3.3 Amino Acids, Proteins, and DNA

Question 1

What is a dipeptide?

Answer 1

A dipeptide is formed from two amino acids joined by a peptide bond.

Question 2

What is a tripeptide?

Answer 2

A tripeptide is formed when a dipeptide reacts with another amino acid.

Question 3

What is the primary structure of a protein?

Answer 3

The specific sequence of amino acids held together by peptide bonds.

Question 4

What type of bond holds the secondary structure of proteins?

Answer 4

Hydrogen bonds.

Question 5

What attractions contribute to tertiary protein structure?

Answer 5

Tertiary structure is held by:
* Disulfide bridges
* Ionic attractions
* Hydrogen bonds.

Question 6

What is a zwitterion?

Answer 6

A zwitterion is a molecule that has both positive and negative charges but is overall neutral.

Question 7

What is the by-product of a condensation reaction when forming a peptide?

Answer 7

Water (H2O).

Question 8

What is the strongest bond that can be found within a protein’s tertiary structure?

Answer 8

Disulfide bridges.

Question 9

True or False: Only L-alanine occurs naturally.

Answer 9

True.

Question 10

What is the active site of an enzyme?

Answer 10

The unique shape region of an enzyme where substrate molecules bind.

Question 11

What is the lock and key hypothesis?

Answer 11

The model describing how specific substrates fit into the active site of enzymes.

Question 12

Fill in the blank: Enzymes are typically ______ proteins.

Answer 12

globular.

Question 13

What happens to an enzyme’s active site when temperature increases?

Answer 13

The active site shape can change, preventing substrate binding.

Question 14

What are the complementary base pairs in DNA?

Answer 14

Adenine (A) pairs with Thymine (T) and Guanine (G) pairs with Cytosine (C).

Question 15

How many hydrogen bonds are formed between A and T?

Answer 15

2 hydrogen bonds.

Question 16

How many hydrogen bonds are formed between G and C?

Answer 16

3 hydrogen bonds.

Question 17

What is the structure of cisplatin?

Answer 17

Cisplatin has a central platinum atom bonded to two chloride ligands and two ammonia ligands.

Question 18

What is the main action of cisplatin in cancer treatment?

Answer 18

Cisplatin binds to guanine bases in DNA, preventing replication.

Question 19

What are the adverse effects of cisplatin?

Answer 19

Cisplatin can cause hair loss and affect healthy cells, leading to side effects.

Question 20

Fill in the blank: The sugar found within DNA is a ______ sugar.

Answer 20

pentose.

Question 21

What is the function of superoxide dismutase?

Answer 21

To catalyze the dismutation of superoxide into oxygen and hydrogen peroxide.

Question 22

What is the role of nitrogenase?

Answer 22

To catalyze the conversion of atmospheric nitrogen into ammonia.

Question 23

What is the significance of the amino acid serine in biochemical reactions?

Answer 23

Serine can react with acids and bases and can form a zwitterion.

Question 24

What is the term for molecules that inhibit enzyme activity?

Answer 24

Enzyme inhibitors.

Question 25

What is the role of computational chemistry in drug development?

Answer 25

To simulate interactions of enzymes and drug candidates using mathematics and algorithms.

Question 26

What is the nature of attractions that can form between an inhibitor and an enzyme?

Answer 26

Ionic and hydrogen bonds, among others.

Question 27

How does pH affect enzyme function?

Answer 27

Altering pH changes the charges of groups within the enzyme, affecting bonding and active site shape.

Question 28

How are nucleotides formed?

Answer 28

From a phosphate, 2-deoxyribose, and a base.

Question 29

What is the shape and bond angle in cisplatin?

Answer 29

Cisplatin has a square planar shape.

Question 30

What are the four different bases that could be attached to a nucleotide?

Answer 30

Adenine (A), Cytosine (C), Guanine (G), Thymine (T).