Digestive Enzymes

Question 1

Carbohydrates

Answer 1

Nutrient: carbohydrates

Name of enzyme which breaks the nutrient down: Carbohydrase/amylase

In which part of the digestive system does the enzyme work?: The part of the digestive system that the enzymes works in is the mouth and saliva in the mouth

What are the products of the reaction (what are the nutrients broken down into): The products of the reaction are that starch is broken down into sugar

Question 2

Proteins

Answer 2

Nutrient: protein

Name of enzyme which breaks the nutrient down: Protease

In which part of the digestive system does the enzyme work?: The part of the digestive system that the enzymes works in is the stomach

What are the products of the reaction (what are the nutrients broken down into): The products of the reaction are that protein is broken down into amino acids

Question 3

Lipids (fats)

Answer 3

Nutrient: Lipids (fats)

Name of enzyme which breaks the nutrient down: Lipase

In which part of the digestive system does the enzyme work?: The part of the digestive system that the enzymes works in is the small intestine

What are the products of the reaction (what are the nutrients broken down into): The products of the reaction are that lipids are broken down into glycerol and fatty acid chains

Question 4

Enzymes

Answer 4

Enzymes are special proteins involved in ‘metabolism’ (reactions in body)-they help to speed up reactions (they are biological catalysts)

Digestive enzymes break food into small soluble molecules that can be absorbed from the small intestine into the bloodstream.

Question 5

How do enzymes work?

Answer 5

This is known as the “lock and key” model.

The substrate fits into the active site, which is “complementary” in shape.

This explains why different enzymes are needed for different substrates.

Question 6

Temperature and Enzyme Activity

Answer 6

What do we mean when talk about ‘optimum temperature’?

Optimum temperature is the highest point on the graph where the reaction is the fastest/highest.

Question 7

pH and Enzyme Activity

Answer 7

Why does pH affect the way an enzyme works?
The pH affects the way an enzyme works is that active site changes shape because some work under alkaline conditions and some work under acids depending on the enzyme. At the optimum pH, the enzyme (active site) will be the right shape for the substrate. Away from the optimum pH, the enzyme is DENATURED.