WEEK 5

Question 1

What is the monomer and polymer of a protein?

Answer 1

Monomer: Amino acid; Polymer: Polypeptide/protein

Question 2

What are the four parts of an amino acid?

Answer 2

Amino group, Carboxyl group, Central carbon, R-group (side chain)

Question 3

What does the R-group determine?

Answer 3

The properties and identity of the amino acid

Question 4

How many standard amino acids are there?

Answer 4

20

Question 5

What is a peptide?

Answer 5

A short chain of amino acids joined by a peptide bond

Question 6

How is a peptide formed?

Answer 6

By dehydration synthesis; forms a peptide bond

Question 7

What is a polypeptide?

Answer 7

A long chain of amino acids

Question 8

How is a polypeptide different from a protein?

Answer 8

A protein is a folded, functional polypeptide

Question 9

What is protein conformation?

Answer 9

The 3D shape of a protein

Question 10

Name the four levels of protein structure.

Answer 10

Primary, Secondary, Tertiary, Quaternary

Question 11

What is the primary structure of a protein?

Answer 11

The sequence of amino acids

Question 12

What is the secondary structure of a protein?

Answer 12

Alpha helices or beta-pleated sheets formed by hydrogen bonding

Question 13

What is the tertiary structure of a protein?

Answer 13

The overall 3D shape due to R-group interactions

Question 14

What interactions stabilize tertiary structure?

Answer 14

Hydrogen bonds, ionic bonds, disulfide bridges, hydrophobic interactions

Question 15

What is the quaternary structure of a protein?

Answer 15

The arrangement of multiple polypeptide subunits

Question 16

Do all proteins have quaternary structure?

Answer 16

No

Question 17

What is denaturation?

Answer 17

Loss of protein structure due to environmental changes

Question 18

How does denaturation affect a protein?

Answer 18

It loses its conformation and function

Question 19

What is renaturation?

Answer 19

Refolding of a denatured protein under the right conditions

Question 20

List 3 protein functions.

Answer 20

Enzymes, structure, transport

Question 21

Globular vs Fibrous protein?

Answer 21

Globular: spherical, soluble; Fibrous: long, insoluble

Question 22

What is an enzyme?

Answer 22

A protein that speeds up chemical reactions

Question 23

What is a substrate?

Answer 23

The molecule an enzyme acts on

Question 24

How are enzymes named?

Answer 24

Often based on substrate, ending in “-ase” (e.g., sucrase)

Question 25

How do enzymes speed up reactions?

Answer 25

By lowering activation energy

Question 26

Where does an enzyme bind a substrate?

Answer 26

The active site

Question 27

Can enzymes bind any substrate?

Answer 27

No, they are substrate-specific

Question 28

What is the enzyme-substrate complex?

Answer 28

A temporary complex formed during the reaction

Question 29

What is induced fit?

Answer 29

The enzyme slightly changes shape to fit the substrate

Question 30

Why must enzymes release products?

Answer 30

To repeat the reaction with new substrates

Question 31

How can environment affect enzyme activity?

Answer 31

pH, temperature, and salt levels can alter or denature enzymes

Question 32

What is a cofactor or coenzyme?

Answer 32

Non-protein helpers that assist enzymes

Question 33

What are the monomer and polymer of nucleic acids?

Answer 33

Monomer: Nucleotide; Polymer: Polynucleotide

Question 34

What are the three parts of a nucleotide?

Answer 34

Phosphate, 5-carbon sugar, nitrogenous base

Question 35

How are nucleotides joined?

Answer 35

By phosphodiester bonds

Question 36

What is DNA?

Answer 36

Deoxyribonucleic acid, stores genetic info

Question 37

Name the 4 nitrogenous bases in DNA.

Answer 37

Adenine, Thymine, Cytosine, Guanine

Question 38

Purines vs. Pyrimidines?

Answer 38

Purines (A, G) have 2 rings; Pyrimidines (C, T) have 1 ring

Question 39

How many DNA strands?

Answer 39

Two (double helix)

Question 40

What forms DNA’s backbone?

Answer 40

Sugar and phosphate

Question 41

What forms DNA’s rungs?

Answer 41

Paired nitrogenous bases (A–T, G–C)

Question 42

What does “complementary” DNA mean?

Answer 42

Each base has a specific pair (A–T, G–C)

Question 43

Why is DNA width uniform?

Answer 43

Purines pair with pyrimidines

Question 44

What does “antiparallel” mean in DNA?

Answer 44

Strands run in opposite directions

Question 45

DNA function?

Answer 45

Stores instructions to make proteins

Question 46

Why replicate DNA?

Answer 46

To pass genetic info to new cells

Question 47

What does DNA helicase do?

Answer 47

Unzips DNA at the replication fork

Question 48

What does DNA polymerase do?

Answer 48

Adds new nucleotides during replication

Question 49

What is produced by DNA replication?

Answer 49

Two identical DNA molecules

Question 50

What does "semiconservative" mean?

Answer 50

Each new DNA has one old and one new strand

Question 51

What is RNA?

Answer 51

Ribonucleic acid, single-stranded and used in protein synthesis

Question 52

Name the 4 RNA bases.

Answer 52

Adenine, Uracil, Cytosine, Guanine

Question 53

What base does uracil replace in RNA?

Answer 53

Thymine; Uracil is a pyrimidine

Question 54

4 Differences between DNA and RNA?

Answer 54

RNA: single-stranded, ribose sugar, uracil base, shorter-lived DNA: double-stranded, deoxyribose sugar, thymine base, long-lived

Question 55

What is ATP?

Answer 55

Adenosine triphosphate – energy molecule of the cell

Question 55

Structure of ATP?

Answer 55

Adenine + ribose + 3 phosphate groups

Question 56

ATP's role in the body?

Answer 56

Provides energy by losing a phosphate (forming ADP)

Question 57

What is ADP?

Answer 57

Adenosine diphosphate – can be recharged into ATP