Topic 1 - Enzymes Flashcards
What are enzymes?
Biological catalysts
Proteins that speed up chemical reactions
In a reaction which part of the enzyme changes?
The substrate
What is an active site?
The part where it joins onto its substrate to catalyse the reaction
Do enzymes work with many substrates?
No they only work with one. They have a high specificity for their substrate
How does the enzyme work for a reaction to be catalysed?
The substrate has to fit into the active site. If the substrate doesn’t match the active sites shape then the reaction won’t be catalysed.
What enzyme is found in the stomach?
Pepsin
Protease function
Breaks down proteins into amino acids
Where is carbohydrase found in the body?
Mouth (amylase) and small intestine
pH of mouth
pH 7
Carbohydrase function
Breaks down starch in glucose and other simple sugars
Lipase function
Breaks down lipids (fats) into fatty acids and glycerol
Where is protease found in the body?
Stomach
Where are lipids found in the body?
Small intestine
What is bile?
Made in the liver , aids digestion of lipids in the small intestine , stored in gallbladder , neutralises food from the stomach
pH of stomach
pH 2
pH of small intestine
7.5-8
What is the lock and key model?
Model of the enzyme with substrate fitting perfectly into the active site to get broken down, making enzymes highly specific
What is denaturing?
When the shape of an enzymes active site changes.
What is rate of reaction?
Amount of substrate used or amount of product formed/time taken.
3 things that affect enzyme activity
pH, temperature and substrate concentration
How do you find the rate of reaction for enzyme activity?
Rate = 1000 / time
