Biochemistry

Question 1

What happens to arterial PCO2 in normal pregnancy?
Normal ABG in non-pregnant adult?

Answer 1

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

Question 2

At what phase of eukaryotic cell division can the cell go into a quiescent stage?

Answer 2

G0

[G0] <-> G1 - S - G2 - Mitosis (PMAT
condense/align/separate/envelope) –>

Question 3

Dexa scan result ranges
normal
osteopenia
osteoporosis

Answer 3

normal > -1 (eg -0.5)
Osteopenia -1 to -2.5
Osteoporosis < - 2.5 (e.g. -2.9)

Question 4

Oestrogens in order from least to most potent

Answer 4

Estriol –> Estrone –>Estradiol

Question 5

What process occurs exclusively in the mitochondria?

Answer 5

Oxidative phosphorylation

Question 6

82% of Estradiol binds to what in the blood?

Answer 6

Albumin

Question 7

What mechanism is required for myometrial contraction?

Answer 7

Elecrtron transport chain

Question 8

What does the Golgi apparatus do?

Answer 8

Package proteins into membrane bound vesicles

Question 9

At what stage in the cell cycle is mitosis arrested if there is a chromosomal abnormality?

Answer 9

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.’

Question 10

Where in the kidney is the majority of bicarbonate reabsorbed

Answer 10

PCT

Question 11

What cell type secretes calcitonin?

Answer 11

C-cells of thyroid gland

Question 12

What is the most abundant oestrogen in pregnancy?

Answer 12

Estriol

Question 13

List the the estogens in the order of their activity on the vaginal mucosa

Answer 13

Estradiol-estrone-estriol

This is the same as strongest to weakest

Question 14

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?

Answer 14

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)

Question 15

What is the Z score

Answer 15

A Z-score compares bone density to the average values for a person of the same age and gender

Question 16

A phase of the cell cycle where DNA replication occurs / controls mutation of genes:

Answer 16

S phase

Question 17

most important anion in urine

Answer 17

Chloride

Same as in ECF

Question 18

Active form of Vitamin D

Answer 18

1,25-dihydroxycholecalciferol
aka
calcitriol

Question 19

Define amphipathic

Answer 19

A molecule with both hydrophobic and hydrophilic parts

Question 20

Which vitamin converts ferric to ferrous to aid iron absorption

Answer 20

Vitamin C

Question 21

Androgen structure C-

Answer 21

C19

Question 22

Where is phosphate excreted from? (organ)

Answer 22

The kidney

Question 23

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?

Answer 23

Respiratory alkalosis
?due to hyperventilation

Question 24

What vitamin is needed for amino acid synthesis

Answer 24

B6
It carries the amino acids around

Question 25

Cofactor vitamin in formation of glutamic acid (an amino acid)

Answer 25

Vitamin K

Question 26

Expected t score In 90 year old woman

Answer 26

-2.5

Question 27

What is the main intracellular cation

Answer 27

K+

Question 28

What is the Haldane effect?

Answer 28

Deoxygenation of blood increases its ability to carry co2 (shift to right)

Question 29

What is the function of DNA polymerase?

Answer 29

DNA replication

Question 30

Pregnant woman climbed high attitude and felt breathless plus parasthesia in her hands. What is the acid-base imbalance ?

Answer 30

Respiratory alkalosis

Question 31

What is the chemical structure of BhCG?

Answer 31

Glycoprotein

Question 32

Where in the kidney is potassium reabsorbed?

Answer 32

Proximal convoluted tubule AND loop of Henle

Question 33

Hypercalcaemia can be managed with all of the following except: IV saline, IV furosemide, PO pred, PO thiadize diuretics, Calcitonin

Answer 33

PO thiazide diuretics

Question 34

Which protein is coiled in DNA?

Answer 34

Histones

Question 35

Which of the following hormones increases the excretion of calcium in Kidney?

Answer 35

Calcitonin (Low Ca --> PTH --> increased Ca) (High Ca --> Calcitonin --> decreased Ca)

Question 36

What is the name of recycling glucose/lactate without oxygen between liver and muscle (image in Q)

Answer 36

Cori cycle

Question 37

Which enzyme found in red blood cells buffers blood CO2?

Answer 37

Carbonic anhydrase

Question 38

When do chromatids divide and seperates to opposite poles ?

Answer 38

Anaphase PMAT Prophase / metaphase / anaphase / telophase condense / align / separate / envelope

Question 39

What electrolyte imbalance can cause paralytic ileus?

Answer 39

Hypokalaemia

Question 40

Which electrolyte is involved in central pontine mylenosis due to fluid overload?

Answer 40

Na

Question 41

Which lab technique is used for RNA analysis?

Answer 41

Northern Blotting North = RNA West = protein

Question 42

Which one the following stage of the cell cycle immediately preceeds mitosis

Answer 42

G2 phase [G0], G1, S, G2, Mitosis [PMAT]

Question 43

Which nitrogen base is found only in DNA but not in RNA?

Answer 43

Thymine

Question 44

Which enzyme is involved in the final oxidation of uric acid?

Answer 44

Xanthine oxidase

Question 45

Most enzymes that take part in the Kreb’s cycle are located in which organelle?

Answer 45

mitochondria

Question 46

What is the precursor of serotonin?

Answer 46

Tryptophan Tryptophan --> serotonin I am a 'phan' of serotonin

Question 47

Rate limiting step in the synthesis of catecholamines?

Answer 47

Tyrosine hydroxylase Phenylalanine --> tyrosine --> catecholamine

Question 48

Which organelles do type II pneumocytes utilize for surfactant release?

Answer 48

Lamellar bodies

Question 49

Woman climbed up the hill with her friends suddenly felt breathless plus parasthesia in her hands. What is the acid-base imbalance ?

Answer 49

Respiratory alkalosis

Question 50

Transport of iodide into cells is associated with

Answer 50

Sodium sodium / iodide co-transporter

Question 51

What type of compound are histones?

Answer 51

Protein

Question 52

Most important function of Vitamin C

Answer 52

Collagen formation

Question 53

What percentage of anterior pituitary cells are lactotrophs?

Answer 53

20%

Question 54

Inflammatory mediators involved in wound healing

Answer 54

interleukin vs VEGF??

Question 55

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

Answer 55

Respiratory acidosis

Question 56

Where are glycolytic enzymes found?

Answer 56

Glycolytic enzymes are found on mitochondria

Question 57

Name a co-factor for DNA synthesis

Answer 57

Folate e.g. think of drugs that disrupt folate - methotrexate

Question 58

Which of the following laboratory techniques is used to amplify very small amounts of DNA?

Answer 58

Polymerase chain reaction (PCR)

Question 59

Where is most glucose reabsorbed?

Answer 59

PCT

Question 60

What are normal ABG ranges in pregnancy?

Answer 60

Normal maternal PH 7.4 - 7.47 CO2 4.1+ HCO3 20+ (roughly)

Question 61

What does G6PD do?

Answer 61

Maintains NADPH levels, protecting RBCs against oxidative damage

Question 62

What does RNA polymerase do?

Answer 62

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.

Question 63

What is another name for omega 3

Answer 63

alpha linoleic acid

Question 64

Which organelle is the site of lipid synthesis?

Answer 64

Smooth endoplasmic reticulum mitochondria - powerhouse SER - lipid synthesis RER - protein synthesis Golgi - protein modification Lysosomes and peroxisomes - disposal

Question 65

Where does the urea cycle take place?

Answer 65

The liver cell

Question 66

Glycolysis Anaerobic vs aerobic products

Answer 66

Glycolysis Aerobic produces ATP + pyruvate Anaerobic produces ATP + lactate

Question 67

What is on the rough endoplasmic reticulum?

Answer 67

Ribosomes

Question 68

What is a synonym for dinoprostone

Answer 68

PGE2 Prostaglandin E2

Question 69

What are eicosanoids (i.e. prostaglandins) derived from?

Answer 69

Arachidonic acid (and other polyunsaturated fats)

Question 70

What is the rate limiting step in the urea cycle?

Answer 70

carbamoyl phosphate synthetase (CPS)

Question 71

Which organelle is the main site of protein synthesis?

Answer 71

Ribosomes on the RER

Question 72

Which amino acid is nitric oxide derived from?

Answer 72

L-arginine

Question 73

CRISP/Cas technology is made up of which two basic elements?

Answer 73

DNA+Enzyme

Question 74

Which bile salts are produced by the liver

Answer 74

Cholic and deoxycholic acid

Question 75

Which metabolic process produces the most energy (e.g. for uterine contraction)

Answer 75

Oxidative phosphorylation

Question 76

What does left shift and right shift oxygen dissociation mean and what causes each?

Answer 76

Right shift - oxygen dissociation (aka reduced O2 affinity) with increased everything H+, 2,3DPG, temperature

Question 77

What is the name of the heat stable enzyme used in PCR?

Answer 77

Taq polymerase

Question 78

Where is albumin synthesised?

Answer 78

Hepatocytes