Ch.5 Enzymes Flashcards
1
Q
Define enzyme
A
Biological catalyst that can increase the rate of reaction of a chemical reaction, without being chemically changed or used up by the reaction.
2
Q
Enzymes are made out of
A
Proteins
3
Q
Amylase
A
Digests starch into maltose
4
Q
Maltase
A
Digests maltose into glucose
5
Q
Protease
A
Digests proteins into amino acids
6
Q
Lipase
A
Digests fats into fatty acids and glycerol
7
Q
Enzymes - about its specificity
A
Complementary shape of a substrate that can fit into the active site of an enzyme
8
Q
Carbohydrases
A
Digests carbohydrates
9
Q
Substrate
A
Substance which the enzyme acts on
10
Q
Active site
A
Depression on the surface
11
Q
Characteristics of enzymes
A
- Catalyse reversible reactions
- Speed up rate of chemical reactions
- Remain unchanged at the end of the chemical reaction
- A small amount of enzyme can catalyse a large number of chemical reactions eg washing powder and a large load of clothes
12
Q
Factors affecting enzymes - pH
A
- Enzyme that works best in acidic solutions: pepsin in the stomach
- Enzyme that works best in alkaline solutions: intestinal enzymes
- Maximum activity for an enzyme = optimum pH
- Denatured = Substrate no longer able to fit into an active site. This is irreversible
12
Q
Factors affecting enzymes - pH
A
- Enzyme that works best in acidic solutions: pepsin in the stomach
- Enzyme that works best in alkaline solutions: intestinal enzymes
- Maximum activity for an enzyme = optimum pH
- Denatured = Substrate no longer able to fit into an active site. This is irreversible
13
Q
Facts affecting enzymes - Temperature
A
- For most enzymes, the optimum temperature is about 40-45 degrees Celsius (although everything else says 37 degrees)
- Lower temp - enzyme inactive
- Higher temp - enzyme denatured as there is a rapid decrease in the rate of enzyme reaction. High kinetic energy breaks down enzyme bonds and enzyme loses shape and active site.
- Most enzymes are denatured above 60 degrees Celsius
