C4 Protein Flashcards Preview

Biol 3310 > C4 Protein > Flashcards

Flashcards in C4 Protein Deck (82):
1

Catalyzes formation or breakage of covalent bonds

Enzyme

2

Binds to DNA to switch genes on or off

Gene regulatory protein

3

Generates movement in cells and tissues

Motor protein

4

Used by cells to detect signals and transmit them to the cell's response machinery

Receptor protein

5

Each succesive amino acid adds to the ? end of a peptide

carboxyl

6

Primary structure of protein?

amino acid sequence

7

Bond between amino acids in a protein

peptide

8

alpha-helix and beta-sheets are (1*,2*,3*) structures of Proteins

2*

9

Denatured protein in water using urea. Then observed conformation reformed upon removal of urea.

Anfrinson

10

Anfrinson determined..

amino acid sequence determines structure

11

The CAP protein has one large, and one small ?

domain

12

Any segment of a polypeptide chain that can fold independently into a compact, stable structure

domain

13

The secondary structure of proteins is generally a result of ?

H-bonding

14

The tertiary structure of proteins is a result of ?

side chain interactions

15

proteins with similar structure but different function

protein families

16

proteins made of four subunits

tetramer

17

dimer of the same two polypeptides

homodimer

18

hemoglobin is a dimer of ?

heterodimers

19

Simple, elongated, three-dimensinal protein

fibrous

20

myosin has this structure

coiled coil

21

Proteins bind their ? with great specificity

ligands

22

What is meant by high affinity binding?

The ligand with a higher affinity will be present in the binding region more readily than one with a low affinity

23

Enzyme binds to ? of substrate

transition state

24

hydrolases

catalyze hydrolytic cleavage

25

nucleases

hydrolysis of nucleic acids (cleaves phosphodiester bonds)

26

proteases

hydrolysis of proteins (breakdown peptide bonds)

27

kinase

phosphate transfer

28

phosphatase

hydrolytic removal of phosphate

29

ATPases

hydrolyze ATP

30

Three ways in which enzymes lower activation energy

1) binds and orients two substrates to encourage reaction 2) rearrange electrons within substrate 3) strains substrate into transition state

31

factors affecting enzyme activity

temp, ph, substrate concentration, inhibitors/activators

32

[ES] x k_cat

V

33

michaelis-menton equation. V=?

V_max x ( [S] / ( [S] + K_m ) )

34

Achieved when enzyme is saturated with substrate

V_max

35

Reaction velocity when the substrate concentration is at the K_m

V_max / 2

36

K_m =

(k_off + k_cat) / (k_on)

37

Michaelis-menten plot is a plot of ? vs ?

concentration vs velocity

38

lineweaver-burke plot is a plot of ? vs ?

1/concentration vs 1/velocity

39

the x intercept of a lineweaver burke plot is equal to

-1/K_m

40

the y intercept of a lineweaver burke plot is equal to

1/V_max

41

slope of a lineweaver burke plot is equal to

K_m / V_max

42

inhibitors that bind so tightly to an enzyme that they "kill" it

irreversible

43

bind to active site or compete with the normal substrate

competitive inhibitors

44

changes the conformation site of the enzyme and interferes with its ability to catalyze

noncompetitive inhibitor

45

a competitive inhibitor reduces ?

k_on

46

a noncompetitive inhibitor reduces ?

k_cat

47

a ? inhibitor gives a new V_max

noncompetitive

48

On a L-B plot, a ? inhibitor has a different x-intercept

competitive

49

On a L-B plot, a ? inhibitor has a different y-intercept

noncompetitive

50

A ? inhibitor requires more substrate to get to its original V_max

competitive

51

Enzymes that undergo a conformational change between active and inactive forms

allosteric

52

What effect do allosteric effectors have on allosteric enzymes

change equiibrium

53

Are synthesized as inactive precursors that require modification

zymogens

54

What usually modifies zymogens

proteolytic cleavage

55

A common mechanism for turning a protein on or off

de/phosphorylation

56

Act as molecular timers

GTP-binding proteins

57

How do GTP-binding proteins act as molecular timers

after hydrolysis of GTP, a slow step occurs where GDP dissociates before another GTP can attach

58

EF-Tu is an example of this kind of protein

GTP-binding

59

Function of EF-Tu

binds tRNA to ribosome

60

hydrolysis of EF-Tu (attaches/releases) it to/from tRNA

releases

61

A non-nucleic acid infectious disease

PrP

62

if it takes one second for a molecule to move 1um, how long does it take to travel 10um?

100 seconds

63

how does an alpha helix form

NH of every peptide bond is H-bonded to the C=O of peptide bond located 4 AA's away

64

CAP small domain binds to ?

DNA

65

CAP large domain binds to ?

cyclic AMP

66

Serine protease family (3)

elastase, chymotrypsin, trypsin

67

Proteins secreted by the cell to form gel-like matrix

Fibrous

68

Three fibrous proteins

keratin, collagen, elastin

69

collagen structure

triple helix

70

elastin structure

covalently crosslinked

71

keratin structure

coiled coil

72

target of antibody called ?

antigen

73

hexokinase add phosphate to ? but ignores ?

D-glucose, L-glucose

74

model enzyme

lysozyme

75

lysozyme function

severs polysaccharide chains of cell walls of bacteria

76

rhodopsin

non protein component of a rhodopsin protein that detects light

77

Three methods of enzyme control

production of enzyme. compartmentalization of enzyme. enzyme itself (inhibitors, temp, ph)

78

Amount of enzymes phosphorylated at any one time

1/3

79

set of covalent modifications a protein contains at any moment

regulatory protein code

80

in vitro literally mean?

in glass

81

in vivo literally means

in the living

82

How is protein AA sequence determined

breaking polypeptide with selective proteases