BIOLOGY CHAPTER 3 ( Mastering)

proteins can be made from varying combinations of ___________amino acids.

20

Polymers that contain sugars ... (a) may store hereditary information. (b) may store energy. (c) may protect cells. Both (b) and (c). (a), (b), and (c).

A. may store hereditary information. B. may store energy. C. may protect cells

Which of the following lists contains only polysaccharides? A. fructose, cellulose, and glucose B. starch, amino acids, and glycogen C. cellulose, starch, and glycogen D. sucrose, starch, and cellulose

C. cellulose, starch, and glycogen

Which of these is NOT a lipid? A. wax B. steroids C. phospholipid D. cholesterol E. RNA

E. RNA

What feature of fats makes them hydrophobic?

Fats have nonpolar hydrocarbon chains.

Lipids are diverse compounds that are grouped together because they are______.

Hydrophobic

Which of these does NOT contain a structural protein? A. ovalbumin B. ligaments C. spider silk D. tendons E. muscles

Ovalbumin

A gene provides the directions to build a molecule of _________ ; the genetic instructions it carries are then translated into the amino acid sequence of a protein.

RNA (ribonucleic acid)

What do DNA, proteins, and fats have in common?

They all contain carbonyl groups

__________ have one or more double bonds in their hydrocarbon chains and are usually found in vegetable oils.

Unsaturated fats

A glucose molecule is to starch as __________ A. a steroid is to a lipid B. a protein is to an amino acid C. a nucleic acid is to a polypeptide D. a nucleotide is to a nucleic acid

a nucleotide is to a nucleic acid

Glycogen

a polysaccharide found in animals

A(n) __________ is a building block of polypeptides, such as the protein hemoglobin.

amino acid

Glucose molecules are to starch as ________ are to proteins.

amino acids

Insulin is a protein hormone that regulates blood glucose levels and is a polymer of_________ .

amino acids

Proteins are polymers of _____.

amino acids

A function of cholesterol that does not harm health is its role _____.

as a component of animal cell membranes

Triglycerides vary with respect to the number of ...

atoms in the tails & double bonds in the tails.

A fatty acid consists of a ________ and a long hydrocarbon chain.

carboxyl group

An amino acid is so named because its central carbon is linked to both an amino group and a __________.

carboxyl group

_____ is the most abundant organic compound on Earth.

cellulose

DNA differs from RNA because DNA

contains thymine in place of uracil

The reaction that joins two monomers to form a polymer is known as a _____ reaction. The molecule of water formed is due to the interaction between _____ and a hydrogen ion.

dehydration ... a hydroxyl group

What is another name for a condensation reaction?

dehydration synthesis

A DNA nucleotide is composed of a __________.

deoxyribose sugar, which is bonded to a phosphate group and a nitrogenous base

A fat molecule is composed of two types of smaller molecules:_______ and fatty acids.

glycerol

In fat synthesis,________and fatty acids combine to make fats plus________.

glycerol; water

Animals store energy in the form of _________, a carbohydrate made up of thousands of ________.

glycogen; monosaccharides

The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases.

hydrogen bonds

What is the name of the process during which a bond between two monomers is broken?

hydrolysis

In the reaction that builds a fat,________ groups react with ________ groups.

hydroxyl; carboxyl

Dehydration reactions __________. They do so by __________.

link monomers to form a polymer; removing a water molecule

A food company hydrogenated a barrel of fat. The treatment ...

made the fat less fluid.

glucose + glucose —> _____ by _____

maltose + water ... dehydration synthesis

Which of these is a source of lactose? A. sugar beets B. potatoes C. sugar cane D. starch E. milk

milk

Nucleic acid polymers are made up of _________monomers.

necleotide

A(n) __________ is a building block of polynucleotides such as DNA.

nucleotide

What type of bond joins the monomers in a protein's primary structure?

peptide

Tertiary structure is NOT directly dependent on _____.

peptide bonds

The most unsaturated fats have .

the most double bonds.

What is the general function of enzymes within a cell?

to speed up chemical reactions

A disaccharide forms when

two monosaccharides join by dehydration synthesis

Fatty acids with double bonds between some of their carbons are said to be

unsaturated

If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain?

75

Which of the following is an example of a dehydration reaction? A. DNA molecules are replicated in a cell by building new DNA molecules from nucleotides. B. Amylose, a polysaccharide, is broken down by amylase, an enzyme found in your saliva. C. A group of enzymes "cut" a mutated protein into smaller molecules, preventing it from harming the cell. D. Casein, a type of protein found in milk, is broken down into amino acids by enzymes in the digestive tract.

A. DNA molecules are replicated in a cell by building new DNA molecules from nucleotides.

Once you eat a cookie, enzymes in your digestive tract begin to break down the cookie into smaller molecules. Which two statements are true regarding this process? A. Hydrolysis reactions are breaking the macromolecules in the cookie down into smaller molecules. B. Dehydration reactions are breaking the macromolecules in the cookie down into smaller molecules. C. Water is released during the reactions that break the macromolecules in the cookie down into smaller molecules. D. Water is required for the reactions that break the macromolecules in the cookie down into smaller molecules.

A. Hydrolysis reactions are breaking the macromolecules in the cookie down into smaller molecules. D. Water is required for the reactions that break the macromolecules in the cookie down into smaller molecules.

Which of these is rich in unsaturated fats? A. a fat that is solid at room temperature B. olive oil C. lard D. beef fat E. butter

B. Olive oil

Of the following sugar molecules, which is not a disaccharide?

B. fructose Explanation: Fructose is a monosaccharide

What do phospholipids and cholesterol have in common?

Both are important components of cell membranes.

When two monosaccharides link to form a disaccharide, the by-product is __________.

C. water Explanation: Two monosaccharides are linked via a dehydration reaction, and water is produced in the process.

Which of these is a polysaccharide? A. lactose B. sucrose C. galactose D. cellulose E. glucose

D. cellulose

Which of the following organisms contain the polysaccharide chitin? A. animals and plants B. plants and bacteria C. insects and plants D. fungi and insects

D. fungi and insects

Which is the correct term for compounds that do not mix with water? A.hydrophilic B. protein C. phospholipids D. hydrophobic

D. hydrophobic

___________ provides directions for its own replication. It also directs cell activities by providing instructions for building proteins.

DNA (deoxyribonucleic acid)

Myoglobin is a protein that binds oxygen molecules and is a polymer of ___________.

amino acids

Protein polymers are made up of _________monomers.

amino acids

Which of the following would be correctly classified as a protein? A. an enzyme B. cholesterol C. cellulose D. starch

an enzyme

The storage form of carbohydrates is ________ in animals and ________ in plants.

glycogen; starch

The secondary structure of a protein results from _____.

hydrogen bonds

Defensive proteins are manufactured by the _____ system.

immune

A(n) ___________ is a building block of polysaccharides such as starch.

monosaccharide

Cellulose differs from starch in that

most animals cannot break down cellulose, whereas starch is easily digested.

The monomers of nucleic acids consist of a phosphate group, a five-carbon sugar, and a ____________

nitrogenous base

DNA is composed of building blocks called _____.

nucleotides

The nucleic acids DNA and RNA carry genetic information and are made up of many ___________.

nucleotides

A phospholipid is composed of

one glycerol molecule linked to one phosphate group and two fatty acids

A nucleotide is composed of a(n) _____.

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

The lipids that form the main structural component of cell membranes are _____.

phospholipids

_________are a major component of cell membranes. They form a bilayer with their hydrophobic tails mingling together and their hydrophilic heads facing the watery environment on both sides of the membrane.

phospholipids

Cellulose is a _____ made of many _____.

polymer ... glucose molecules

A(n) ________ is a polymer of nucleotides.

polynucleotide

A(n) _________ is a polymer of amino acids.

polypeptide

A(n) _________ is a polymer of monosaccharides.

polysaccharide

The presence of many C-C and C-H bonds causes fats to be ...

rich in energy and insoluble in water.

The hydrocarbon chains of _________ are not kinked, and thus pack closely together, making animal fats solid at room temperature.

saturated fatty acids

Carbohydrate polymers are made up of ______ monomers.

simple sugar

__________are lipids with a structure consisting of four fused rings. Many sex hormones are made from this type of lipid.

steriods

What components make up a nucleotide?

sugar, nitrogenous base, phosphate group