2.2.1 Digestion And Enzymes Flashcards
Digestion
The breaking down of large insoluble molecules of food into smaller soluble molecules
They can be absorbed into the bloodstream
Why is digestion necessary
To make sure molecules can be absorbed though the partially permeable membrane and into the blood stream
Substrate
The chemical at the start of the reaction
Active site
The part of the enzyme where the substrate binds
Complementary
When substrate and active site have shapes that fit together
Physical digestion
First stage of digestion
Its quick and breaks down large chunks of food into smaller bits
Example of physical digestion
Chewing
Chemical digestion
Second stage of digestion
Slower process and chemically breaks down large insoluble molecules into smaller, soluble ones
Examples of chemical digestion
Enzymes
Digestion by enzymes
Fates are emulsified
Lock and key hypothesis method
- The substrates are complementary, so they will fit together
- the substrate goes in the active site, and the reaction occurs
- 2 substrates are joined together
- Enzyme can be reused
Lock and key hypothesis
A theory of enzyme action that explains how enzymes fit their substrate
Why are enzymes specific to one or only a few substrates
Other substrates have the wrong shape so they won’t fit because they aren’t complementary
Amylase
Breaks down carbohydrates into sugar
Protease
Breaks down protein into amino acids
Lipase
breaks down lipids into glycerol and fatty acids
