Biochem quiz 1 - Amino acids

Question 1

Acidic Amino acids

Answer 1

Apsartic acid, glutamic acid

Question 2

non polar alipathic AA

Answer 2

glycine, alanine, valine, proline, leucine, isoleucine

Question 3

branched non polar alipathic AA

Answer 3

leucine, isoleucine, valine

Question 4

Polar uncharged AA

Answer 4

serine, threonine, aspargine, glutamine

Question 5

sulfur containing R group

Answer 5

methionine, cysteine

Question 6

Negatively charged AA R group

Answer 6

glutamate, aspartate

Question 7

Positively charged R group

Answer 7

Histidine, lysine, Arginine

Question 8

aromatic AA

Answer 8

tyrosine, phenylalanine, tryptophan

Question 9

which substances have L configuration?

Answer 9

Amino acids

Question 10

Which substances have D configuration?

Answer 10

all sugars metabolized in the body, such as ribose , have D configuration

Question 11

zwitterion

Answer 11

neutral molecule with a positive and negative charge

NO NET CHARGE

Question 12

isoelectric point

Answer 12

point at which there is no net charge

Question 13

if ph is less than 2 for pk1, what charge will exist?

Answer 13

+1

Question 14

if ph is greater than 10 for pk2, what charge will exist?

Answer 14

-1

Question 15

how do you solve for the PI?

Answer 15

average of the two ionizable groups of an amino acid

Question 16

Abbreviations of AA’s

Answer 16

Question 17

post translational modification to proteins, types:

Answer 17

carb addition, lipid addition, regulation, modfied AA

Question 18

what is phosphorylation, what AA take part in this?

Answer 18

OH side chain required, Serine, threonine, tyrosine

adds hydroxyl group , phosphate group gets added. adds negative charge, Kinases add phosphate groups.

Question 19

acetylation

Answer 19

NH2 of lysine terminus

proteins that bind to DNA

Question 20

ADP ribosylation

Answer 20

N of Arg, gln, S of cysteine

Question 21

Modified amino acids : Oxidation

Answer 21

lysine, proline

Question 22

Modified AA Carboxylation

Answer 22

glu

Question 23

chiral

Answer 23

4 different substituents , rotate polarized light, ALL chiral AA’s are of the L configuration

Question 24

which AA does not have a chiral center?

Answer 24

Glycine, 2 H side chains

Question 25

When carb. acid loses a proton it becomes_____ charged.

Answer 25

Negatively charged, increasing PH, therefore, - charge. If ph decreases, gaining protons. If pH increases. losing protons.

Acids want to donate protons, become more ACIDIC

Question 26

When Amino group picks up a proton, it becomes _____ charged.

Answer 26

positive . Gaining more H protons, decreasing pH

Bases want to gain/accept more protons, become more Basic.

Question 27

basic vs acidic

Answer 27

base- proton acceptor

acid- proton donator

Question 28

What is the best type of buffer? What pH/pka?

Answer 28

The best buffer is when the pH is closest to the pKa

Question 29

post translational modification helps to do what?

Answer 29

Anchor proteins to the membrane

Question 30

lipid chains , what is on inside and outside?

Answer 30

polar chains on outside, greasy acyl chains on interior

Question 31

Role/ importance of Disulfide bonds

Answer 31

link cysteine molecules together

link peptide hormones together in the blood

Question 32

What tool is used to detect AA’s?

Answer 32

Chromatography

AA absorb UV light, higher peak means more of a certain AA, changes in levels of AA can help detect disease

Question 34

proline is an_________ acid

Answer 34

IMino

Question 35

ionizable group pka’s

acidic AA

Answer 35

around 4. for aspartate and glutamate

Question 36

pKa for arganine and lysine:

Answer 36

12.5 and 10.5

Question 37

pka for histidine

Answer 37

6

Question 38

pka for cysteine and tyrosine

Answer 38

8.4 and 10.5