quiz 2 Flashcards
1
Q
what does protein do
A
perform biochemical functions
catalyzed biochemical reactions
2
Q
define protein
A
workhorse of life
made of amino acids by peptide bonds
3
Q
how many amino acids are ionize
A
7
4
Q
what groups make up an amino acid
A
amino group, carboxyl group, hydrogen, side chain
5
Q
which amino acid is not chiral
A
glycine
6
Q
which aminos are negative at pH 7
A
asp and glu
7
Q
which aminos are positive at pH7
A
lys, arg, leu, asn, gln
8
Q
which aminos are hydrophilic
A
ser, thr, cys
9
Q
which aminos are hydrophobic
A
gly, ala, pro, val, leu, ile, met
10
Q
which aminos are aromatic
A
phe, tyr, trp
11
Q
name this amino
A
glycine
gly
g
12
Q
name this amino
A
alanine
ala
a
13
Q
name this amino
A
valine
val
v
14
Q
name this amino
A
leucine
leu
L
15
Q
name this amino
A
isoleucine
ile
I
16
Q
name this amino
A
proline
pro
p
17
Q
name this amino
A
methionine
met
m
18
Q
name this amino
A
phenylalanine
phe
F
19
Q
name this amino
A
tryptophan
trp
w
20
Q
name this amino
A
tyrosine
tyr
Y
21
Q
name this amino
A
serine
ser
s
22
Q
name this amino
A
threonine
thr
T
23
Q
name this amino
A
cysteine
cys
C
24
Q
name this amino
A
aspartic acid
asp
D
25
name this amino
glutamic acid
glu
E
26
name this amino
asparagine
asn
n
27
name this amino
glutamine
gln
Q
28
name this amino
histadine
his
h
29
name this amino
histadine
his
h
30
name this amino
lysine
lys
k
31
name this amino
arginine
arg
R
32
describe primary structure
amino acid sequence
33
describe secondary structure
3D arrangements of polypeptide backbone
34
describe tertiary structure
folding and arrangement of secondary structures
35
describe quarternary structure
3D arrangement of separate polypeptide chains
36
what can primary structure be broken into
protease or peptidase
37
define residue
individual aminos in peptide chain
38
describe the 4 steps of enzyme catalysts
enzyme is available and empty
substrate binds to enzyme
substrate converts to product
products are released
39
define net charge
overall charge, depends on pH
40
define isoelectric point (pI)
average pH where molecule has no electric charge
41
define zwitterion
electroneutral molecule containing positive and negative charge
42
what is the equation of pI
(pKa1+pKa2)/2
43
what are the 7 ionizable groups
asp
glu
his
cys
tyr
lys
arg
44
describe proteins
flexible
noncovalent
always in motion
conformational changes
45
what are primary structures stabilized by
covalent bonds
46
what are the 3 secondary structures
a-helix
B-sheet
B-turn
47
describe a-helix
right-handed
3.6 residues per turn
contain n to n+4 H bonds
48
what are the side chain effects
interacts together
3-4 residues away
can be charged
bulkiness can cause steric hindrance
49
what is the helix breaker
proline
50
what makes a bad helix
glycine
51
helix has a…
overall dipole movement
52
what are amphiphatic helices used for
gating and fat hydrolysis
53
describe B-strand
extended polypeptide
side chain above and below backbone
an arrow pointing to C-term
54
describe B-sheet
side by side strands with H bonding
backbone is made of of N,H,O
can be parallel or antiparallel
55
describe B-turn
2 adjacent segments of antiparallel B-sheets
4 residues long
56
what allows for secondary structure to be possible
phi and psi rotation
57
what makes up phi
C’, N, Ca, C’
58
what makes up psi
N, Ca, C’, N
59
what are the factors of phi and psi
steric interference
H-bonding is maximized
with side chains, the phi angle of proline locks in
60
define rhamachandran plots
plots all phi and psi in a protein
61
what are the two main types of tertiary structures
globular
fibrous
62
describe globular proteins
spherical
soluble in H2O
hydrophobic core hydrophilic exterior
63
describe fibrous proteins
rod-shaped
insoluble in H2O
64
define domain
separate structural units of a protein
65
define desaturation
unfolding a protein
66
define renaturation
refolding a proteim
67
define disulfide
2 cysteine residues that interact after oxidation
a type of cross linking
68
what do enzymes do
catalyze rxns by lowering activation energy and increasing the rate of product formation
69
what do structural proteins do
maintains cell structure and allows it to change shape
forms polymers
70
what are examples of structural protein
actin
tubulin
collagen
71
what do cell signaling proteins do
transmit signals
72
describe nuclear receptors
regulate gene expression in response to ligand bonding
73
describe intracellular signaling proteins
molecular formation changes due to incoming signals
74
describe genomic caretaker proteins
maintain accessibility to genomic information
DNA repair, replication, recombination, and gene expression
75
describe transport protein
move molecules within and between cells
in plasma membrane
permit polar and charged molecules to pass
76
describe passive transport
energy independent
down the concentration gradient
77
describe active transport
requires energy (from ATP hydrolysis and ionic gradient)
up the concentration gradient
