Enzymes

Question 1

What is an enzyme?

Answer 1

Biological Catalyst.

Question 2

What type of proteins are enzymes?

Answer 2

Globular

Question 3

What type of reactions are catalysed by enzymes?

Answer 3

Anabolic and Catabolic

Building up and Breaking Down

Question 4

What is activation energy?

Answer 4

The energy required for most reactions to start

Question 5

What is the lock and key hypothesis?

Answer 5

Active site is a specific shape only for the specific substrate molecule. When the substrate is bound it’s an ESC. When the products form it’s an EPC.

Ideal that enzyme active site is already the PERFECT SHAPE.

Question 6

What is the induced fit hypothesis?

Answer 6

The active site of the enzyme changes shape slightly as the substrate enters. Initial interaction between enzyme abs substrate relatively weak but these interaction cause changes in tertiary structure strengthening binding and putting extra strain on molecule. Lower AE.

Question 7

What are intracellular enzymes?

Answer 7

Enzymes that act within cells

Question 8

What enzyme catalyses the breakdown of hydrogen peroxide into oxygen and water?

Answer 8

Catalase.

Question 9

Example of extracellular enzymes?

Answer 9

Amylase and Trypsin

Question 10

Explain the digestion of starch in the body?

Answer 10

Amylase breaks down starch polymers into maltose. Amylase if produced by salivary cells and the pancreas. Released in saliva in mouth and pancreatic juice into small intestine.

Maltose is then broken down into glucose by the enzyme maltase which is present in the small intestine.
Glucose is then absorbed into cells lining the digestive system and subsequently absorbed into blood stream.

Question 11

What enzyme is responsible for the breakdown of proteins in the digestion system?

Answer 11

Trypsin ( a form of protease)

Question 12

What 3 factors impact Enzyme Activity?

Answer 12

pH

Temperature

Concentration of Substrate.

Question 13

What happens to the active site when an enzyme is denatured?

Answer 13

The active site changes shape as bonds that determine tertiary structure have been broken. As a result, the active site is no longer complementary to the substrate.

Question 14

How does pH impact enzyme activity?

Answer 14

Hydrogen bonds and ionic bonds between amino acid R groups hold proteins in their precise 3D shape.

Question 15

What is a coenzyme?

Answer 15

Cofactors made up from An organic molecule

Question 16

What is a cofactor?

Answer 16

A non-protein helper component, may transfer atoms or groups from one reaction to another in a multi step pathway.

Question 17

What happens to enzymes at a low pH?

Answer 17

More hydrogen ions are present, therefore the R groups interact less with eachother. This leads to bonds breaking and the shape of the enzyme changing.
No longer complementary and cannot catalyse the reaction.