amino acid facts

Question 1

2 functional groups in all amino acids

Answer 1

amino group and carboxylate group

Question 2

what differentiates each amino acid from one another

Answer 2

its side chain / R group

Question 3

removal of H2O from linking amino acids

Answer 3

condensation

Question 4

regenerates the original carboxylic acid and amino groups when breaking peptide bonds between amino acids

Answer 4

hydrolysis

Question 5

point of weakness in peptides

Answer 5

C=O group of the amide

Question 6

amino terminal end

Answer 6

end of the peptide that has the H3N+ group

Question 7

carboxyl-terminal end

Answer 7

end of the peptide that had the COO- group

Question 8

alpha-carbon

Answer 8

central backbone atom of the amino acid

Question 9

beta-carbon

Answer 9

first carbon atom of the side chain

Question 10

properties associated with identifying amino acids

Answer 10

polarity, charge, hydrogen bonding ability

Question 11

which amino acids are isomers

Answer 11

leucine and isoleucine

Question 12

amino acids with very non-polar side chains

Answer 12

A, V, L, I, M, F
- side chains consist of C-C and C-H bonds
- side chains are hydrophobic

Question 13

what causes polarity

Answer 13

atoms having different electronegativity
- atoms with similar electronegativity are non-polar

Question 14

most to least polar elements found in amino acids

Answer 14

O > N > S > C = H

Question 15

polar bonds

Answer 15

when one atom in covalent bonds hogs more than 50% of electrons leading to unbalanced charges

Question 16

moderately non-polar amino acids

Answer 16

G, C, P, Y, W
- have both polar and non-polar properties

Question 17

polar uncharged amino acids

Answer 17

S, T, N, Q
- good hydrogen bond donors and acceptors

Question 18

hydrogen bonds

Answer 18

electrostatic attractions between H-bond donor and acceptor

Question 19

H-bond donors

Answer 19

Highly polar -OH or -NH groups, donates its H for hydrogen bonds (slightly positive)

Question 20

H-bond acceptors

Answer 20

electronegative atom with an available lone pair of electrons such as O or N (slightly negative)

Question 21

maximum strength in H-bonds

Answer 21

directional-best if donor and acceptor line up with one another

Question 22

do H-bonds cause molecules R1 and R2 to form a permanent link?

Answer 22

no, they just stick loosely

Question 23

Polar positive amino acids

Answer 23

H, L, R
- side chains contain weak bases that gain H+ (become protonated)

Question 24

polar negative amino acids

Answer 24

D, E
- side chain contains have carboxylic acid group that loses H+ (become deprotonated)

Question 25

free amino acids

Answer 25

weak electrolytes due to their amino and carboxylate groups