Topic 2

Question 1

what are enzymes?

Answer 1

• Enzymes are catalysts for the chemical reaction in living cells
• Enzymes are made up of protein
• Enzymes made up of RNA are called ribozyme
• May exist as a multi enzyme complex
• Enzymes do not consume themselves or undergo permanent change during the reaction
• Thus enzymes can be used repeatedly
• Enzymes are globular protein that has one or more active sites for the substrate to bind to
• When the substrate binds to the active site of the globular protein, it forms a enzyme-substrate complex, the enzyme changes its shape slightly to ensure that the substrate is blinded well to its active site which makes it optimum for catalysis (induced fit)
• By bringing the two substrates together at the correct orientation or stressing the chemical bonds of the substrate it decreases the activation energy needed for the two substrates to bond together, speeding up reaction time

Question 2

An example of this

Answer 2

Activation site of enzyme lysozyme fits shape of substrate, a peptidoglycan that makes up bacterial cell wall

Question 3

what is multienzyme complex and it’s benefits

Answer 3

Multi enzyme complex are several enzymes that catalyse different steps in the sequence of a reaction and are associated to one another in non covalently bonded assemblies

Examples:
- Bacterial pyruvate dehydrogenase multi enzyme complex

• fatty acid synthetase complex

Have significant advantages in catalytic efficiency
- Reactant wouldn’t diffuse away between each step of catalytic reaction

• Limit unwanted reactions of intermediate reactant
• All reactions can be controlled as a unit

Question 4

What are cofactors

Answer 4

Cofactors are found in the active site of the enzyme that participates directly in catalysis

Makes bonds less stable and easier to break

Example metal ions: Zinc, iron, molybdenum, manganese

Question 5

what are coenzymes

Answer 5

do enzymes are non protein organic molecule that acts as a co factor (coenzyme)

• Vitamin B6, B12