chapter 4- enzymes

Question 1

definition of enzymes

Answer 1

enzymes are proteins that function as biological catalysts. they catalyse or speed up the rate of chemical reaction and remain chemically unchanged at the end of the reaction.

Question 2

how is the lock-and-key hypothesis applied on enzymes and its substrates?

Answer 2

the shape of the substrate must complement the shape of the enzyme for reaction to occur, where the enzyme-substrate complex forms. the enzyme will then catalyse the reaction on its active sites where the substrate will turn into products.

Question 3

what are the factors of enzymes?

Answer 3

sensitivity to temperature and pH, specific substrate

Question 4

characteristics of enzymes

Answer 4

required in minute amounts, speed up chemical reactions and remains chemically unchanged.

Question 5

describe how the temperature affects the enzymes

Answer 5

• low temp: enzyme activity is low (effectiveness in collision between enzyme and substrate)
• optimum temp: enzyme activity is fastest
• temp beyond optimum temp: enzyme denatures and rate of reaction decreases

Question 6

describe how the pH affects the enzymes

Answer 6

• optimum pH: enzyme activity is the highest
• when pH deviates: enzyme activity decreases
• when pH are at extreme levels (pH1 and 14): enzyme denatures