Test One cont Flashcards
1
Q
what does phenylisothiocyanate do
A
reacts with the alpha amino group on the amino terminal
2
Q
mucines are synthesized by
A
tracheobronchial, GI and genitourinary tract
3
Q
how does Ion-Exchange chromatography work
A
uses anion or cation charged beads to attract opposite charge and let other molecules go through solution
4
Q
thrombin can hydrolyze
A
peptide bond on carboxyl side of arg
5
Q
when his is changed to ser in fetus what does it reduce
A
affinity to 2,3-BPG
6
Q
what are the two models about states in hemo
A
concerted and sequential
7
Q
uncom inhib and Km
A
decrease
8
Q
what is a phospatidate
A
fatty acid, glycerol, phosphate
9
Q
what type of protein structure is formed when distant amino acids interact through weak bonds
A
tertiary
10
Q
glycolipid structure contains what instead of alcohol
A
sugar unit
glucose or galactose
11
Q
what are the enzymes called for the assembly of polysaccharides
A
glycosyltransferases
12
Q
glycoproteins units are called what
A
glcosaminoglycans
13
Q
competitive inhibitors
A
inhibitor reduces number of enzyme molecules available for substrate
14
Q
what are the side chain in the structure of hemoglobin
A
methyl, venyl, and propionate side chains
15
Q
misfolding in sickle cell anemia causes
A
aggregation process
16
Q
who discovered misfolded proteins
A
prusiner
17
Q
when Km is low
A
enzyme has more affinity to substrate
18
Q
what are glycoconjugates
A
glycoproteins
proteoglycans
glycolipids
19
Q
why does the pocket in R state disappear
A
structural transformation
20
Q
what are proteolytic enzymes
A
break peptide bonds using water
also hydrolyze ester bonds
21
Q
what is replaced in fetus for hemoglobin
A
beta chain replaced by gamma chain
22
Q
name of heme group
A
Fe-protoporphyrin IX
23
Q
hyalurona ex of
A
GAG, proteoglycan
non sulfated
part of extracellular matrix
24
Q
peripheral membrane proteins
A
bound mostly by electrostatic interactions with H bonds
25
can enzymes change the equilibrium of the reaction they catalyze
no but they can help reach equilibrium faster
26
how to determine D or L configuration in aldoses and ketoses
look at last OH group
L for Left side
D for right side
27
what configuration is all the Aldoses in
D
28
what enzyme is present if type B blood
glycosol transferase B
29
what is an intrinsically unstructured protein
no distinct 3D region
| assume a definite 3D structure upon interaction with other proteins
30
erythropoietin
glycoprotein hormone secreted by kidney and stimulate production of RBC when O2 level low
w/o glycosylation, hormone can only function at 10% of activity
31
more substrate means
faster the enzymatic reaction
32
epimers
isomers where the H and OH are flipped on one or more carbon atom
33
why can hemoglobin carry oxygen better than myoglobin
has 4 peptides, myo only one
| binds oxygen cooperatively meaning the binding of oxygen to one site will aid in binding to other sites more efficiently
34
what three interactions help the lipid membranes
hydrophobic
van der waals
hydrogen bonds
35
Km
is the concentration of the substrate at which the reaction velocity is half of the max
36
how does the entire glycosylation process take place
attaching entire glycosyl unit on a specialized lipid molecule called dolichol phosphate
37
penicillin binds to
transpeptidase, inhibits cell wall synthesis
38
why use SDS in gel electrophoresis
help break non covalent bonds
39
3 types of membrane lipids
phospholipids
glycolipids
cholesterol
40
what aa is changed into for hemoglobin in fetus
his to ser
41
looser packing in lipids means
less hydrophobic
42
sugars have to be what in order to react
activated
43
what type of functional group is a sphinosine
amino alcohol
44
4 components of phospholipids
one or more fatty acids
platform to which fatty acids attach to
phosphate
alcohol
45
statin
help reduce cholesterol by comp inhib key enzyme in cholestrol biosynthetic pathway
46
competitive inhibitors and Km
increase Km
47
function of chromatography
molecules interact differently with the stationary phase and mobile phase, thus can be separated from the rest
48
what is happening in relaxed state of hemo
looser subunits, more free O can bind but harder to release
49
what happens to proximal histidine in heme group
oxygen binds to it causing plane to change and overall tertiary structure
50
uncompetitive inhibitor
bind to enzyme substrate complex, binding site created only on complex
51
the transition state molecule is the least-_____ but highest in ____
stable
| free energy
52
what type of structure do membranes of lipids have
sheet like, 2 molecules thick
53
lipid function in cell
fuel
store energy
signal transduction messenger
part of membrane
54
what are the two structural form of hemoglobins
tense and relaxed
55
what are the three factors that affect fluidity in membrane
length of fatty acid
degree of unsaturation
cholesterol molecules
56
first histidine location in heme group is
proximal
57
ex of uncomp inhibitor
lithium and phosphoinositide cycle
58
what does the enzyme not affect
difference in free energy between substrate and product
59
function of enzymes
lower activation energy or facilitate the formation of the transition state
60
uncom inhib and velocity
decrease
61
who invented chromatography
Mikhail Tsvet
62
at low pH (high H+) hemoglobin tends to
release oxygen better
63
what are polysaccharides
glucose homopolymers
| disaccharide heteropolymers
64
trypsin can hydrolyze
peptide bonds for both Arg and Lys
65
so when glutamine is substituted by val what happens
val will interact with phe and val on beta chain causing misfolding
66
proteoglycans
carb constitute higher % of total weight
67
why are misfolded proteins deadly
they are infectious, influence other proteins to misfold
68
what are monosaccharides
aldehydes and ketones with OH groups
| small molecules composed of 3 to 9 carbon
69
what are metamorphic proteins
exist is different 3D structures that are usually in equilibrium with each other
70
aspirin binds to
cyclooxygenase, reducing synthesis of signaling molecules
71
what is happening in tense state of hemo
chains interacting closely, O is hard to bind but easy to release
72
what are cofactors
helper chemical to enzymes
73
what type of substitution occurs in sickle cell anemia
hydrophilic to hydrophobic
74
proteins and phospholipids can mover across membrane by
lateral motion
| transversing (only phospholipids) aka flip flop takes a few hours
75
what enzyme is present in type A blood
glycosol transferase A
76
structure of hemoglobin
four pyrrole rings linked by methine bridges to form tetra pyrrole ring
Fe in center bound to 4 N from rings
77
what is reversible inhibition
they dissociate relatively quickly
| comp, uncomp, mixed
78
mucines (mucoproteins)
mostly carb attached to protein through threonine and/or serine
79
at high CO2 concentration, the pH will be lower so the H+ concentration will be
high
80
what carb is usually in proteoglycans
GAG
81
function of mucine
protect cells against different environmental factors such as infection and chemical inhalation
large polymrs
82
which type of fate has the least hydrophobic interaction
oil
83
how does chromatography work
protein mixture added to porous gel matrix, small protein move through all the pores being slow and large proteins move faster
84
protein folding takes place as a what type of process
cooperative
85
the regulation of oxygen binding by hemoglobin is also regulated by
hydrogen ions and CO2
86
at high CO2 concentration, hemoglobin is likely to be in what conformation
tense
87
what type of effector is 2,3-BPG
allosteric, bind to hemo in different site from oxygen
88
in sickle cell anemia what aa is substituted
glutamine for valine on alpha chain
89
what denaturants reduce disulfide bonds
beta-mercaptoethanol
90
can enzymes catalyze impossible reactions
no
91
what is the function of distal histidine in heme group
prevents superoxide anion from leaving with electron
92
what does phosphorylating do to sugars
make them anionic, cannot cross membrane, not recognized by transporters
93
how can the competitive inhibitor be relieved
increase substrate concentration
94
heparin ex of
proteoglycan, GAG
| used for anticoagulant
95
what is the substrate of prostaglandin H2 synthase-1
arachidonic acid
| hydrophobic and cant leave membrane without binding to active site of protein
96
what is desalting
molecules moving from higher conc to lower conc
large particles stay in tubing
tubing put into buffer solution
97
what are GAG
large repeating units of modified disaccharides such as amino sugars and uronic acids
resistant to compression
98
what aa has glycosylation take place on
asparagine
serine
threonine
99
binding energy
the energy released upon the substrate binding to the active site of enzyme
100
mixed inhibitors
can bind simultaneously with substrate to enzyme, reduction of amount of functional enzyme
cannot be relieve by adding more sub
101
what are the membrane proteins
peripheral and integral
102
what is needed to break disulfide bonds in gel electrophoresis
beta-mercaptoethanol
103
how does H+ and pH affect oxygen binding i hemoglobin
the imidazole group of histidine either becomes charged or no charge and interacts with aspartate aa
104
what type of bond connects fatty acid to glycerol back bone
ester bond
105
furan is involved with
keto-hexoses
106
at high pH (low H+) hemoglobin tends to
not release oxygen
107
what are the two cofactors
metals and organic (coenzymes)
108
what happens when CO2 binds to N termini of peptide bond
forms negatively charged carbamate ion
109
hurler disease
accumulation of proteoglycans bc they are not degraded
110
function of agarose gel electrophoresis
DNA standards will allow researchers to estimate the size and concentration of unknown DNA
111
what does the negatively charged carbamate ion do in hemoglobin
stabilize T state and releases more oxygen
112
what type of bond is between active site and substrate
non covalent bond
113
what is phosphorylating sugars
key step in retaining sugars inside the cell
114
function of ES complex
bring substrate to the optimum orientation for a productive reaction to take place
115
as proteins move through the lumen of ER they get....
N-glycosylated
116
what are hemoglobins components
2 alpha helices and 2 beta chains
| binding: a1b1-a2b2
117
I-cell disease
enzymes missing for degradation of lysozome, enzymes were not properly glycosylated, secreted out into blood
debris remains in inclusion bodies
118
active site
substrate bind to enzyme
| collection of different aa from different parts of the enzyme
119
what is irreversible inhibition
bind tightly to enzyme and dissociate very slowly
| penicillin and aspirin
120
what are the 2 3D structures of lymphotactin
3 beta strands with alpha helix that binds to specific receptor
beta sheet that binds to glycosaminoglycan
121
holoenzyme
enzyme with cofactor
122
what are simple sugars
monosaccharide
disaccharide
oligosaccharide
123
proteins can absorb how much UV light if aromatic aa attached
280 nm
124
which bacteria has a thick peptidoglycan layer
gram positive
125
how do cells communicate to environment
proteins
126
how does the heme group stabilize after O is added to it
adding another histidine that forms H bond with O
127
what type of coenzymes are there?
```
prosthetic groups (tightly bound to enzyme)
loosely associated with enzyme
```
128
what is the transition state
middle molecule between substrate and product
| no longer sub but not yet product
129
mixed inhibitor and Km and Velocity
increase
130
what size fragments move faster in gel electrophoresis
smaller
131
fatty acids attach to sphinosine back bone by what bond
amide bond
132
what state of hemo is strongly favored
T state
133
why are aldoses reducing sugars
their free aldehyde group in the open configuration
134
oligosaccharides
monosaccharides linking with each other
135
alpha helix is characterized by
H bonds b/w amino acids on same strand with R groups projecting outward
136
what is added to to catabolic enzymes in golgi complex to make it to lysozome
mannose-phosphate
137
myoglobin is what type of protein
single polypeptide protein
138
pyran is involved with
aldo-hexoses
139
2 types of inhibition
reversible and irreversible
140
what happens with protein glycosylation in golgi complex
O-glycosylation
further modification of carb on protein
elaborating the N-glycosylated proteins
141
the is enzyme that glycosylate proteins with GlcNAc is called
GlcNAc transferase
142
what is the predominant acceptable model for membranes
the fluid mosaic model
143
at pH higher than 7.4 what happens to HIS in hemo
imidazole group loses charge and break interaction between asp aa, hold on to oxygen
144
membranes have what type of layer
lipid bilayers
145
what other aa is present in hemoglobin besides histidine
lysine
146
archea have what in their membrane that allows for harsher environment
ether bond instead of ester
| methyl group instead of H (which allows for more interaction b/w fatty acid tails to create stronger bonds)
147
what does the active site create
a unique microenvironment tailored for specific substrates and specific reactions
148
what kind of curve is present for hemoglobin
sigmoidal
149
the Fe in heme group can bind to
histidine
150
how does PrP misfold
native structure of alpha helices transforms into large beta sheets
151
what molecules have a hard time getting through lipid membranes
polar
152
what molecule plays an important role in modulating o binding in hemoglobin
2,3-biphosphoglycerate (2,3-BPG)
153
where is sphingomyelin found
in myelin sheath
154
competitive inhibitor and velocity
not affected
155
methotrexate competes with what enzyme
dihydrofolate and binds to dihydrofolate reductase
156
Prusiner discovered what protein that is misfolded
PrP
157
at pH lower that 7.4 what happens to His in hemo
imidazole group becomes charged allowing it to react asp which stabilizes T state and releases O more efficiently
158
how does T state transform to R state
bonds between 2,3-BPG and hemoglobin must break, more oxygen pressure must exist
159
what does the specificity depend on for binding in active site
precise arrangement of atoms
160
hemoglobin and myoglobin bond in what type of manner
cooperative
161
what is gel electrophoresis
proteins separated by mass only using a detergent
| use power source to drive protein from neg to pos side of gel
162
what does the enzyme affect
amount of free energy needed to initiate conversion of substrate to product
163
what is a cytokine
class of immune protein that bind to receptors on immune system cells to elicit specific immune responses
164
ex of membrane anchored protein
prostaglandin H2 synthase-1
165
function of carb
energy store, DNA and RNA synthesis
cell wall of bact and plant are oligosaccharides
link to protein and lipids to make more diverse
166
what is maximum velocity
saturation achieve
| all enzymes are being occupied
167
what is the aa sequence for for glycosylation
n-x-s or n-x-t
168
carb are made of
monosaccharides
169
where does CO2 bind to hemoglobin
N termini of peptide chain
170
enzymes can catalyze reactions at a rate of
10^6
171
integral membrane proteins
interact exclusively with the hydrocarbon core
172
glycoproteins
proteins constitute higher % of total weight
173
what denaturants destroy weak bonds
Heat, urea, SDS, pH
174
glycosylation occurs where
ER
| and golgi complex
175
who described the different parameters of enzymatic reactions
michaelis and menten
176
when is the maximum binding energy released
when substrate is in transition state
| max interactions between active site and enzyme
177
function of hemoglobin
four polypeptide protein
| carries oxygen from lungs to rest of body and CO2 and H+ back to lungs
178
ex of competitive inhib
methotrexate
179
dermatan sulfate ex of
proteoglycan, GAG
in skin, heart valves, blood vessels, tendon
preven infection, cardio disease, carcinogens
180
Lymphotactin is an example of
metamorphic proteins
| cytokine
181
what kind of bonds between membranes of lipids
non covalent
182
what happens in beta-thalasemia
no beta chains, all alpha chains
| alpha chains aggregate and precipitate leading to immature RBC
183
oxygen binding in hemoglobin is modulated by
CO2 and H+
184
glycosylation usually works with what
GlcNAc
185
glycoside mostly form what configuration
circular
186
apoenzyme
enzyme without cofactor
187
what are reducing sugars
aldoses
188
what happens in alpha-thalasemia
alpha chains not produced only 4 beta chains HbH
| HbH binds tightly to O2 causing poor delivery to tissues
189
when Km is high
enzyme has less affinity to substrate
190
what site is responsible for lowering the activation energy
active site
191
inhibitors
molecules that can inhibit enzymes by different mechanisms
| serve as control for enzymatic activity
192
where does 2.3-bpg bind in hemo
center during T state
193
what is the Bohr effect
how pH (h+) and CO2 affected binding of oxygen to hemoglobin
194
longer saturated fatty acid molecules have more hydrophobic interactions than shorter saturated fatty acid molecules
true
195
what is the term called that defines the difference between substrate and transition state
activation energy or gibbs free energy of activation
196
how can molecules pass through membrane
must shed interactions with water and form new ones with lipid core
197
what are the platforms in phospholipids that fatty acids attach to
glycerol
(phosphoglycerides)
sphingosine
(sphingolipids)
198
homopolymer
if a polysaccharide is composed of a single sugar
199
what are enzymes
biological catalyst
| catalyze reactions at faster rates
200
what chemical is needed for edman degradation
phenylisothiocyanate
201
what does chromatography mean
color writing
