Mastering Biology: Chapters 2-5

What are three ways monosaccharides differ from one another?

(1) the location of their carbonyl group; (2) the number of carbon atoms they contain; and (3) the orientations of their hydroxyl groups.

Which of the following helps most to explain why water has a high specific heat?

A water molecule can make 4 hydrogen bonds.

Though you add heat, the temperature of boiling water remains constant because ...

it takes energy to break hydrogen bonds.

What type of information is used to direct different polypeptides to fold into different shapes? 1) the temperature of denaturation of the polypeptide 2) the molecular mass of the polypeptide 3) order of amino acids that make up the polypeptide 4) type of amino acids that make up the polypeptide

3 and 4

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 one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence _____.

5'TGCAAT3'

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) A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid. b) A bond can form between any carbon and nitrogen atom in the two amino acids being joined. c) The reaction occurs through the addition of a water molecule to the amino acids. d) Polypeptides form by condensation or hydrolysis reactions.

A

Which of the functional groups behaves as a base?

A

Which one of these is an amino group?

A

Which of the following statements about protein primary structure is true?

Primary structure is produced by the unique sequence of amino acids in a protein.

There have been homicide cases where dried blood from a jacket was used ten years after the homicide to convict the killer. Why was the blood still a good source of DNA?

The DNA in the blood was incredibly stable due to the strength of the bonds in DNA structure.

When you eat gluten, enzymes present in your stomach and intestines digest all but a few short peptides. How do enzymes accomplish this activity?

The active site of an enzyme binds to a gluten protein and facilitates the hydrolysis reaction that breaks apart peptide bonds.

Adhesion

The clinging of one substance to another (water climbing up the roots of a tree to its leaves)

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?

peptidoglycan

A nucleotide is composed of a(n) _____.

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

Some viruses consist only of a protein coat surrounding a nucleic acid core. If you wanted to radioactively label the nucleic acids separately from the protein, you would use radioactive _____.

phosphorus

The typical college student diet is rich in gluten-containing foods. Make a list of six items that you would not be able to eat if you were diagnosed with celiac disease.

pizza, soy sauce, bagels, burritos, pasta, batter fried chicken

The unequal sharing of electrons within a water molecule makes the water molecule _____.

polar

In this molecule, what type of bond is found between the oxygen and hydrogens?

polar covalent

Which statement is true of water's tensile strength? (a) It results from hydrogen bonding. (b) It helps to pull water through plants. (c) It involves both cohesion and adhesion. (d) Both (a) and (b). (e) (a), (b), and (c).

A, B and C

Which of these illustrates the secondary structure of a protein?

Alpha helices and beta pleated sheets are characteristic of a protein's secondary structure.

If you hold a salty cracker in your mouth long enough, it will begin to taste sweet. What is responsible for this change in taste?

Amylase breaks down the starch in the cracker into glucose monomers, which stimulate the sweet receptors in your tongue.

Which complex carbohydrate contains only a-1,4-glycosidic linkages?

Amylose

Which of these groups plays a major role in energy transfer?

B

Which of these is a phosphate group?

B

Water is a source of ______________ for chemical reactions in cells. (a) hydrogen atoms (b) oxygen atoms (c) energy (d) Both (a) and (b) (e) (a), (b), and (c).

Both A and B

Which factor is important in making it possible to cool yourself by sweating? Think carefully! a) Molecules collide with varied angles and speeds. (b) Hydrogen bonds are relatively weak. (c) Water has more energy at the body surface. (d) Both (a) and (b). (e) (a), (b), and (c).

Both A and B

Which statement helps to explain why ice is less dense than liquid water? (a) Water molecules make hydrogen bonds at definite angles. (b) Cold molecules move less than warm molecules. (c) Hydrogen bonds lengthen in the cold. (d) All of the above. (e) Both (a) and (b).

Both A and B

Which of these is a carbonyl group?

C

The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions?

C18H32O16

Which part of an amino acid is always acidic?

Carboxyl functional group

_____ is the most abundant organic compound on Earth.

Cellulose

What is the four emergent properties of water?

Cohesion and Adhesion, Expansion upon freezing, Moderation of Temperature, Versatility as a Solvent

You have just sequenced a new protein found in mice and observe that sulfur-containing cysteine residues occur at regular intervals. What is the significance of this finding?

Cysteine residues are involved in disulfide bridges that help form tertiary structure.

Which of these functional groups is characteristic of alcohol?

D

Which of these is a hydroxyl group?

D

Which of the following is the strongest evidence that protein structure and function are correlated?

Denatured (unfolded) proteins do not function normally.

Which of these is a carboxyl group?

F

A water molecule can bond to up to _____ other water molecules by ____ bonds

Four, hydrogen

Which of the following takes place as an ice cube cools a drink?

Kinetic energy in the liquid water decreases.

Which of the following statements about monosaccharide structure is true?

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

Which statement must be mentioned in explaining why amphipathic molecules line up at a water surface?

Polar groups attract one another

Why doesn't oil mix with water? (a) Nonpolar molecules repel water molecules. (b) Polar molecules repel nonpolar molecules. (c) Polar molecules attract one another. (d) Nonpolar molecules attract one another. (e) Both (a) and (d).

Polar molecules attract one another

Why are hydrocarbons insoluble in water?

The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.

How are the structures of RNA and DNA similar?

Their sugar-phosphate backbones are formed by phosphodiester linkages.

what describes how the carbohydrates you ate during breakfast today are functioning in your body right now?

They are storing chemical energy, indicating cell identity, and serving as raw material for synthesizing other molecules.

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

True

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

True

Cohesion

Water molecules sticking to each other.

Dissolving is best described as

a mingling of molecules and/or ions.

Glycogen is _____.

a polysaccharide found in animals

Protein polymers are made up of ______ monomers.

amino acid

Proteins are polymers of _____.

amino acids

Which of the following is not attached to the central carbon atom in an amino acid?

an oxygen

The open spaces in water's crystal structure make it possible for ... (a) aquatic life to exist at the North Pole. (b) water to have a low boiling point. (c) life to occur in hot springs. (d) Both (b) and (c). (e) (a), (b), and (c)

aquatic life to exist at the North Pole

Which of these is a polysaccharide?

cellulose

Which of the following complex carbohydrates is listed with its correct function?

cellulose: structural component of plant cell walls

What is another name for a condensation reaction?

dehydration

Identify three possible components of a DNA nucleotide.

deoxyribose, phosphate group, thymine

The tendency of an atom to pull electrons toward itself is referred to as its _____.

electronegativity

Which of these bonds is weakest?

hydrogen 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 type of bond is directly involved in the formation of an αα-helix?

hydrogen bonds between amino acid residues

Water has surface tension because ...

hydrogen bonds between surface water molecules resist being stretched.

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

hydrolysis

Which molecule is not a carbohydrate?

lipid

Which of these is a source of lactose?

milk

Nucleic acid polymers are made up of ______ monomers.

nucleotide

Which monomers make up RNA?

nucleotides

When polymerization of a protein is complete, but a protein is still completely linear, what is the highest level of structure in the protein?

primary

You disrupt all hydrogen bonds in a protein. What level of structure will be preserved?

primary structure

Which polymers are composed of amino acids?

proteins

Carbohydrate polymers are made up of ______ monomers.

simple sugars

To act as an effective coolant in a car's radiator, a substance has to have the capacity to absorb a great deal of heat. You have a reference book with tables listing the physical properties of many liquids. In choosing a coolant for your car, which table would you check first?

specific heat

Why isn't this insect drowning?

surface tension