Enzymes and Digestion Flashcards
What are enzymes and what are they needed for
Biological catalysts. They reduce the need for high temperatures and we only have enzymes to speed up the useful chemical reactions in our body
What is a catalyst
A substance which increases the speed of a reaction, without being changed or used up in the reaction
Why does an ezyme only usually catalyse one specific reaction
They each have a unique shape and for it to work, the substrate has to fit into its active site, if it doesn’t fit then the reaction won’t be catalysed
What happens to the enzyme if the temperature is too hot or there is too much pH
The bonds break and the enzyme is denatured (too hot)
Interferes with the bonds holding enzymes together and it becomes denatured (too much pH)
What is the formula for the rate of reaction
Rate = 1000÷ time
How do BIG molecules like starch pass throug the walls of the digestive system
Digestive enzymes break them down into smaller molecules like glycerol that can pass easily through the walls
What does bile do
It neutrilises stomach acids and gives enzymes the alkaline conditions, which they work best in, and it emulsifies fats which makes digestion faster
Breakdown of food
Salivary glands- produce amylase in the saliva
Stomach- pummels food, produces protease and hydrochloric acid
Liver- produces bile
Pancreas- produces protease, amylase, lipase so release to small intestine
Gall bladder- stores bile and releases to small intestine
Small intestine- digested food is absorbed into the blood, produces protease, amylase and lipase
Large intestine- excess water is absorbed from food
Rectum- where faeces are stored
Different digestion for carbs, protein and lipids
Carbohydrases break down carbohydrates to simple sugars. Amylase is a carbohydrase which breaks down starch.
Proteases break down proteins to amino acids.
Lipases break down lipids (fats) to glycerol and fatty acids.
The lock and key theory
The substrate binds to the active site because the shape of the active site and substrate are complementary then a chemical reaction occurs to produce smaller molecules
