Mastering Biology Chapter 5

How many molecules of water are used to completely hydrolyze a polymer that is 11 monomers long?

10

If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand?

3'-TAAACG-5'

If a DNA sample were composed of 10% thymine, what would be the percentage of guanine?

40

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 statements about the formation of polypeptides from amino acids is true? A bond can form between any carbon and nitrogen atom in the two amino acids being joined. The reaction occurs through the addition of a water molecule to the amino acids. Polypeptides form by condensation or hydrolysis reactions. A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid.

A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid.

Protein polymers are made up of ___ monomers.

Amino acid

Which complex carbohydrate contains only a-1,4-glycosidic linkages? Cellulose Amylose Glycogen Amylopectin

Amylose

Which of the following is not attached to the central carbon atom in an amino acid? A side chain ("R group") A carboxyl functional group An amino functional group An oxygen

An oxygen

A simple sugar is composed of equal parts carbon and water, which gave rise to the general name of any sugar as a ___ .

Carbohydrate

Which part of an amino acid is always acidic and why?

Carboxyl functional group, (COOH) contains two oxygen atoms that tend to pull electrons away from the hydrogen atom, so this group tends to lose a proton and is acidic.

Part complete Which of these is a polysaccharide? galactose cellulose lactose glucose sucrose

Cellulose

What does the term insoluble fiber refer to on food packages?

Cellulose

_____ is the most abundant organic compound on Earth.

Cellulose

Which of the following complex carbohydrates is listed with its correct function? Cellulose: structural component of plant cell walls Chitin: constituent of bacterial cell walls Starch: primary energy-storage molecule in animals Amylose: main component of plant starch

Cellulose: structural component of plant cell walls

The flow of genetic information in a cell goes from _____.

DNA to RNA to protein

Which of the following best summarizes the relationship between dehydration reactions and hydrolysis? Dehydration reactions assemble polymers; hydrolysis reactions break polymers apart. Dehydration reactions eliminate water from membranes; hydrolysis reactions add water to membranes. Dehydration reactions and hydrolysis reactions assemble polymers from monomers. Hydrolysis reactions create polymers and dehydration reactions create monomers.

Dehydration reactions assemble polymers; hydrolysis reactions break polymers apart

What is another name for a condensation reaction and what is the function?

Dehydration, it removes a water molecule during the linking of monomors.

Lactose, the sugar in milk, is a ___, because it can be split into two monosaccharides.

Disaccharide

What do fatty acid tails lack?

Double bond

The secondary structure of a protein results from _____.

Hydrogen bonds

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, a water molecule is used up in the breaking of a bond between two monomers. An H is added to one monomer, and an OH is added to the other.

Which molecule is NOT a carbohydrate and why? Starch Cellulose Glycogen Lipid

Lipid because it is a hydrophobic polymer.

Which of these classes of biological molecules does NOT include polymers? proteins nucleic acids carbohydrates lipids

Lipids

What do fats, steroids, and waxes have in common?

Low solubility in water.

A ___ cannot be hydrolyzed any further.

Monosaccharide

Which of the following statements about monosaccharide structure is true? All monosaccharides contain carbon, hydrogen, oxygen, and nitrogen atoms. A six-carbon sugar is called a pentose. Monosaccharides can be classified according to the spatial arrangement of their atoms. Aldoses and ketoses differ in the position of their hydroxyl groups.

Monosaccharides can be classified according to the spatial arrangement of their atoms.

Nucleic acid polymers are made up of ___ monomers.

Nucleotide

Nucleic acids are polymers made up of which of the following monomers? sugars nucleotides nitrogenous bases amino acids

Nucleotides

Which monomers make up RNA?

Nucleotides

Which of these is rich in unsaturated fats? a fat that is solid at room temperature olive oil lard butter beef fat

Olive oil

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

Peptide

Tertiary structure is NOT directly dependent on _____.

Peptide bonds

Which polysaccharide contains a modified monosaccharide? Starch Cellulose Peptidoglycan Glycogen

Peptidoglycan

A carbohydrate that yields many monosaccharides when hydrolyzed is a ___ .

Polysaccharide

___ structure is the sequence of amino acids in a protein.

Primary

Which polymers are composed of amino acids?

Proteins

___ structure is the result of two or more protein subunits assembling to form a larger, biologically active protein complex.

Quaternary

Which of these is NOT a lipid? RNA phospholipid cholesterol wax steroids

RNA

__ structure describes the alpha-helices and beta-sheets that are formed by hydrogen bonding between backbone atoms located near each other in the polypeptide chain.

Secondary

Carbohydrate polymers are made up of __ monomers.

Simple sugar

____ structure is achieved when a protein folds into a compact, three-dimensional shape stabilized by interactions between side-chain R groups of amino acids.

Tertiary

Which of the following statements about the 5' end of a polynucleotide strand of RNA is correct? The 5' end has a hydroxyl group attached to the number 5 carbon of ribose. The 5' end has a phosphate group attached to the number 5 carbon of ribose. The 5' end has phosphate attached to the number 5 carbon of the nitrogenous base. The 5' end has a carboxyl group attached to the number 5 carbon of ribose.

The 5' end has a phosphate group attached to the number 5 carbon of ribose.

Which feature of large biological molecules explains their great diversity?

The many ways that monomers of each class of biological molecule can be combined into polymers

What could happen if a mutation in a gene caused a hydrophobic amino acid in a polypeptide to be replaced by a hydrophilic amino acid?

The new amino acid would not form the same interactions with hydrophobic R groups, and the protein's shape would likely be affected.

How do phospholipids interact with water molecules?

The polar heads interact with water; the nonpolar tails do not.

Which of the following statements is an accurate description of proteins? The 20 amino acids found in proteins differ in the composition of their R groups, which may be either polar or charged. The primary structure of a protein is the order of amino acids in a polypeptide, as coded for in the DNA of a gene. Secondary structures, which include the alpha helix or beta pleated sheet, are held together by interactions between R groups. Tertiary structure is the overall shape of a polypeptide, which may be stabilized by hydrophobic interactions, hydrogen bonds, ionic bonds, and peptide bonds. Quaternary structure is only found in proteins that have four identical polypeptide subunits.

The primary structure of a protein is the order of amino acids in a polypeptide, as coded for in the DNA of a gene.

True or false? Enzymes in the digestive tract catalyze hydrolysis reactions.

True

True or false? Peptidoglycan is a polysaccharide found only in bacteria.

True

why is vegetable oil a liquid at room temperature while animal fats are solid?

Vegetable oil has more double bonds than animal fats.

Dr. Haxton told one of his students, "To move in the bloodstream, fats need the help of phospholipids." What would a good student say?

Yes. Nonpolar molecules aren't compatible with water. Water rejects nonpolar molecules such as fats, so fats travel inside particles that are coated with polar parts of phospholipids and proteins.

Which of the following descriptions best fits the class of molecules known as nucleotides? a nitrogenous base, a phosphate group, and a sugar a nitrogenous base and a sugar a nitrogenous base and a phosphate group a sugar and a purine or pyrimidine

a nitrogenous base, a phosphate group, and a sugar

What are the components of phospholipids?

a phosphate group, a glycerol, and fatty acids.

Which one of the following is NOT a component of each monomer used to make proteins? a carboxyl group, COOH a phosphorus atom, P an amino functional group, NH2 a side chain, R

a phosphorus atom, P

Glycogen is _____.

a polysaccharide found in animals

Proteins are polymers of _____.

amino acids

Steroids are considered to be lipids because they _____.

are not soluble in water

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

as a component of animal cell membranes

Which of the following includes all of the pyrimidines found in RNA and DNA? cytosine, uracil, and thymine cytosine and uracil cytosine, uracil, and guanine cytosine and thymine

cytosine, uracil, and thymine

Sucrose is formed when glucose is joined to fructose by a(n) _____.

glycosidic linkage

Which of the following statements is FALSE? Saturated fats _____. have many double bonds in the carbon chains of their fatty acids contain more hydrogen than unsaturated fats that consist of the same number of carbon atoms usually solidify at room temperature are more common in animals than in plants

have many double bonds in the carbon chains of their fatty acids

Humans can digest starch but not cellulose because _____.

humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but not the β-glycosidic linkages of cellulose

The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. Hydrogenated vegetable oil _____.

is solid at room temperature

glucose + glucose —> _____ by _____.

maltose + water ... dehydration synthesis

The characteristic that all lipids have in common is that _____.

none of them dissolves in water because they are nonpolar.

The building blocks or monomers of nucleic acid molecules are called _____.

nucleotides

A hydrophobic amino acid R group (side group) would be found where in a protein?

on the inside of the folded chain, away from water because they are nonpolar. They will avoid water contact.

A nucleotide is composed of a _____.

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

The four main categories of large biological molecules present in living systems are _____.

proteins, nucleic acids, carbohydrates, and lipids

Some regions of a polypeptide may coil or fold back on themselves. This is called _____, and the coils or folds are held in place by _____.

secondary structure ... hydrogen bonds

A dehydration reaction (or condensation reaction) is the process in which _____.

water molecules are produced as a polymer is formed from monomers