What are two types of secondary protein structure?

What does secondary protein structure refer to? What kinds of interactions maintain secondary protein structure?

Describe the different types of plant cells in plant tissues.

Explain why each of the following pairs are complementary proteins:

a. beans and oats

Peptides from sweet potato with antioxidant properties have the following sequence of amino acids. Draw the structure for given peptide and write the one-letter abbreviations.
a. Asp–Cys–Gly–Tyr
b. Asn–Tyr–Asp–Glu–Tyr

Draw the structure for each of the following peptides, and give the three-letter and one-letter abbreviations for their names:

d. histidylglycylglutamylisoleucine

Draw the structure for each of the following peptides, and give the three-letter and one-letter abbreviations for their names:

c. methionylglutaminyllysine

Draw the structure for each of the following peptides, and give the three-letter and one-letter abbreviations for their names:

a. prolylaspartate

Draw the structure for each of the following peptides, and give the three-letter and one-letter abbreviations for their names:

b. serylphenylalanine

Draw the structure for each of the following peptides, and give the three-letter and one-letter abbreviations for their names:

b. threonylleucine

The speed of DNA replication at a replication fork is about 100 nucleotides per second in human cells. What is the minimum number of origins of replication that a human cell must have if it is to replicate its DNA once every 24 hours? Recall that a human cell contains two copies of the human genome—one inherited from the mother, the other from the father—each consisting of 3 $\times$ 109 nucleotide pairs.

Do you think Montresor achieves the kind of revenge he says? Defend your answer.

In "The Cask of Amontillado," what happens to Fortunato?

In "The Cask of Amontillado," why does Montresor, the narrator, want revenge?