Biochemistry Flashcards
What happens to arterial PCO2 in normal pregnancy?
Normal ABG in non-pregnant adult?
It reduces
Non-pregnant
pH 7.35 - 7.45 / CO2 4.7 - 6 / HCO3 22-26
Pregnant
pH: 7.4 - 7.47 / CO2 4.1 / HCO3 19-20
At what phase of eukaryotic cell division can the cell go into a quiescent stage?
G0
[G0] <-> G1 - S - G2 - Mitosis (PMAT
condense/align/separate/envelope) –>
Dexa scan result ranges
normal
osteopenia
osteoporosis
normal > -1 (eg -0.5)
Osteopenia -1 to -2.5
Osteoporosis < - 2.5 (e.g. -2.9)
Oestrogens in order from least to most potent
Estriol –> Estrone –>Estradiol
What process occurs exclusively in the mitochondria?
Oxidative phosphorylation
82% of Estradiol binds to what in the blood?
Albumin
What mechanism is required for myometrial contraction?
Elecrtron transport chain
What does the Golgi apparatus do?
Package proteins into membrane bound vesicles
At what stage in the cell cycle is mitosis arrested if there is a chromosomal abnormality?
G1
Text book:
DNA damage check points in G1, S, G2
and spindle checkpoint in metaphase
Google
‘Arrest in G1 prevents aberrant replication of damaged DNA, and arrest in G2 allows cells to avoid segregation of defective chromosomes.’
Where in the kidney is the majority of bicarbonate reabsorbed
PCT
What cell type secretes calcitonin?
C-cells of thyroid gland
What is the most abundant oestrogen in pregnancy?
Estriol
List the the estogens in the order of their activity on the vaginal mucosa
Estradiol-estrone-estriol
This is the same as strongest to weakest
A baby had bradycardia and was delivered by ventouse
Umblical artery blood
PH 7.05, base excess -4
Umbilical venous blood
PH 7.25, base excess -2.5
Interpretation?
The baby had an ecute episode of hypoxia before delivery
Normal arterial range
*pH 7.10 - 7.38
Normal venous range
pH 7.2 - 7.44
(found online)
What is the Z score
A Z-score compares bone density to the average values for a person of the same age and gender
A phase of the cell cycle where DNA replication occurs / controls mutation of genes:
S phase
most important anion in urine
Chloride
Same as in ECF
Active form of Vitamin D
1,25-dihydroxycholecalciferol
aka
calcitriol
Define amphipathic
A molecule with both hydrophobic and hydrophilic parts
Which vitamin converts ferric to ferrous to aid iron absorption
Vitamin C
Androgen structure C-
C19
Where is phosphate excreted from? (organ)
The kidney
patient c/o headache on the day of hysterectomy, she is known to have DM and hypothyroidism.
ABG: Ph 7.5, pco2 low, bicarb 24, normal anion gap
ABG interpretation?
Respiratory alkalosis
?due to hyperventilation
What vitamin is needed for amino acid synthesis
B6
It carries the amino acids around
Cofactor vitamin in formation of glutamic acid (an amino acid)
Vitamin K
Expected t score In 90 year old woman
-2.5
What is the main intracellular cation
K+
What is the Haldane effect?
Deoxygenation of blood increases its ability to carry co2 (shift to right)
What is the function of DNA polymerase?
DNA replication
Pregnant woman climbed high attitude and felt breathless plus parasthesia in her hands. What is the acid-base imbalance ?
Respiratory alkalosis
What is the chemical structure of BhCG?
Glycoprotein
Where in the kidney is potassium reabsorbed?
Proximal convoluted tubule AND loop of Henle
Hypercalcaemia can be managed with all of the following except:
IV saline, IV furosemide, PO pred, PO thiadize diuretics, Calcitonin
PO thiazide diuretics
Which protein is coiled in DNA?
Histones
Which of the following hormones increases the excretion of calcium in Kidney?
Calcitonin
(Low Ca –> PTH –> increased Ca)
(High Ca –> Calcitonin –> decreased Ca)
What is the name of recycling glucose/lactate without oxygen between liver and muscle (image in Q)
Cori cycle
Which enzyme found in red blood cells buffers blood CO2?
Carbonic anhydrase
When do chromatids divide and seperates to opposite poles ?
Anaphase
PMAT
Prophase / metaphase / anaphase / telophase
condense / align / separate / envelope
What electrolyte imbalance can cause paralytic ileus?
Hypokalaemia
Which electrolyte is involved in central pontine mylenosis due to fluid overload?
Na
Which lab technique is used for RNA analysis?
Northern Blotting
North = RNA
West = protein
Which one the following stage of the cell cycle immediately preceeds mitosis
G2 phase
[G0], G1, S, G2, Mitosis [PMAT]
Which nitrogen base is found only in DNA but not in RNA?
Thymine
Which enzyme is involved in the final oxidation of uric acid?
Xanthine oxidase
Most enzymes that take part in the Kreb’s cycle are located in which organelle?
mitochondria
What is the precursor of serotonin?
Tryptophan
Tryptophan –> serotonin
I am a ‘phan’ of serotonin
Rate limiting step in the synthesis of catecholamines?
Tyrosine hydroxylase
Phenylalanine –> tyrosine –> catecholamine
Which organelles do type II pneumocytes utilize for surfactant release?
Lamellar bodies
Woman climbed up the hill with her friends suddenly felt breathless plus parasthesia in her hands. What is the acid-base imbalance ?
Respiratory alkalosis
Transport of iodide into cells is associated with
Sodium
sodium / iodide co-transporter
What type of compound are histones?
Protein
Most important function of Vitamin C
Collagen formation
What percentage of anterior pituitary cells are lactotrophs?
20%
Inflammatory mediators involved in wound healing
interleukin vs VEGF??
Sudden disorientation of a women following delivery now on 35% Oxygen Abgs showed
Ph 7.2
Spo2 13.4
Spco2 8.4
Base excess -2.4
Hco3 25
Disorder
Respiratory acidosis
Where are glycolytic enzymes found?
Glycolytic enzymes are found on mitochondria
Name a co-factor for DNA synthesis
Folate
e.g. think of drugs that disrupt folate - methotrexate
Which of the following laboratory techniques is used to amplify very small amounts of DNA?
Polymerase chain reaction (PCR)
Where is most glucose reabsorbed?
PCT
What are normal ABG ranges in pregnancy?
Normal maternal
PH 7.4 - 7.47
CO2 4.1+
HCO3 20+
(roughly)
What does G6PD do?
Maintains NADPH levels, protecting RBCs against oxidative damage
What does RNA polymerase do?
Transcription
mRNA is created during the process of transcription, where an enzyme (RNA polymerase) converts the gene into primary transcript mRNA. Ribosome reads mRNA and uses amino acids to create the protein.
What is another name for omega 3
alpha linoleic acid
Which organelle is the site of lipid synthesis?
Smooth endoplasmic reticulum
mitochondria - powerhouse
SER - lipid synthesis
RER - protein synthesis
Golgi - protein modification
Lysosomes and peroxisomes - disposal
Where does the urea cycle take place?
The liver cell
Glycolysis
Anaerobic
vs aerobic products
Glycolysis
Aerobic produces ATP + pyruvate
Anaerobic produces ATP + lactate
What is on the rough endoplasmic reticulum?
Ribosomes
What is a synonym for dinoprostone
PGE2
Prostaglandin E2
What are eicosanoids (i.e. prostaglandins) derived from?
Arachidonic acid
(and other polyunsaturated fats)
What is the rate limiting step in the urea cycle?
carbamoyl phosphate synthetase (CPS)
Which organelle is the main site of protein synthesis?
Ribosomes on the RER
Which amino acid is nitric oxide derived from?
L-arginine
CRISP/Cas technology is made up of which two basic elements?
DNA+Enzyme
Which bile salts are produced by the liver
Cholic and deoxycholic acid
Which metabolic process produces the most energy (e.g. for uterine contraction)
Oxidative phosphorylation
What does left shift and right shift oxygen dissociation mean and what causes each?
Right shift - oxygen dissociation
(aka reduced O2 affinity)
with increased everything
H+, 2,3DPG, temperature
What is the name of the heat stable enzyme used in PCR?
Taq polymerase
Where is albumin synthesised?
Hepatocytes
