Biochemistry Flashcards
What is the main intracellular Cation?
Potassium
Which organelle is responsible for protein folding and is studded with ribosomes?
Rough endoplasmic reticulum
Which organelles is responsible for holding mRNA
for translation into protein?
Ribosomes
What is the 2nd common enzymatic deficiency after 21-OH CAH (21 hydroxylase)?
11-Beta Hydroxylase
location of fatty acid synthesis within the cell
Cytosol
Which eicosanoids increase before mensteruation?
Prostaglandin F2-alpha
which enzyme in the renal tubular cells is responsible for synthesis of ammonia?
glutaminase
from what parent compound are most eicosanoids derived
Arachidonic acid
NO is synthesised from which aminoacid
L-arginine
Progesteron receptor is of which types of receptors
Nuclear transcription receptor
No of carbon in estrogen is
18
Most enzymes that takes part in krebs cycle is located in
Mitochondria
What chemical process utilizes pyruvate to form ATP
Kreb’s Cycle
the overall product of glycolysis
2 molecules of Pyruvate
4 ATP
2 NADH
which enzyme is involved in rate-limiting step of glycolysis pathway
phosphpfructokinase
Enumerate ketone bodies
- Acetone (can’t be metabolised)
-Acetoacetate
-Beta hydroxybutyrate
From what Nitric Oxide biosynthesized
L-arginine
Catalyst enzyme in Nitric Oxide biosynthesis
Nitric Oxide Synthase NOS
Effects of Nitric Oxide
- Vasodilation
- Modulation of hair cycle
- Penile Erection
Types of Nitric Oxide
- Endotherlial (eNOS)
- Inflammatory (iNOS)
- Brain
Action of Endothelial NO (eNOS)
-act on vascular smooth muscle
-expressed by synctiotrophoblast
Secretion of Inflammatory NO (iNOS)
by bacterial cell wall and neutrophils following activation by tumor necrosis factor TNF or Interferon-Y
cAMP derived from what and by which enzyme
ATP by adenylate cyclase
cAMP actions mediated by
Protein Kinase A
Action of cAMP on different cells
in liver: stimulate glycogen breakdown
in adipocytes: stimulate the production of fatty acids
in ovarian cells they induce the formation of estradiol and progesterone.
The synthesis of cGMP is catalysed by
guanylate cyclase
Lactate is converted to glucose via
Cori’s cycle.
The brain has an absolute requirement for glucose:
• During normal food intake: 100g/day.
• During starvation: 25g/day
ATP production during aerobic metabolism
- Glycolysis (2 ATP)
- Krebs Cycle (2 ATP)
- Electron Transport Chain (34 ATP)
The liberation of fatty acids from the TAG molecule is catalysed by the enzyme
hormone sensitive lipase (HSL).
Types of Ketone bodies
Acetone, acetoacetate & β-hydroxybutyrate
Initial helical folding of Aminoacids held together by
Hydrogen bonding
Amino acid chain folds back on itself to form 3D structure held by
disulphide bond
hich enzyme in the renal tubular cells are responsible for
production of ammonia?
Glutaminase
Essential AminoAcids
PVT. TIM HALL
Phenylalanine
Valine
Threonine
Tryptophan
Isoleucin
Methionine
Histidine
Leucine
Lysine
What is the structure of fetal haemoglobin?
Two alpha chains and two gamma chains (α2γ2)
What is the function of the enzyme glucose 6 phosphatase in
carbohydrate metabolism?
Converts glucose 6 phosphate to glucose
In times of starvation which ketone body can be utilized by the heart for energy?
Beta-hydroxybutyric acid
Where in the body are ketone bodies produced during times of
starvation?
Liver
Main organelle for oxidizing fatty acid?
Mitochondria
what describes the function of low-density lipoproteins?
Transport of cholesterol from the liver to tissues around the body
Which process occurs in the mitochondria where uses electrons
transport to generate adenosine triphosphate (ATP)
Oxidative phosphorylation
In which part of the cell does glycolysis take place?
Cytosol
Which intracellular organelle is concerned with processes, packages and transports proteins out of the cell?
Golgi apparatus
Tryptophan is precursor of
Seritonin
Arginine is precursor of
Nitric Oxide
Tyrosine is precursor of
L-Dopa –> dopamine and noradrenaline
Number of carbons in Oestrogen?
18
What type of hormone is prostaglandin
Paracrine
Which essential fatty acids not found in OMEGA 3 and should be taken from dietary intake ?
alpha-Linoleic acid
What is the site where Urea cycle occurs ?
Liver
What is the site of production of Ammonia?
Kidney
Cristae are present in ?
Mitochondria
(different from cisternae that is found in rER and Golgi apparatus)
What cellular organelle is especially abundant in cells that synthesize antibodies?
rER
Glucagon works by which of the following mechanisms to reverse the hypoglycemia?
Gluconeogenesis
In anaerobic metabolism of glucose, if persistent with loss of oxygen, condition goes in the process of?
Cori’s Cycle
“During anaerobic conditions(loss of O2)the body find ways to produce energy. Glucose is converted to Lactate in the muscle then converted back to glucose in the liver.”
What is the overall product of the glycolysis pathway?
Pyruvate
What is the site of production of Thromboxane A2 ?
Platelets
What is DKA
Complication arises for individuals with diabetes, in whom impaired control of Hormone Sensitive Lipase means that the plasma concentration and rates of oxidation of fatty acids persist at high levels even in the fed state.
The loss of control of HSL leads to the uncontrolled production of ketone bodies.
What is phenylketonuria?
The disorder is characterised by the absence or greatly diminished activity of the enzyme phenylalanine hydroxylase, with the result that the common acid, phenylalanine cannot be metabolised.
phenylketonuria is readily detected by means of
the Guthrie test, which is carried out 6–14 days after birth.
Excessive dose of Oxytocin in obstetrics causes
Water Retention
Iatrogenic Hyponatremia
Central Diabetis insipid characterized by
Decreased ADH causing
- Polyuria
- Polydipsia
What is nephrogenic DI
Resistant Kidney to ADH, Observed in:
1. CRF (commonly)
2. X-linked disease result from AVP-V2 receptor failure (rarely)
3. Autosomal recessive disease d.t. mutation of aquaporin-2 (more rare)
Secretory cells of GH form Anterior pituitary
Somatotrophs (40-50% of ant. pituitary)
Secretory cells of Prolactin form Anterior pituitary
Lactotrophs 10-15% (Increasing in pregnancy – may reach 50% by term)
Secretory cells of ACTH form Anterior pituitary
Corticotrophs (15-20%)
Secretory cells of FSH & LH from Anterior pituitary
Gonadotrophs (10-15%)
FSH & LH receptors
G protein- linked proteins.
Prolactin is made up of how many Amino acids
199 AA
Action of hypothalamus on Prolactin
Inhibitory action
Thus, damage to the hypothalamic control causes increased PRL levels
The main neuro-hormone inhibiting PRL secretion
Dopamine
also somatostatin has inhibitory action
PRL has effects on the hypothalamic–pituitary–gonadal axis
it can inhibit pulsatile secretion of GnRH from the hypothalamus.
Excess prolactin may cause infertility due to the inhibitory actions of prolactin on GnRH secretion.
the most common hormone-secreting pituitary tumours
prolactinoma
What is Sheehan syndrome
Severe haemorrhage, shock or hypotension during or before parturition may lead to postpartum pituitary necrosis or Sheehan syndrome. This results in partial or complete hypopituitarism
What is the chemical structure of GnRH ?
Decapeptide
Which hormone promotes cartilage mitosis in epiphyseal plate of long bones?
Growth Hormone
What is the most abundant carbohydrate in the breast milk?
Lactose
Prognathism and macroglossia are features of
Acromegaly
What is the most common cause of acromegaly?
Pituitary adenoma
Which hormones are required for alveolar morphogenesis during
pregnancy ?
Progesterone, Prolactin and hPL
Which hormone is responsible for contraction of myo-epithelial cells in lactation?
Oxytocin
Sheehan syndrome affects?
Ant. pituitary
The rate of growth hormone secretion follows a circadian rhythm. When is the highest peak of growth hormone release?
Early sleep
(If deep sleep is an option then it’s right)
Vasopressin act on increasing water re-absorption at ?
Collecting ducts
Where is prolactin produced that is not under dopaminergic control?
maternal decidua
Which hormone causes rupture of Graffian follicle ?
LH
Which signaling molecule that stimulate the renin-angiotensin system to regulate the sodium concentration?
Norepinephren
Vitamin causing pellagra
Niacin
Major buffer in urine
Phosphate
