Baker Exam 1

Question 1

Glycine

Answer 1

Gly, G

Non-polar, uncharged

Question 2

Alanine

Answer 2

Ala, A

Non-polar, uncharged

Question 3

Valine

Answer 3

Val, V

Non-polar, uncharged

Question 4

Leucine

Answer 4

Leu, L

Non-polar, uncharged

Question 5

Isoleucine

Answer 5

Ile, I

Non-polar, uncharged

Question 6

Proline

Answer 6

Pro, P

Non-polar, uncharged

Question 7

Phenyalanine

Answer 7

Phe, F

Non-polar, uncharged

Question 8

Tryptophan

Answer 8

Trp, W

Non-polar, uncharged

Question 9

Cystine

Answer 9

Cys, C

Non-polar, uncharged

Question 10

Methionine

Answer 10

Met, M

Non-polar, uncharged

Question 11

Serine

Answer 11

Ser, S

Polar, uncharged

Question 12

Threonine

Answer 12

Thr, T

Polar, uncharged

Question 13

Asparagine

Answer 13

Asp, N

Polar, uncharged

Question 14

Glutamine

Answer 14

Gln, Q

Polar, uncharged

Question 15

Tyrosine

Answer 15

Tyr, Y

Polar, uncharged

Question 16

Aspartic acid

Answer 16

Asp, D

Polar, acidic, charged

Question 17

Glutamic acid

Answer 17

Glu, E

Polar, acidic, charged

Question 18

Histidine

Answer 18

His, H

Polar, basic, charged

Question 19

Lysine

Answer 19

Lys, K

Polar, basic, charged

Question 20

Arginine

Answer 20

Arg, R

Polar, basic, charged

Question 21

How is the basic secondary structure of an alpha helix formed?

Answer 21

Hydrogen bonding between the C=O and N-group of the backbone amino acids form a coiled structure

Question 22

How is the basic secondary structure of the beta pleated sheet formed?

Answer 22

Hydrogen bonding between the C=O and N-groups of the backbone amino acids form a sheet-like arrangement

Question 23

What are super secondary structures connected by?

Answer 23

Flexible regions called “linkers” that are also functional

Question 24

What are super secondary structures

Answer 24

Secondary variants but not exactly tertiary structures

Question 25

What are beta meanders?

Answer 25

3 antiparallel beta sheets

Question 26

What are greek keys?

Answer 26

4 antiparallel beta sheets

Question 27

What is a helix-loop-helix?

Answer 27

Alpha helix then a loop and another alpha helix at a specific angle

Question 28

What does the purine salvage pathway utilize?

Answer 28

The HGPRT rxns to collect hypoxanthine and guanine to recombine then with PRPP to form nucleotide

Question 29

What is formed when hypoxanthine combines with PRPP?

Answer 29

IMP

Question 30

What is form when guanine combines with PRPP?

Answer 30

GMP

Question 31

What does xanthine oxidase do in purine carabolism?

Answer 31

Converts hypoxanthine into xanthine | Further converts hypoxanthine into uric acid which is expelled in urine

Question 32

What does guanine deaminase do in purine catabolism?

Answer 32

De-aminates guanine to form xanthine | Xanthine can be converted to uric acid and expelled by urine

Question 33

What is the intermediate product before conversion to uric acid?

Answer 33

Xanthine

Question 34

What is the final product of purine catabolism?

Answer 34

Uric acid

Question 35

What occurs in gout?

Answer 35

Build up of uric acid crystals

Question 36

What does allopurinol do?

Answer 36

Inhibits xanthine oxidase which allows more soluble xanthine and hypoxanthine to be dispelled

Question 37

What is an operon?

Answer 37

Cluster of genes under transcriptional control by one promoter

Question 38

What is the operator?

Answer 38

Regulatory region

Question 39

Polycystronic mRNA

Answer 39

Encodes for more than one protein

Question 40

Describe the lac operon

Answer 40

Allows regulation of a group of genes with common function

Question 41

What is the LacP?

Answer 41

The promoter for the lac operon

Question 42

What are the three structural genes for the lac operon?

Answer 42

LacZ (b-glactosidase - regulation) LacY (lactose permease) LacA (galactosidase transacetylase)

Question 43

What are the two regulatory sites on the lac operon?

Answer 43

``` LacO (operator site, provides binding for repressor) CAP site (activator protein for repressor protein) ```

Question 44

Lacl gene

Answer 44

Codes for the lac repressor protein | Considered a regulatory gene b/c sole function is to regulate other's gene expression

Question 45

What occurs when lactose is absent?

Answer 45

Lac repressor protein binds to nucelotides of lac operator site which prevents RNA pol from transcribing the Lac structural genes

Question 46

What occurs when lactose is present?

Answer 46

Allolactase is a small effector molecule 4 allolactose molecules bind to lac repressor protein to prevent binding to lacO Induction occurs and lac operon is induced

Question 47

Describe the CAP activator

Answer 47

Catabolite activator protein Positive control of transcription Operon is turned off when CAP is not bound

Question 48

What binds to CAP to induce complex binding?

Answer 48

cAMP | Results in bend in DNA that enchances RNA pol binding

Question 49

What inhibits the production of cAMP thus preventing binding of CAP to DNA?

Answer 49

Glucose

Question 50

What happen to lac if lactose and glucose are high?

Answer 50

Lac operon is shut off Glucose causes cAMP levels to drop CAP doesn't activate transcription Bacteria uses one sugar at a time

Question 51

What happens to lac when lactose is high but glucose is low?

Answer 51

``` Lac operon is turned on Allolactose levels rise Prevent lac repressor from binding to operator CAP bind to CAP site Bacteria used lactose ```

Question 52

What happen to lac when lactose in low and glucose is low or high?

Answer 52

Lac operon is shut off | Low lactose - lac repressor prevents transcription of lac operon