Enzymes

Question 1

What are the biological functions of enzymes?

Answer 1

Part of metabolic pathways
Signal transduction and cell regulation - kinases, phophatases
Digestion
Movement - myosin
Energy ruction
Drug metabolism - monooxygenases

Question 2

Role of enzymes in diseases?

Answer 2

Can be used drug targets for metabolic disorders and infections
Diagnostic mares in acute and chronic conditions
Cause of inborn errors - deficiency or recused activity

Question 3

Examples of enzymes as drug targets

Answer 3

Angiotensin-converting-enzyme - treatment of hypertension
3-hydroxyl-3-methyl -glutaryl-CoA reuctase- lowering LDL, cholesterol
D-alanyl-D-alanine carboxypeptidase - bacterial infection

Question 4

Examples of enzymes as diagnostic markers

Answer 4

Creative phosphokinase - myocardial infarction
Aspartame amino transferase - liver disease

Question 5

Enzymes in inborn errors of metabolism

Answer 5

Phenylalanine hydroxylase - phenylketonuria
Clotting factor VIII - haemophilia

Question 6

What is the michealis-menten equation for enzyme reactions?

Answer 6

Goal: v=f([S])

v = Vmax X [S]/[S]+Km

Question 7

What is Km?

Answer 7

Measure for stability of enzyme-substrate complex
Large Km = low substrate-enzyme affinity
Small Km = high substrate-enzyme affinity

Question 8

What is AST?

Answer 8

Aspartate amino transferase
For diagnosing liver disease
Tissue source - heart, skeletal muscle, liver

Question 9

What is ALT?

Answer 9

Alanine amino transferase
For diagnosing liver disease e.g. hepatitis
Tissue source - liver

Question 10

What is amylase used to diagnose?

Answer 10

Acute pancreatitis and biliary obstruction
Tissue source - pancreas, salivary glands

Question 11

What is CPK ?

Answer 11

Creatinine phosphokinase
Used to diagnose muscular dystrophy, myocardial infarction
Tissue source - skeletal muscle, heart

Question 12

What is GGT?

Answer 12

Gamma glutamyl transferase
Used to diagnose hepatitis, alcohol excess
Tissue source - liver

Question 13

What is LDH?

Answer 13

Lactate dehydrogenase
Diagnostic use - lymphoma, hepatitis, myocardial infarction
Tissue source - heart, liver, erythrocytes

Question 14

What is lipase used to diagnose?

Answer 14

Acute pancreatitis, biliary obstruction
Tissue course - pancreas

Question 15

What is alkaline phosphatase?

Answer 15

Diagnostic use - bone disorder, bone tumour
Tissue source - osteoblasts

Question 16

What is acid phosphatase?

Answer 16

Diagnostic use - prostate cancer
Tissue course - prostate