Chapter 5

Question 1

catalyst

Answer 1

a substance that increases the rate of a chemical reaction and is not changed by the reaction

Question 2

enzymes

Answer 2

proteins that function as biological catalysts

Question 3

Describe why enzymes are important in all living organisms

Answer 3

Without enzymes, some of our essential bodily functions would not be quick enough to keep us alive. This includes processes such as respiration and digestion.

Question 4

Investigate and describe the effect of changes in temperature and pH on enzyme activity

Answer 4

1

Question 5

Explain enzyme action with reference to the active site, enzyme-substrate complex, substrate and product

Answer 5

Enzymes catalyse reactions in which substrates are converted into products. The enzyme and the substrate have a shape that is complementary so they fit each other at the active site. This also makes it so the enzyme can only catalyse one particular substrate. Once they fit together in the active site, the reaction can take place. When the reaction is over the product/s leave the enzyme and another substrate comes in.

Question 6

Explain the specificity of enzymes in terms of the complementary shape and fit of the active site with the substrate

Answer 6

Enzymes have a specific shape of the active site which complements its substrate. This makes it so the enzyme can only change a certain substrate, not every substrate.

Question 7

Explain the effect of changes in temperature on enzyme activity in terms of kinetic energy, shape and fit, frequency of effective collisions and denaturation

Answer 7

if the temperature increases, the enzyme would gain more kinetic energy and have more effective collisions. This means more of the product would be produced. However if it is too hot, the shape and active site could be disfigured making the enzyme unable to do its job. eventually, this can cause the enzyme to denature.

Question 8

Explain the effect of changes in pH on enzyme activity in terms of shape and fit and denaturation

Answer 8

Too high or low of a pH for an enzyme beyond its optimum can make it so the shape and active site of an enzyme can become disfigured making it unable to connect with the substrate. Eventually, the enzyme will denature.