proteins

Question 1

what are proteins

Answer 1

large molecule of amino acids joined by peptide bonds folded into a specific 3 dimensional shape

Question 2

what is a codon

Answer 2

group of 3 base pairs

codes for specific amino acid

Question 3

What are amino acids

Answer 3

central carbon atom that is bonded to an amino group carboxyl group, a hydrogen atom, and a variable group (side chain) generally called an R group

Question 4

How many amino acids are there

How many can humans synthesize

Answer 4

20 in total

humans can synthesize 12

Question 5

Are amino acids polar or nonpolar

are they basic or acidic

Answer 5

Amino acids are amphiprotic-Having both acidic (hydroxyl) and basic (amino) functional groups.

Amino acids may be polar, non-polar, acidic, or basic depending on the nature of their side chains.

• Acidic amino acids have a carboxyl group as their R group.
• Basic amino acids have an amino group as their R group.

Question 6

How do amino acid polymers form proteins

Answer 6

Amino acid polymers twist and coil into a specific shape to form a protein.

Question 7

How in the conformation (final shape) of protein determined

Answer 7

The final shape is determined by the sequence of the amino acids and the interaction of their amino groups, carboxyl groups, or R groups.

Question 8

What is a polypeptide

Answer 8

an amino acid polymer

Question 9

What are the amino acids that humans cant synthesize

Answer 9

tryptophan, methionine, valine, threonine, phenylalanine, leucine, isoleucine, and lysine

Question 10

What are globular proteins

Answer 10

take on a spherical shape

Question 11

Proteins have 4 levels of structure. name them

Answer 11

primary, secondary, tertiary, quaternary

Question 12

What is a residue

Answer 12

each amino acid subunit in a polypeptide

Question 13

What happens if you change one amino acid in the primary structure
An example…

Answer 13

It will change the overall structure of the protein. It can alter or destroy the biological function of the protein
Sickle cell anemia

Question 14

What is the primary structure of proteins

Answer 14

The unique sequence of the polypeptide chain

Question 15

secondary is either an alpha helix or beta helix

a-helix

Answer 15

• spiral

- a hydrogen bond forms between the carboxyl group of one peptide bond and an amino group four bonds away

Question 16

secondary is either an alpha helix or beta helix

b-helix

Answer 16

-folded

polypeptide lie parallel to each other and hydrogen bonds form between carboxyl groups and amino groups on an adjacent

Question 17

In the tertiary structure what causes it to fold again

Answer 17

Forces of attraction between the polypeptide and its environment cause it to fold again

Question 18

amino acids with nonpolar r groups congregate where

Answer 18

on the interior of the structure

Question 19

amino acids with polar r groups congregate where

Answer 19

on the exterior of the structure

Question 20

what acid is the only amino acid where the R group is attached to the amino group

Answer 20

proline

Question 21

what happens when a sulfur-containing groups of cysteine residues come close to one another,

Answer 21

they can form a disulfide bridge (covalent bond) which is a strong stabilizer of tertiary structure.

Question 22

What is the quaternary structure

Example…

Answer 22

When polypeptide subunits come together to form a functional protein they are said to be in quaternary structure.

Hemoglobin is composed of four polypeptides, two identical α-chains and two identical β-chains.
Heme groups also present

Question 23

What is denaturation

Answer 23

The shape of a protein can change or even unravel if it is exposed to a change in temperature, pH, or ionic concentration.

Question 24

what happens If quaternary, tertiary, or secondary structures are denatured
Example…

Answer 24

a protein will usually return to its original shape when the denaturing factor is removed
(eg. curling/straightening hair).

Question 25

what happens if primary structures are denatured

Example…

Answer 25

the protein is destroyed

ex. cooking eggs