CH 5 HW

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

Amylose

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

An oxygen. The central carbon atom in an amino acid is bonded to an amino functional group, a carboxyl functional group, a side chain, and hydrogen.

Which part of an amino acid is always acidic?

Carboxyl functional group. The carboxyl 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.

The secondary structure of a protein results from _____.

Hydrogen bonds. Electronegative oxygen and nitrogen atoms leave hydrogen atoms with partial positive charges.

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

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

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

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

Which molecule is not a carbohydrate? Lipid Starch Cellulose Glycogen

Lipid

Nucleic acid polymers are made up of

Nucleotide monomers

Which monomers make up RNA?

Nucleotides

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

Peptide

Tertiary structure is NOT directly dependent on _____.

Peptide bonds. Peptide bonds link together the amino acids of a protein's primary structure.

Which polysaccharide contains a modified monosaccharide?

Peptidoglycan. The N-acetylglucosamine and N-acetylmuramic acid units that make up peptidoglycan are composed of modified glucose monomers.

Carbohydrate polymers are made up of

Simple sugar monomers

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

True

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

True. Enzymes in the digestive tract break down food molecules, which is a process that occurs by hydrolysis.

What is another name for a condensation reaction?

dehydration, refers to the removal of a water molecule during the linking of monomers.

Triglycerides vary with respect to the number of ...

hydrocarbon tails and C atoms in the tails.

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

hydrolysis. During 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.

A nucleotide is composed of a(n) _____.

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

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 double helix is 100 nucleotides long and contains 15 adenine bases, how many guanine bases does it contain?

35. Because of base pairing, if there are 15 adenine there must also be 15 thymine. This leaves 100-30 = 70 nucleotides to be divided evenly between guanine and cytosine.

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

made the fat less fluid.

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

rich in energy and insoluble in water.

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

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

Amino acid monomers

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

Cellulose: structural component of plant cell walls

The most unsaturated fats have ...

the most double bonds. Every double bond is a place where hydrogen could be added.