaction that breaks peptide bonds

hydrolysis

A protein's shape is determined primarily by its

amino acid sequence

A protein's function is most dependent on its

shape

Extremophilic bacteria are able to survive in hostile environments, including scalding hot water as well as springs and vents that reach temperatures over 100�C. Researchers studying these bacteria measured the function of a protein from an extremophile b

The bacterial protein functioned normally, whereas the human protein did not.

Nucleic acids are polymers of ________ monomers

nucleotide

A nucleotide is composed of a(n) _____.

a sugar, a phosphate group, and a nitrogen-containing base

A specific stretch of DNA that programs the amino acid sequence of a polypeptide is a

gene

One of the primary functions of RNA molecules is to

function in the synthesis of proteins

The relation between amino acid and polypeptide is similar to the relation between ________

nucleotide and nucleic acid

DNA nucleotides include

thymine, guanine, adenine, and cytosine

Which of the following is TRUE with regard to a DNA molecule?

The amount of adenine is equal to the amount of thymine, and the amount of guanine is equal to the amount of cytosine

If one strand of a DNA double helix has the sequence AGTACTG, what will be the sequence of the other strand?

TCATGAC

When nucleotides polymerize to form a nucleic acid, ________.

a covalent bond forms between the sugar of one nucleotide and the phosphate of a second

How does RNA differ from DNA?

RNA contains uracil; DNA contains thymine

A DNA molecule has the sequence AGTTCAACT. The equivalent RNA molecule would have the sequence ________.

AGUUCAACU

The two strands of a DNA double helix are held together by

hydrogen bonds

The ability to tolerate lactose throughout life most likely arose in

cultures that keep dairy herds