biochemistry Flashcards
(128 cards)
1
Q
what is the energy storage form of lipids
A
triglycerides
2
Q
where are triglycerides stored
A
as fat droplets in adipose tissue
3
Q
what happens to triglycerides when blood glucose is low
A
triglycerides are hydrolysed
4
Q
what happens to triglycerides when fat is in excess
A
metabolised in the mitochondria to produce acetyl-CoA in TCA cycle
5
Q
are triglycerides high or low energy per yield
A
high
6
Q
what does cis mean
A
hydrogens are on the same side
7
Q
what does trans mean
A
hydrogen are on opposite sides
8
Q
what is budding
A
they recruit coat proteins and then can shed their coat leaving their receptor/ligand behind
9
Q
what is targeting and trafficking meditated by
A
Rab proteins of GTPase
10
Q
what is exocytosis
A
move out
11
Q
what is endocytosis
A
move in
12
Q
what is pinocytosis an example of
A
endocytosis
13
Q
what is phagocytosis an example of
A
endocytosis
14
Q
examples of energy
A
ATP
NADPH
15
Q
what produces most energy in human diet
A
- lipids
- polysaccharides
16
Q
where does glycolysis occur
A
in cytosol
17
Q
what does glycolysis produce
A
pyruvate
18
Q
what is the product of anaerobic conditions
A
lactic acid
19
Q
what happens to lactate
A
metabolised by the lier back into glucose by gluconeogensis
20
Q
what is the regeneration of lactate called
A
cori cycle
21
Q
what cycle does pyruvate enter under aerobic condition
A
TCA cycle
22
Q
in TCA cycle what happens to pyruvate
A
- decarboxylated to acetyl-CoA
23
Q
what happens to acetyl-CoA in TCA cycle
A
joins with oxaloacetate to form citrate
24
Q
how many reactions is TCA cycle
A
8
25
what is oxidative phosphorylation
movement of NADh and FADH2 through membranes to oxygen to produce water
energy released is used to efflux H+ set tun up a electrochemical gradient
26
what happens to the H+ electrochemical gradient
used for ATP synthesis through F0F1ATPase
27
what can failure to remove dysfunctional or misfiled proteins result in
- alzhemiers
| - dementia
28
what is a free radical
any atom or molecule that contains one or more unpaired electrons
making it more reactive
29
what are the major free radical species in the human body
- hydroxy radical (OH)
- superoxide radical (02-)
- nitric oxide (NO)
30
what makes up total body water
- intracellular fluid
- extracellular
- plasma
31
what is osmotic pressure
ability to hold water in the compartment
32
what does the intracellular fluid contain mainly
potassium
33
what does the extracellular compartment contain
- sodium salt
| - proteins
34
what is the capillary wall impermeable to
plasma proteins
35
what is the cell membrane impermeable to
sodium and potassium
36
what is the extracellular volume determine by
sodium concentration
37
what does a decreased extracellular volume do to cardiac output
decrease it
38
what filters most sodium
proximal tubule
39
what is responsible for day to day variation in sodium
aldosterone and ANP
40
what conditions cause sodium and water retention
- cardiac failure
- hepatic cirrhosis
- hypoalbuminaemia
41
what does a high dose of mineralocoroitcoid initially increase
renal sodium retention so that extracellular volume is increased
42
what does spironolactone do
block mineralocorticoid
43
what does the release of cardiac ANP require
optimum sodium concentration at the site of its action
44
what are changes in plasma sodium and osmolarity sensed by
osmoreceptors
45
what do osmoreceptors influence
thirst and release of ADH (vasopressin)
46
what does ADH play a role in
urinary concentration by increasing the water permeability
47
what does the absence of ADH do to water
means little water is reabsorbed in the collecting ducts
48
what are principal cells
have sodium and potassium channel in the apical membrane
49
what are intercalated cells
they do not transport sodium but have a role in hydrogen and bicarbonate handling
50
what is the name of water channels
aquaporins
51
what direction does water move in aquaporins
down an osmotic gradient
52
what happens to water channels when ADH has worn off
water channels are removed from the luminal membrane by endocytosis
53
what does ingestion of water cause
decreased release of ADH
54
what does a decrease in water reabsorption allow the water to go
excreted in dilute urine
55
what does water loss via sweat cause a rise in
both plasma osmolarity and ADH secretion
56
what disease can cause patients to become very thirsty
central diabetes insipidus
57
what are patients with central diabetes insipidus have a decrease in
ADH
58
when is a water load rapidly excreted
by inhibition of ADH release
59
what is another occasion where ADH is released
stress e.g. surgery or trauma
60
what does increased extracellular volume a result of
whole body salt retention
61
what is peripheral oedema caused by
expansion of the extracellular volume by at least 2L
62
where is peripheral oedema normal seen first
the ankles
63
what is lipodermatosclerosis
the skin is tethered and cannot expand to accommodate the oedema
64
when can oedema be noted in the face
in the morning
65
where does oedema accumulate in a patient in bed
in the sacral area
66
what other diseases does expansion of interstitial volume cause
- pulmonary oedema
- pleural effusion
- pericardial effusion
- ascites
67
what does expansion of the blood volume do
- raise JVP
- cardiomegaly
- added heart sounds
- basal crackles
- raised blood pressure
68
what is extracellular volume expansion due to
sodium chloride retention
69
what does reduction in cardiac output and a fail in effective circulatory volume to do RAAS
activates it
70
why is there peripheral vasodilatation in hepatic cirrhosis
due to increased NO generation
71
what is interstitial oedema a common clinical finding with
hypoalbuminaemia
72
what do oestrogen cause for sodium
mild sodium retention due to weak aldosterone like effect
reason for weight gain in premenstrual phase
73
what do mineralocorticoids and liquorice have
aldosterone like actions
74
what do NSAIDs cause
sodium retention in the presence of activation of RAAS
75
why may oedema result
from increased capillary pressure owing to relaxation of pre-capillary arterioles
76
what drug has a side effect of peripheral oedema
dihydropiridine calcium channel blocker
77
what drug can cure oedema
diuretics
but returns when they are stopped
78
where does loop diuretics act
in ascending limb of loop of Henle
79
examples of loop diuretics
- furosemide
| - bumetanide
80
where does thiazide diuretic act
early distal convoluted tubule
81
examples of thiazide diuretic
- bendroflumethiazide
| - metolazone
82
what do loop diuretics stimulate excretion of
both sodium chloride and water by blocking the sodium-potassium-2-chloride (NKCC2)
83
side effects of loop diuretics
- urate retention
- hypokalaemia
- decreased glucose tolerance
84
are thiazide diuretics more or less potent than loop diuretics
less potent
85
how do thiazide diuretics act
by blocking a sodium chloride channel in the distal convoluted tubule
86
example of aldosterone antagonist
spironolactone
87
when is spironolactone used
in patients with heart failure
88
do you need to administer lots of loop diuretic to work
yes
89
what causes decreased extracellular volume
loss of salt and water in a variety of ways
90
examples of how a patient may lose salt and water
- blood loss in haemorrhage
- vomiting
- diarrhoea
- fluid shift in sepsis
91
what can decrease extracellular fluid lead to
postural hypotension
92
symptoms of decreased extracellular water
- thirst
- muscle cramps
- nausea
- vomiting
- postural dizziness
- confusion
- coma
93
what does loss of interstitial fluid lead to
loss of skin elasticity
94
what does loss of circulating volume lead to
decreased pressure in the venous and arterial compartments
95
where is the fluid volume of the body controlled
kidneys
96
what does water follow
salt by osmosis
97
what is salt retention controlled by
RAAS
98
what happens if too much salt and water is retained
oedema
99
what is the best way to monitor volume status
measure their weight over a period of days
100
what is the osmolarity of the blood controlled by
kidneys
101
what does ADH react to
retain free water which dilutes the blood
102
what is the bodys sodium concentration determined by
the amount of free water
103
what is a decrease in conc of H+ termed
| rise in blood pH
alkalaemia
104
what is an increase in the conc of H+ termed
| decrease in pH
acidaemia
105
where is excess sulphate excreted
in the urine
106
what 3 cell types does the collecting duct have
- principal cell
- alpha-intercalated cell
- beta-intercalate cell
107
what do principle cells do under the influence of aldosterone
reabsorb Na+ and water and secrete K+
108
what is the primary source of ammonia
glutamine
109
what is deamination of ammonia catalysed by
glutaminase
110
what does deamination result in
alpha-ketogluutaric acid and ammonia
111
what is abnormal CO2 removal in the lungs termed
respiratory acidosis and alkalosis
112
what is the abnormality in the regulation of bicarbonate termed
metabolic acidosis and alkalosis
113
what does metabolic acidosis cause
hyperventilation leading to increased removal of CO2 in the lungs and partial compensation for the acidosis
114
what is respiratory acidosis accompanied by
renal bicarbonate retention
115
what are the ABG results in respiratory acidosis
```
pH = decreased
PaCO2 = increased
HCO3 = increased for compensated
```
opposite direction to pH
116
ABG results for respiratory alkalosis
```
pH = increased
PaCO2 = decreased
HCO3 = decreased
```
opposite direction to pH
117
ABG results for metabolic acidosis
```
pH = decreased
PaCO2 = decreased
HCO3 = decreased
```
same direction to pH
118
ABG results for metabolic alkalosis
```
pH = increased
PaCO2 = increased
HCO3 = increased
```
same direction to pH
119
what is respiratory acidosis caused by
retention of CO2
120
example of respiratory acidosis
COPD
121
what is respiratory alkalosis
increased removal of CO2
122
what causes respiratory alkalosis
hyperventilation
123
what is metabolic acidosis due to
accumulation of any acid other than carbonic acid
124
what disorders can lead to metabolic acidosis
- lactic acidosis during shock
| - impaired acid excretion
125
what is chronic acidosis a risk factor for
muscle wasting in renal failure
126
where is ammonia and H+ excreted
in the urine
127
what can tubular disease cause
bicarbonate wasting
128
when does ketoacidosis occur
in starvation and after alcohol overdose
