Proteins

Question 1

How many amino acids are needed to form a secondary structure protein?

Answer 1

Roughly 20

Question 2

Describe primary structure proteins

Answer 2

Unique linear sequences of amino acids. The sequence is dictated by DNA. They do not yet have a function

Question 3

How much DNA is in each cell?

Answer 3

About one metre

Question 4

What causes primary structure proteins to take on a secondary structure?

Answer 4

Hydrogen bonding between amino acids within the same polypeptide chain but some distance apart

Question 5

What are the two types of secondary structures in proteins?

Answer 5

A helixes and β-pleated sheets. Either could occur. They still have no function

Question 6

Describe the α helix structure of secondary structure proteins

Answer 6

Due to hydrogen bonds between the amide group of one residue and the carboxyl group of another residue not far away in the same polypeptide

Question 7

What shape do α helix secondary structure proteins take?

Answer 7

Spiral

Question 8

Describe β-pleated sheets

Answer 8

Due to hydrogen bonding between amide and carboxyl groups where the amino acid residues are on different polypeptides or on the same polypeptide where the chain has folded back on itself such that the two parts of the strand involved are lying side by side

Question 9

What shape does a β-pleated sheet secondary structure protein take on?

Answer 9

Paper folded in on itself

Question 10

What determines the function of a protein?

Answer 10

The shape of its amino acid configuration

Question 11

What are the types of amino acids?

Answer 11

20 total amino acids. 9 essential (must be supplemented by our diet) and 11 non-essential (created by the body)

Question 12

What bonds stabilize the structural development of secondary structure proteins?

Answer 12

Disulphide bridges

Question 13

Describe a tertiary structure of a protein

Answer 13

The three dimensional shape assumed by a polypeptide chain. It twists and folds on itself due to chemical interactions and has a small functional area called an active zone

Question 14

What chemical interactions determine the shape of tertiary structure proteins?

Answer 14

Ionic bonds, hydrogen bonds, disulphide bridges, hydrophobic interactions, and proline kinks

Question 15

How do amino acids form ionic bonds in tertiary structure proteins?

Answer 15

Positively charged radical groups attach to negatively charged R groups

Question 16

How do amino acids form hydrogen bonds in tertiary structure proteins?

Answer 16

Two polar radical groups attach

Question 17

How do amino acids form disulphide bridges in tertiary structure proteins?

Answer 17

Two cysteine amino acids form a covalent bond together on the same polypeptide chain

Question 18

What causes hydrophobic interactions in tertiary structure proteins?

Answer 18

Non-polar radical groups interacting and folding in water

Question 19

What determines the shape of a tertiary structure protein?

Answer 19

The chemical interactions which comprise it, such as ionic bonds, hydrogen bonds, disulphide bonds, and hydrophobic interactions

Question 20

What degree structure of a protein is the first functional protein?

Answer 20

Tertiary structure protein

Question 21

What are the functions of amino acids?

Answer 21

Break down food, grow and repair tissue, build muscle, provide energy source, create hormones

Question 22

Describe a quaternary structure protein

Answer 22

When a functional protein is composed of two or more polypeptides that fit together in a specific arrangement. They serve a more complex function. Examples include insulin, composed of two polypeptide chains and hemoglobin, composed of four

Question 23

Describe the denaturing of proteins

Answer 23

Gently heating, changing the pH, or certain chemical treatments can cause a protein to coagulate and lose its function. This is because a protein’s shape determines its function

Question 24

What is the basic structure of an amino acid?

Answer 24

Amino group — R group — carboxyl group

       H      H     O
       |       |      ǁ H+ — N — C — C — O-
       |       |
       H      R

Question 25

Draw an alanine molecule

Question 26

Draw a glycine molecule

Question 27

Draw a cysteine molecule

Question 28

Draw a proline molecule

Question 29

Draw a peptide bond reaction using the general structure of an amino acid

Question 30

What dictates the sequence of amino acids in a protein?

Answer 30

DNA

Question 31

How do proline kinks affect the tertiary structure of proteins?

Answer 31

Occurs in secondary structure proteins which affect tertiary structure. It disrupts hydrogen bonding to form α helixes and β-pleated sheets