Biochemistry (Enzymes)

Question 1

Factors that affect enzyme activity

Answer 1

temperature: as temperature increases, substrate molecules and enzymes move faster which leads to more frequent collision, which gives more chemical reactions. once the enzyme goes over its optimum temperature is starts to denature and its activity falls

pH: as pH increases it becomes less reactive. all enzymes have their own optimum pH, and at pHs that are very different pH, the enzyme starts to denature and decreases in activity.

substrate concentration: as substrate concentration increase, rate of reaction increase. when point of saturation is reached, increased concentration does not affect the rate. when substrate concentration increases, collision between enzymes and substrate molecules is more frequent which increases enzyme activity. increasing substrate activity beyond the point of saturation makes no difference to rate of reaction because enzymes have reached their maximum work rate.

Question 2

immobilized enzymes is

Answer 2

to restrict enzyme mobility in a fixed space.

Question 3

how is immobilized enzymes useful to make money

Answer 3

lactose free milk: enzyme lactase is used to break down the sugar lactose, which is found in milk. this produces glucose and galactose.

high fructose corn syrup production: glucose isomerase is used to convert glucose into fructose. this makes food and drink taste sweeter.

clear fruit juice: natural fruit juice contain pectin which makes them cloudy. pectinase will break down pectin so that the juice will turn clear.

biological washing powder: biological washing powder contains proteases, amylases and lipases. more effective in breaking down food stains, work well at lower temperatures.

Question 4

lactose-free milk

Answer 4

milk can be treated with the enzyme lactase in order to break down the sugar lactose. this creates lactose-free milk.

Question 5

advantages of lactose-free milk production

Answer 5

• allows lactose intolerant people to consume milk product
• makes milk taste sweeter since glucose and galactose tastes sweeter than lactose.
• glucose and galactose are more soluble, gives milk smoother texture and reduces crystallization in ice cream
• bacteria can ferment glucose and galactose more easily. reduces time taken to manufacture cheese