Protein Structure and Characteristics Worksheet

The variations in the physical characteristics between different proteins are influenced by the overall amino acid compositions, but even more important is the unique amino acid

• number.

• sequence.

• bond.

• orientation.

Tags

NGSS.HS-LS1-1

Some proteins have alpha helices, some have beta sheets, and still others have a combination of both. What makes it possible for proteins to have these common structural elements?

• specific amino acid sequences

• side-chain interactions

• the hydrophobic-core interactions

• hydrogen bonds along the protein backbone

Which of the following is NOT a feature of α helices?

• anti-parallel

• 1 helical turn every 3.6 amino acids

• part of protein secondary structure

• amino acid side chains that point outward

Which of the following statements is TRUE?

• Disulfide bonds are formed by the cross-linking of methionine residues.

• Disulfide bonds are formed mainly in proteins that are retained within the cytosol.

• Disulfide bonds stabilize but do not change a protein’s final conformation.

• Disulfide bonds are more common for intracellular proteins, compared to extracellular proteins.

Chemical reactions carried out by living systems depend on the ability of some organisms to capture and use atoms from nonliving sources in the environment. The specific subset of these reactions that break down nutrients in food can be described as

• metabolic.

• catabolic.

• anabolic.

• biosynthetic.

Tags

NGSS.HS-LS1-7

NGSS.HS-LS2-3

The best way to know if an organic molecule has been reduced is to see if there was an increase in the number of _________ bonds.

• C-H

• C-O

• H-H

• C-N

Tags

NGSS.HS-LS1-6

ΔG° indicates the change in the standard free energy as a reactant is converted to product. Given what you know about these values, which reaction below is the most favorable?

• ADP + Pi → ATP ΔG° = +7.3 kcal/mole

• glucose 1-phosphate → glucose 6-phosphate ΔG° = -1.7 kcal/mole

• glucose + fructose → sucrose ΔG° = +5.5 kcal/mole

• glucose → CO2 + H2O ΔG° = -686 kcal/mole

ΔG measures the change of free energy in a system as it converts reactant (Y) into product (X). When [Y] = [X], ΔG is equal to

• ΔG° + RT.

• RT.

• ln [X]/[Y].

• ΔG°.

What does the K_m value indicate with respect to enzyme–substrate interactions?

• the maximum rate of catalysis

• the number of enzyme active sites

• the enzyme–substrate binding affinity

• the equilibrium rate of catalysis

Tags

NGSS.HS-PS1-2

The study of enzymes also includes an examination of how the activity is regulated. Molecules that can act as competitive inhibitors for a specific reaction are often similar in shape and size to the enzyme’s substrate. Which variable or variables used to describe enzyme activity will remain the same in the presence and absence of a competitive inhibitor?

• V_max

• V

• V_max and K_m

• K_m