Polymerization is a process that:
a. crates bonds between amino acids in the formation of a peptide chain.
b. often involves the removal of a water molecule.
c. like the sugar of one nucleotide with the phosphate of the next.
d. requires a condensation or dehydration reaction.
e. may involve all of the above
Which of the following is NOT true of a pentose?
a.It can be found in nucleic acids
b. It can occur in a ring structure.
c. It has the formula C5H12O5
d. It has one carbonyl and four hydroxyl groups.
e. it may be an aldos or a ketose
Disaccharides can differ from each other in all of the following ways except:
a. In the number of their monosaccharides
b. as enantiomers
c. In the monomers involved
d. In the location of their glycosidic linkage.
e. In their structural formulas
Which of the following is not true of cellulose?
A. It is the most abundant organic compound on Earth.
b. it differs from starch because of the configuration of glucose and the geometry of the glycosidic linkage.
c. It may be hydrogen-bonded to neighboring cellulose molecules to form microfibrils.
d. Few organisms have enzymes that hydrolyze this glycosidic linkages.
e.Its monomers are glucose with nitrogen containing appendages
Plants store most of their energy for later use as:
a. unsaturated fats
b. saturated fats
What happens when a protein denatures?
a. Its primary structure is disrupted.
b. Its secondary and tertiary structures are disrupted.
c. It becomes irreversibly insoluble and precipitates.
d. It hydrolyzes into component amino acids.
e. Its hydrogen bonds, ionic bonds, hydrophobic interactions, disulfide bridges, and peptide bonds are disrupted.
The "a" helix of proteins is..?
a. Part of the tertiary structure and is stabilized by disulfide bridges.
b. a double helix.
c. stabilized by hydrogen bonds and commonly found in fibrous proteins.
d. found in some regions of globular proteins and stabilized by hydrophobic interactions.
e. a complementary sequence to messenger RNA.
A fatty acid that has the formula C16H32O2 is:
e. part of a steroid molecule
Three molecules of the fatty acid in question 8 are joined to a molecule of glycerol (C3H8O3). The resulting molecule has the formula:
e . C51H98O6
"B" pleated sheets are characterized by:
a. disulfide bridges between cysteine amino acids.
b. parallel regions of the polypeptide chain held together by hydrophobic interactions.
c. folds stabilized by hydrogen bonds between segments of the polypeptide backbone.
d. membrane sheets composed of phospholipids.
e.hydrogen bonds between adjacent cellulose molecules.
Cows can derive nutrients from cellulose because:
a. They can produce the enzymes that break the "B" linkages between glucose molecules.
b. THey chew and rechew their cud so that cellulose fibers are finally broken down.
c.Its rumin contains prokaryotes that can hydrolyze the bonds of cellulose.
d. Their intestinal tract contains termites, which harbor microbes that hydrolyze the bonds of cellulose.
e. They can convert cellulose to starch and then hydrolyze starch to glucose
Which of these molecules would provide the most energy (kcal/g) eaten?
What determines the sequence of the amino acids in a particular protein?
a. its primary structure
b. the sequence of nucleotides in RNA, which was determined by the sequence of nucleotides in the gene for that protein
c. the sequence of nucleotides in DNA, which was determined by the sequence of nucleotides in RNA.
d. the sequence of RNA nucleotides making up the ribosome
e. the three-dimensional shape of the protein
Sucrose is made from joining a glucose and a fructose molecule in a dehydration reaction. What is the molecular formula for this disaccharide?
How are the nucleotide monomers connected to form a polynucleotide?
a. hydrogen bonds between complementary nitrogenous base pairs.
b. ionic attractions between phosphate groups
c. disulfide bridges between cysteine amino acids.
d. covalent bonds between the sugar of one nucleotide and the phosphate of the next
e. ester linkages between the carboxyl group of one nucleotide and the hydroxyl group on the ribose of the next
Which of the following would be the most hydrophobic molecule?
c. Amino Acid
If the nucleotide sequence of one strand of DNA is helix is 5'GCCTAA3', what would be the 3'-5' sequence on the complementary strand?
Monkeys and humans share many of the same DNA sequences and have similar proteins, indicating that:
a. the two groups belong to the same species.
b. the two groups share a relatively recent common ancestor.
c. humans evolved from monkeys
d. monkeys evolved from humans
e. the two groups first appeared on Earth at about the same time.
Which of the following would be a major component of cell membrane of a fungus?
E. Unsaturated fatty acids
Hydrophobic as well as hydrophilic interactions would be important for which of the following types of molecules?
B. Unsaturated fats
C. Glycogen and cellulose
E. All of the above
What are trans fats?
a. hydrogenated vegetable oils that have been identified with health risks
b. fats made from cholesterol that are components of plaques in the walls of blood vessels.
c. fats that are derived from animal sources and are associated with cardiovascular disease
d. fats that contain trans double bonds and may contribute to atherosclerosis
e. polyunsaturated fats produced by removing H from fatty acids and forming cis double bonds
Which of the following is not one of the many functions performed by proteins?
A. signals and receptions
B. enzymatic catalyst for metabolic reactions
C. protection against disease
D. contractile components of muscle.
E. transport of proteins by chaperonins