biochemistry Flashcards
(102 cards)
1
Q
name 2 polysaccharides
A
cellulose and glycogen
2
Q
free energy chain equation
A
ΔG = ΔH – TΔS
3
Q
exergonic reaction
A
total free energy of products < reactants
4
Q
ΔG in exergonic reaction
A
negative
5
Q
what reactions can occur spontaneously
A
exergonic
6
Q
what is the net gain of ATP in glycolysis
A
2
7
Q
how many ATP molecules are generated in glycolysis
A
4
8
Q
what is Gluconeogenesis
A
Making new glucose from non-carbohydrate precursors, e.g. pyruvate
9
Q
what reactions are used as control points
A
with large negative ΔG values
10
Q
given an example of a catabolic pathway
A
glycolysis
11
Q
give an example of an anabolic pathway
A
gluconeogenesis
12
Q
what is stronger -H or covalent bonds
A
covalent
13
Q
which amino acids is neither in D or L configuration
A
glycine
14
Q
what are D and L forms
A
stereoisomers
15
Q
describe peptide bonds
A
planar
partial double bond character
16
Q
what does the HH equation do
A
calculate the properties of a buffer solution
17
Q
what are zwitterions
A
amino acids without charged side groups
18
Q
what is isoelectric pH
A
the pH at which a molecule has no net charge
19
Q
given an example of a protein acting as a buffer
A
Hb in blood
20
Q
what angles can the polypeptides rotate around
A
a carbon and amino group
a carbon and carboxyl group
21
Q
what side is the a helix handed
A
right
22
Q
what do proline residues do to a helix
A
break them
23
Q
what are the turns between β sheets strands
A
glycine and proline
24
Q
what protein has different 2y structure elements
A
phosphoglycerate kinase
25
what is tropocollagen
the molecular component of collagen
26
what does tropocollagen consist of
3 polypeptide chains coiled around eachother
27
what does covalent crosslinking in collagen do with age
inc
28
what does scurvy result in
weakened collagen - bleeding gums
29
fibrous proteins
contain polypeptide chains organised parallel long a single axis
30
fibrous protein exampple
keratin and collagen
31
globular proteins
spherical shape
32
globular proteins exmaples
myoglobin and Hb
33
name some forces stabilising 3y structures
```
Covalent disulphide bonds
Electrostatic interactions = salt bridges
Hydrophobic interactions
Hydrogen bonds
Complex formation with metal ions
```
34
what does sickle cell anaemia result from
a change from glutamic acid to valine
35
what does sickle cell anaemia result in
rigid sickle shape cells - can block blood flow in capillaries
36
what results from incorrect protein folding
alzheimers, parkinsons, CJD
37
what is mad cow disease caused by
infection
38
what is CJD caused by
spontaneous or inherited mutation
39
what is CJD caused by
prion proteins
40
where are new nucleotides only added
to a free 3' end
41
how many bonds between A and T
2
42
how many bonds between C and G
3
43
what is dna replication catalysed by
dna polymerase
44
what are the properties of DNA polymerase
can only add to existing nucleic acids
can not start DNA synthesis on their own
require an RNA primer to start replication
45
how is the lagging strand replicated
Okazaki fragments
46
what unwinds teh DNA
helicase
47
what is the RNA primer for DNA polymerase synthesized by
primase
48
what is the proofreading system that DNA polymerase has
3' to 5' exonuclease activity that removes incorrect nucleotides
49
what does RNA contain
stem loops
50
what does tRNA have
an anticodon
51
what is the bonds that hold together primary protein structure
peptide (covalent)
52
what does a-amanitin do to RNA polymerase II
inhibits it
53
which type of RNA polymerase synthesises all mRNA
Pol II
54
how does transcription begin
binding of TFIID to TATA box
55
what does TFIID
introduce kink into DNA and provide a landing platform fro further transciption factors and RNA polymerase
56
does RNA polymerase require a primer
no
57
what is the new RNA sequence to the template strand
complementary
58
what is the new RNA to the coding strand
identical
59
how are steroids transported in blood
bound to albumin or other proteins
60
what is added to the end of mRNAs
poly A tail and 5'cap
61
how are free ribosomes translocated
post translationally
62
how are bound ribosomes in RER translocated
co translationally
63
how do enzymes reduce the activation energy
provide alternative pathways
64
what is an apoenzyme
enzyme without a cofacotr
65
what is a holoenzyme
enzyme with a cofactor
66
what are tightly bound coenzymes called
prosthetic groups
67
what are metalloproteins
Metal cofactors form a metal co-ordination centre in the enzyme
68
what do vitamins function as
coenzymes
69
what are isozymes
isoforms of enzymes that catalyse the same reaction but have different properties and structure
70
what does lactate dehydrogasne do in the heart and muscle
H (Heart) – promotes aerobic metabolism
| M (Muscle) promotes anaerobic metabolism
71
what enzyme carries out phosphorylation reactions
kinases
72
what are zymogens
inactive precursors of enzyme
73
what is Km
half V max
74
what is the intersection with x axis in Lineweaver-Burk plot
Km
75
what is the intersection with y axis in Lineweaver-Burk plot
Vmax
76
what has a higher affinity for glucose - hexokinase or glucokinase
hexokinase - lower Km
77
what does a low Km suggest
high affinity of enzyme for its substrate
78
do allosteric enzymes follow MM kinetics
no - sigmoidal curve
79
where is GLUT3 found
brain
80
where is GLUT1 found
brain
81
what is glycolysis
conversion of glucose to pyruvate
82
name 3 control points in glycolysis
hexokinase
Phosphofructokinase
pyruvate kinase
83
what does hexokianse control
substrate entry
84
what does Phosphofructokinase control
rate of flow
85
what does pyruvate kinase control
product exit
86
how is Phosphofructokinase controlled
energy change
87
what is used to ferment pyruvate to lactic acid
NADH
88
what is the Warburg effect
upregulation of anaerobic glycolysis in cancer cells - produce energy
89
what must happen to NADH for glycolysis to continue
re oxidised - NAD+ is regenerated through the oxidative metabolism of pyruvate
90
where does the TCA cycle occur
mitochondria
91
TCA cycle - overall production
3 NADH
FADH2
2 CO2
GTP
92
what is the enzyme of the TCA cycle that is not located in the mitochondrial matrix
succinate dehydrogenase - inner mitochondrial membrane
93
what is the yield of one molecule of glucose
```
4 ATP
10 NADH
10 H
2 FADH2
4 CO2
```
94
what does pyruvate dehydrogenase deficiency result in
poor muscle tone
retardation and seizures
resp problems
95
where are ketone bodies formed
liver
96
are ketone bodies acid or alkali
strongly acidic
97
what is diabetic ketoacidosis
Hyperventilation with a severe metabolic acidosis.
98
what allows NADH from the cytoplasm to cross the inner mitocondrial membrane
malate aspartate shuttle
99
what does a negative electron transport potential mean
reduced form of X has a lower affinity for electrons than H
100
which resp complex doesn't pump H
II
101
what is ATP synthase also called
F1F0ATPase
102
which part of ATP synthase protrudes into the mitochondiral matrix
F1
