Biochem

Question 1

Where do D amino acids exist

Answer 1

prokaryotes

Question 2

Nonpolar, nonaromatic amino acids

Answer 2

glycine, alanine, valine, leucine, isoleucine, methionine, proline

Question 3

Aromatic amino acids

Answer 3

tryptophan, phenylalanine, tyrosine

Question 4

Polar Amino acids

Answer 4

Serine, threonine, asparagine, glutamine, cysteine

Question 5

Negatively charged amino acids

Answer 5

aspartate, glutamate

Question 6

Positively charged amino acids

Answer 6

lysine, arginine, histidine

Question 7

Nature of amino acid at low PH

Answer 7

fully protonated

Question 8

Nature of Amino acid at high PH

Answer 8

fully deprotonated

Question 9

Nature of Amino Acid at isoelectric point

Answer 9

zwitterion

Question 10

PI of amino acids without charged side chains

Answer 10

6

Question 11

peptide formation is what type of reaction

Answer 11

dehydration

Question 12

conjugated proteins

Answer 12

have attached molecules called prosthetic groups which can be metal ions, vitamins, lipids, carbs, or nucleic acids

Question 13

Oxidoreductase

Answer 13

catalyzes REDOX reactions

Question 14

transferase

Answer 14

move a functional group from one molecule to another

Question 15

hydrolase

Answer 15

cleaves with water

Question 16

lysase

Answer 16

cleaves without water

Question 17

isomerase

Answer 17

interconversion of isomers including constitutional isomers and stereoisomers

Question 18

how do enzymes work

Answer 18

by stabilizing the transition state

Question 19

Michaelis Mentin Plot info

Answer 19

plots substrate concentration (x) and reaction velocity (y)
Km value occurs at 1/2 vmax

v = (vmax[s])/(Km+[S])
vmax = [E]kcat
v=(Kcat/Km +[S])[E][S] but at low substrate concentration S can be negated and the equation is v=(Kcat/Km)[E][S]

Question 20

Lineweaver-Burn Plot info

Answer 20

plots 1/v (y) against 1/[S] (x)

x intercept is (-1/Km) Y intercept is (1/vmax)

Question 21

Catalytic Intensity

Answer 21

Kcat/Km

Question 22

Hills coefficient

Answer 22

describes cooperative binding. Above one indicates cooperative binding, below one indicates negative cooperative binding, a value of 1 indicates no cooperative binding

Question 23

Competitive inhibition

Answer 23

when inhibitor is similar to subtrate and binds to active site. Can be overcome by adding more substrate. Has no effect on vmax, but Km increases

Question 24

Noncompetitive inhibition

Answer 24

inhibitor binds with equal affinity to enzyme and enzyme-substrate complex. Vmax is decreased Km stays the same

Question 25

Mixed inhibition

Answer 25

inhibitor with unequal affinity for enzyme and enzyme substrate complex. Vmax is decreased and Km increases or decreases depending on the inhibitors affinity

Question 26

uncompetitive inhibition

Answer 26

inhibitor only binds with enzyme-substrate complex so both Km and vmax decrease

Question 27

zymogens

Answer 27

inactive forms of an enzyme that are activated by cleavage

Question 28

Migration velocity

Answer 28

v=Ez/f

Question 29

Cadherins

Answer 29

calcium dependent glycoproteins hat hold similar cells together

Question 30

integrins

Answer 30

have two membrane spanning chains to permit cells to adhere to extracellular proteins

Question 31

selectins

Answer 31

allow cells to adhere to carbohydrates on surfaces of other cells. found in the immune system

Question 32

antibody makeup

Answer 32

two heavy chains and two light chains held together by disulfide linkages and noncovalent interactions

Question 33

G protein receptor cascade

Answer 33

Ligand engages G protein. GDP becomes GTP and the alpha subunit dissociates from beta and lambda subunits. Alpha subunit activates adenyl cyclase or phospholipase C and GTP becomes GDP and alpha subunit reassociates.

Question 34

Equation for number of stereoisomers with common backbone

Answer 34

=2^n where n is the number of chiral carbons

Question 35

Benedicts reagent

Answer 35

oxidizes glucose to gluconic acid and creates red precipitate to test for the presence of aldehyde

Question 36

Tollens reagent

Answer 36

makes a silvery substance when reacted with an aldehyde

Question 37

Esterification of glucose reagents

Answer 37

acetic anhydride, 273K, pyridine

Question 38

Phosphorylation of glucose

Answer 38

ATP usually occurs with an enzyme

Question 39

maltose

Answer 39

(glucose-alpha-1,4-glucose)

Question 40

cellobiose

Answer 40

beta 1,4 linkage of two glucose molecule

Question 41

Sucrose

Answer 41

(glucose-alpha-1,2-fructose)

Question 42

Lactose

Answer 42

(galactose-beta-1,4-glucose)

Question 43

cellulose

Answer 43

string of cellubiose (beta 1,4 linkage of two glucose molecule)

Question 44

Amylopectin

Answer 44

amylose but also has alpha1,6 bonds | amylose is glucose-alpha-1,4-glucose

Question 45

amylose

Answer 45

glucose-alpha-1,4-glucose

Question 46

glycogen

Answer 46

highly branched glucose polymer with alpha1,6 bonds more than amylopectin. Highly branched

Question 47

saturated fatty acid

Answer 47

has only single bonds (thus saturated with hydrogen)

Question 48

unsaturated fatty acid

Answer 48

has some double bonds

Question 49

glycerophosphate

Answer 49

As a head group (x) linked to a glycerol backbone via a phosphodiester linkage. Called phosphatidyl-x. examples include phosphatidylcholine and phosphatidylethanolamine

Question 50

sphingolipids

Answer 50

have a sphingosine backbone with long chain nonpolar fatty acid tails and polar head groups. Can be phospholipids or glycolipids.

Question 51

Classes of sphingolipids

Answer 51

ceramides, sphingomyelin, glycosphingolipids, gangliosides

Question 52

ceramides

Answer 52

sphingolipid with Hydrogen as a head group

Question 53

sphingomyelin

Answer 53

sphingolipids that are also phospholipids. Usually have phosphatidylcholine or phosphatidylethanolamine as the head group