Biology Enzymes And Digestion

Front 1

What are the two stages of digestion?

Back 1

Physical breakdown- teeth, stomach muscles
Chemical breakdown- enzymes

Front 2

What is hydrolysis?

Back 2

Splitting up molecules by adding water to the chemical bonds that hold them together

Front 3

What enzymes break down carbohydrate, lipids, proteins?

Back 3

Carbohydrases
Lipases
Proteases

Front 4

What is a monosaccharide?

Back 4

The monomers (1 chain organic molecules) of carbohydrates

Front 5

Sucrose=

Back 5

Glucose + fructose

Front 6

Maltose=

Back 6

Glucose + glucose

Front 7

Lactose=

Back 7

Glucose and galactose

Front 8

What is a glycosidic bond?

Back 8

The bond that bonds two monomers together (eg. Glucose + glucose)

Front 9

What is a condensation reaction?

Back 9

Making bonds between two monosaccharides by removing H2O

Front 10

Give example of Carbohydrases and describe what they do and where the source is

Back 10

Salivary amalyse
Break down carbohydrates into sugars
Salivary glands

Front 11

Give example of Lipases, what they do and where the source is

Back 11

Pancreatic lipase
Break down fats into fatty acids and glycerol
Pancreas

Front 12

Give example of proteases, what they do and where is the source

Back 12

Pepsin
Break down proteins into amino acids
Gastric band in stomach wall

Front 13

Name of enzyme that breaks down lactose

Back 13

Lactase

Front 14

Describe and explain symptoms of lactose intolerance

Back 14

Diarrhoea is a symptom
The undigested lactose is broke down in large intestine by micro-organisms. this creates soluble molecules that lower the water potential. Water then moves by osmosis from the epithelial cells into the lumen of the intestines.

Front 15

Describe how starch is digested

Back 15

Teeth break it into smaller pieces to increase surface area.
Saliva contain salivary amylase, which start hydrolysing starch into maltose.
In small intestine, pancreatic juices contains pancreatic amylase continue hydrolysis I starch to moltose because the preview enzymes where denatured in stomach.
Finally, lining if small intestine produces maltase, which hydrolyses the maltase into glucose

Front 16

How do enzymes speed up reactions?

Back 16

They lower activation energy needed for the reaction to take place

Front 17

Why are enzymes specific?

Back 17

Their shape of their active site is complementary to the specific substrate

Front 18

Describe lock and key model

Back 18

Enzymes are specific. The shape of the substrate (key) exactly fits the active site of the enzymes (lock)

Front 19

Name a limitation of lock and key model

Back 19

Locks are Considered rigid. Enzyme active stores are flexible

Front 20

Describe induced fit model

Back 20

Enzyme active site changes shape to fit precisely with substrate. The enzyme is flexible. As it changes shape the enzyme creates a particular bond and lowers the activation energy

Front 21

What 3 factors effect enzyme action?

Back 21

Temperature
PH
Substrate concentration

Front 22

What is the primary structure?

Back 22

Amino acids bonded by a condensation reaction. This forms a polypeptide chain

Front 23

What is the secondary structure?

Back 23

The polypeptide spontaneously folds into an alpha helix or a beta plated sheet. Different parts of the chain is held together by hydrogen bonds

Front 24

What is the tertiary structure?

Back 24

The polypeptide folds again to form a 3d structure.

Front 25

What is the quaternary structure?

Back 25

Two or more polypeptide chains linked together to form a single complex protein

Front 26

Describe and explain competitive inhibition

Back 26

The inhibitor is a similar shape to the subtrate. It competes with the substrate for the enzymes active site. This decreases probability that the enzyme will act on substrate, so rate of reaction decreases

Front 27

Describe and explain non competitive inhibitors

Back 27

Inhibitors attach to enzyme, making the active site shape change. Reaction rate decreases because some enzymes are unable to catalyse any subtrates