Random (Metabolism)

Question 1

Inhibitors of glycolysis

Answer 1

1. Arsenate and iodoacetate - glyceraldehyde 3 phosphate dehydrogenase
2. Flouride - enolase

Question 2

Allosteric regulation of glycolysis

Answer 2

Phosphofructokinase 
Activators:
Fructose 2,6 bisphosphate, ADP, AMP
Inhibitors:
ATP, citrate, acidic pH

Question 3

PDH complex is dependent on

Answer 3

TPP
Lipoamide
Coenzyme A
FAD
NAD+

Question 4

Main precursors of gluconeogenesis

Answer 4

Pyruvate
Lactate
Glucogenic AA
Glycerol
Propionate

Question 5

Regulatory enzymes of gluconeogenesis

Answer 5

Pyruvate carboxylase
PEP-CK
Fructose 1,6 bisphosphatase
Glucose 6 phosphatase

Question 6

Type 0 glycogen storage disease

Answer 6

• liver glycogen synthase deficiency

- low glycogen stores

Question 7

Type 1 GSD

Answer 7

• Von Gierkes
• glucose 6 phosphotase deficiency
• accumulation of glycogen
• fasting hypoglycemia
• enlargement of liver
• lactic acidosis

Question 8

Type 2 GSD

Answer 8

• Pompes
• lysosomal ā(1,4) ā(1,6) glucosidase
• glycogen accumulates in lysosomes
• heart failure

Question 9

Type 3 GSD

Answer 9

• Coris
• debranching enzyme ā(1,6) glucosidase
• hepatomegaly
• symptoms vanish at puberty
• similar to von Gierkes

Question 10

Type 4 GSD

Answer 10

• Anderson’s
• branching enzyme amylo(1,4-1,6) transglycolase
• most severe
• long unbranched chains accumulate and are recognized as foreign bodies
• cardiac and liver failure before age 5

Question 11

Type 5 GSD

Answer 11

• McArdles
• muscle glycogen phosphorylase
• sufficient glycogen stores but cannot be released
• can’t tolerate strenuous activity

Question 12

Type 6 GSD

Answer 12

• Hers
• liver glycogen phosphorylase
• impaired hepatic glycogenolysis
• hepatomegaly

Question 13

Type 7 GSD

Answer 13

• Taruis
• phosphofructokinase in muscle and RBC
• hemolytic anemia
• exercise intolerance

Question 14

Chief regulatory enzyme of HMP shunt

Answer 14

Glucose 6 phosphate dehydrogenase

Question 15

G6PD inhibited by

Answer 15

NADPH

Question 16

Essential fructosuria

Answer 16

Fructokinase

Accumulation of fructose and its excretion in urine

Question 17

Hereditary fructose intolerance

Answer 17

Aldolase B

Accumulation of fructose 1 phosphate

Question 18

High intake of fructose rich food

Answer 18

Excess formation of fatty acids
Increased TAG and LDL
Decreased intracellular organic phosphate
Decreased synthesis of ATP
Increased synthesis of purines
Gout

Question 19

Why retinopathy in diabetes?

Answer 19

Accumulated glucose is converted to sorbitol with aldose reductase.
But sorbitol dehydrogenase is only present in seminal vesicles and ovaries.
So sorbitol accumulates in retina and tissues causing retinopathy

Question 20

Galactosemia

Answer 20

Galactose 1 P uridyl transferase
Excess galactose in blood
Excess is converted to galactitol
MR, jaundice, hepatomegaly, proteinuria
CONGENITAL CATARACT

Question 21

Gestational diabetes mellitus

Answer 21

When carbohydrate intolerance is noticed for the first time during pregnancy

• can cause neonatal mortality
• fetus secrets more insulin leading to increased birth weight of fetus

Question 22

Type 1 DM

Answer 22

• Decreased insulin production
• early onset
• T cells attack insulin secreting cells of islets of langerhans

Question 23

Type 2 DM

Answer 23

• decreased response to insulin

- late onset

Question 24

Metabolic syndrome

Answer 24

Abdominal obesity + hypertryglyceridemia + high BP + high plasma glucose

• Insulin resistance syndrome
• increased risk of CAD and type 2 DM

Question 25

Kimmelstiel Wilson syndrome

Answer 25

- Complication of DM - Nephrosclerosis - proteinuria - renal failure

Question 26

Mucopolysaccharidoses

Answer 26

Intralysosomal accumulation of GAG in tissues - coarse facial features - thick skin - corneal opacity - MR

Question 27

Tay Sachs disease

Answer 27

- Failure of degradation of gangliosides - Low Hexosaminidase A - cherry red spot in macula

Question 28

Hyperammonemia

Answer 28

- feature of liver failure - also called portal systemic encephalopathy - toxins produced in intestines bypass liver - conc. in blood increases - CNS dysfunction - jaundice, hepatomegaly

Question 29

Lactose intolerance

Answer 29

- deficiency of lactase - lactose accumulates in gut - diarrhea and flatulence - secondary - lactase activity decreases as age advances - treated with curd or yeast as they are rich in lactase

Question 30

Glucose galactose malabsorption

Answer 30

- Defective SGluT-1 - transporter of glucose in intestine - secondary active transport

Question 31

Congenital renal glycosuria

Answer 31

- defective SGluT-2 - transporter of glucose in kidneys - secondary active transport

Question 32

Oral rehydration solution

Answer 32

- treatment for diarrhea - contains glucose and sodium - allows absorption of Na to replenish NaCl levels and glucose to provide energy

Question 33

Pasteur effect

Answer 33

The inhibitory effect of oxygen on glycolysis

Question 34

Warburg hypothesis

Answer 34

- cancer cells utilise energy from glycolysis - they require lesser oxygen - inhibition of glycolysis depletes ATP in cancer cells leading to cell death. - warburg effect and hypoxia are frequently seen in human cancers

Question 35

Deficiency of glycolytic enzymes

Answer 35

- mainly pyruvate kinase and hexokinase - hemolytic anaemia - hexokinase deficient RBC have low 2,3 BPG and high O2 affinity - PK deficient RBC have high 2,3 BPG and low O2 affinity

Question 36

Malignant hyperthermia

Answer 36

- occurs when halothane is given as anaesthetic - calcium release channel is defective - inappropriate release of Ca from sarcoplasmic reticulum - uncontrolled heat generation - ATP depletion - Lactic acidosis - CPK elevated

Question 37

Essential pentosuria

Answer 37

-one of members of Garrods triad -decreased xylitol dehydrogenase and xylitol reductase -L glucose is not converted to D glucose and is excreted in urine -benedicts test +ve -