Exam 3: Proteins, Carbohydrates, and Lipids

A research lab working on a protein exchanges a methionine with an isoleucine in one experiment and exchanges the same methionine with a glutamic acid in a second experiment.Discuss how these changes could result in very different changes to the protein's tertiary structure and why.

Refer to the figure below. How many and what type(s) of atoms will occupy positions in the ring that forms when this molecule cyclizes?

All amino acids have an optical isomer except

A question was raised during a class discussion about whether it was possible for two isomers to have different biological properties.A student from the class responded, stating that only optical isomers met this requirement.Which statement provides the best evaluation of this student's assertion?

After discovering a marine plant that humans had never seen before, a biologist took small samples of the organism's stem and roots for chemical analysis.How many classes of biological macromolecules should encompass the range of different macromolecules that the biologist will find in the analysis, and what are these classes?

Refer to the figure of a hemoglobin protein below. If a hemoglobin exposed to high temperatures is returned to normal temperature in the presence of chaperone proteins, it will refold _______ and _______ function.

Starch and glycogen, which are both polysaccharides, differ in their functions in that starch is _______, whereas glycogen _______.

The reaction H-A-OH + H-B-OH  H-A-B-OH + H₂O represents a(n) _______ reaction.

Refer to the figures below. Of the sugars shown, which are hexose sugars and which are pentose sugars?

A  pleated sheet organization in a polypeptide chain is an example of _______ structure.

Refer to the figures below, showing two pairs of isomers. Pair 1 would be classified as cis-trans isomers, while pair 2 would be classified as _______ isomers.

All lipids are

Protein function

An essential functional group involved in cellular energy reactions is the _______ group.

In some cases, a single amino acid substitution can cause a protein to lose its biological activity.In other cases, a single amino acid substitution causes no change to a protein's biological activity.Which statement can best be used as evidence to support an explanation for these observations?

A carbohydrate with 12 oxygen molecules would have _______ hydrogen molecules.

Cis and trans isomers

If an amino acid involved in the ability of an enzyme to bind a substrate were changed from a tyrosine to a phenylalanine, what would happen to the enzyme?

A hydrolysis reaction requires

Refer to the figures below. A student claims that adding functional groups onto carbohydrates does not provide any biological advantage.Which statement best evaluates this claim, using cellulose and chitin as evidence for the student's argument?