Chapter 5: Enzyme

Question 1

catabolism

Answer 1

• breaking down complex compound into simpler compound

- release energy

Question 2

anabolism

Answer 2

• sythesing complex compound from simple compound

- absorb energy

Question 3

general characteristics of enzyme

Answer 3

• act rapidly
• act as biological catalyst to speed up biochemical process
• required small quantities and reusable
• reaction catalyst by enzyme are reversible
• some enzyme reaction need to be aided by cofactor
• some enzyme reaction could be slow down or stopped by inhibitor
• the structure of enzyme remain unchanged after reaction
• specific

Question 4

how extracellular enzyme produced

Answer 4

1. protein is synthesised in ribosome
2. protein synthesised by ribosome enter the lumen of rough endoplasmic reticulum and transported along it
3. when it reaches the end of RER, the membrane buds off and form transport vesicles
4. the transport vesicle move towards golgi apparatus and fuses with it
5. Golgi apparatus process, modify and package the protein into enzyme
6. the enzyme is then secreted in secretory vesicles and the end of Golgi apparatus
7. secretory vesicles move towards plasma membrane and fuses with it
8. enzyme is secreted extracellularly

Question 5

what is activation energy

Answer 5

• the energy required to break the bond in substrate before the reaction occur

Question 6

how does enzyme denatured at extreme temperature

Answer 6

• the chemical bonds in the enzyme molecules break at extreme temperature (60C)
• cannot retain the 3-dimensional form
• shape of active site changed
• substrate does not complement the active site of the enzyme anymore

Question 7

effect of pH value to enzyme

Answer 7

• changes in pH value change the charge (H+ ions) on the active site of enzyme and the substrate surface
• thus, enzyme-substrate complex cannot formed
• when the pH return its optimum level, the charges will be restore
• extreme changes of pH value will break the structural chemistry bond
• active site of enzyme changed
• enzyme denatured

Question 8

immobilized enzyme technology

Answer 8

• enzyme combine with inert and insoluble substances
• to increase the resistance of enzyme towards changed in factors (temperature and pH)
• enzyme will remain in the same position throughout the catalytic reaction
• can be separated easily from its product