GSCE AQA Biology Chapter 3- Organisation and The Digestive System

What breaks down carbohydrases?

Amylase

Where is amylase made?

The Pancreas and Salivary Gland

Where does amylase act?

The salivary gland and small intestine

What breaks down protiens?

Protease

Where is protease produced?

The pancreas, stomach and small intestine

Where does protease act?

The stomach and small intestine

What breaks down lipids/fats?

Lipase

Where is Lipase made?

The pancreas and small intestine

Where does Lipase act?

The small intestine

What does bile do inside the body (two points)

• Neutralises acid added to the food in the stomach

• Emulsifies fats

Why does bile emulsify fats?

To provide a bigger surface are for lipase to work on

What tests are used for carbohydrates?

• iodine test (for starch): yellow liquid turns blue / black

• benedicts test (for sugars): blue/black solution turns brick red on heating

What test in used for lipids?

Ethanol test: ethanol added to solution gives a cloudy white colour

What test is used for protiens?

Biuret test: turns blue to purple

What is metabolism?

Controlled by enzymes, the sum of all the different rates of reaction in the body.

What do enzymes speed up? (3 bullet points)

• building large molecules from smaller ones

• breaking down large molecules into smaller ones

• changing one molecule into another.