Proteins (2.4)

Question 1

How are peptide bonds formed?

Answer 1

A condensation reaction bonds the amine group of one aa to the carboxyl group of another aa. Water is removed and a peptide bond is formed.

Question 2

What are oligopeptides?

Answer 2

Oligopeptides are chains of less than 20 aa.

Question 3

How do different amino acids vary?

Answer 3

The R group in amino acids differ from each other. There are 20 different amino acids.

Question 4

What organelle links amino acids together to form polypeptides?

Answer 4

Ribosomes

Question 5

What is the formula for possible number of sequences for polypeptides?

Answer 5

20^n (n is the number of amino acids in the sequence. If n is 3, there are 20^3 possible sequences)

Question 6

How are polypeptides coded?

Answer 6

Polypeptides are coded by genes. Each amino acids needs three base genes (a 400 aa would need 12000 base genes).

Question 7

What are polypeptides?

Answer 7

Polypeptides are chains of amino acids joined by condensation reactions. They are the major component of proteins.

Question 8

How do condensation reactions work?

Answer 8

A condensation reactions combines the amine group (-NH2) from one amino acid and the carboxyl group (-COOH) of another amino acid. Water is removed. This forms a peptide bond.

Question 9

What are the four levels of structure in proteins?

Answer 9

Primary, secondary, tertiary, and quaternary.

Question 10

What is primary structure?

Answer 10

Primary structure is the amino acid sequence of the protein.

Question 11

What is secondary structure?

Answer 11

Secondary structure is the stretches or strands proteins or peptides, dependent on hydrogen bonding. Secondary structure includes alpha-helix and beta-sheet.

Question 12

What is the alpha-helix in secondary structure?

Answer 12

The alpha-helix is a right handed coiled strand.

Question 13

What is the beta-sheet in secondary structure?

Answer 13

The beta-sheet is a folded sheet.

Question 14

What is tertiary structure?

Answer 14

Tertiary structure is the overall three-dimensional shape of an entire protein molecule. The protein molecule will twist in whatever way encourages the most stability or lowest energy usage.

Question 15

What is quaternary structure?

Answer 15

Quaternary structure is the way proteins interact with each other to form a more complex protein molecule. Not all proteins have this structure.

Question 16

What are fibrous proteins?

Answer 16

Fibrous proteins provide structure, are insoluble in water, and are elongated with repeated structure. (Collagen, keratin, myosin, and actin)

Question 17

What are globular proteins?

Answer 17

Globular proteins include parts that are helical or sheet-like, soluble in water, have a hydrophobic r-group, and is stabilized between bonds in r-groups. (Hemoglobin, rubisco, and catalase).

Question 18

What is denaturation?

Answer 18

Denaturation is the change of structure in proteins due to an increase in heat or a change of pH.

Question 19

What are proteomes?

Answer 19

Proteomes are all of the proteins produced by a cell, tissue, or organism. They can be identified by gel electrophoresis.

Question 20

What is a genome?

Answer 20

A genome is all of the genes of a cell, tissue, or organism.