Nutrition

What are carbohydrates made of?

They contain carbon, hydrogen and oxygen.

Starch and glycogen are large carbohydrates, which are made up of smaller units like glucose and molecules joined together in a large chain.

What are proteins made of?

Long chains of amino acids.

Carbon, nitrogen, hydrogen and oxygen

What are lipids made of?

Fatty acids and glycerol

Carbon, hydrogen, and oxygen

How do you test for glucose?

Benedict’s solution

1. Water bath of 75C

2. Benedict’s solution

3. From blue to green (low), yellow (medium), or brick-red (high)

How do you test for starch?

Iodine solution

1. Add iodine solution and gently shake

2. Solution changes from brown-orange to blue-black

How do you test for proteins?

Biuret’s test

1. Biuret solution and gently shake

2. From blue to pink or purple

How to test for lipids?

Sudan III stain solution

1. Add Sudan III solution and gently shake

2. Stains lipids. If lipid is present, mixture will separate into two layers and top layer will be bright red

What foods do you need to eat?

Carbohydrtes

Lipids

Proteins

Vitamins (A, C, D)

Mineral ions (Calcium, Iron)

water

Dietary fibre

Where are carbohydrates found in and what is its function?

Pasta, rice, sugar

Provides energy

Where are lipids found in and what is its function?

Butter, oily fish

Provides energy and acts as an energy store and provides insulation

Where are proteins found in and what is its function?

Meat, fish

Growth and repair of tissue

Where are the three vitamins found in and what is its function?

A - Liver

Improve vision and keeps skin and hair healthy

C - Fruit

Prevents scurvy

D - Eggs

For calcium absorption

Where are mineral ions found in and what is its function?

Calcium - Milk, cheese

Bones and teeth

Iron - Red meat

Haemoglobin for healthy blood

Where is water found in and what is its function?

Food and drink

every bodily function

Where is dietary fibre found in and what is its function?

Wholemeal bread, fruit

Aids movement of food through gut

What is a balanced diet?

Essential nutrients in the right proportions

What enzyme breaks down starch?

Amylase breaks down starch into maltose

What enzyme breaks down maltase?

Maltase enzyme breaks it down into glucose

What enzyme breaks down proteins?

Protease enzymes break it down into amino acids

What enzyme breaks down lipids?

Lipase converts it to glycerol and then fatty acids

What enzymes is found in the mouth?

Salivary glands produce amylase enzymes in the saliva

Teeth break down food

Where is bile produced?

Liver

Where is bile stored?

Gall bladder

Where is excess water from food absorbed?

Large intestine

Where is shit stored?

Rectum

What happens in the stomach?

1. Breaks down food with muscular walls

2. Produces protease enzyme and pepsin

3. Produces hydrochloric acid to:

• Kill bacteria

• Optimum pH for protease enzyme to work (pH 2)

What happens in the pancreas?

Produces protease, amylase and lipase, releasing it into small intestine

What happens in the small intestine?

1. Produces protease, amylase and lipase to complete digestion

2. Absorbs nutrients into the body

   1. First part is called duodenum, second part is called ileum

What does bile do?

Neutralises stomach acid and emulsifies fats

1. Produced in liver and stored in gall bladder

2. Hydrochloric acid makes pH too acidic for enzymes in small intestine.

3. Emulsifies fat and makes SA bigger to make lipase faster to make digestion faster

How is food moved through the gut?

Through peristalsis

What do villi in the small intestine do?

They help with absorption.

1. Big SA in small intestine because of villi

2. Each cell has microvilli to increase SA

3. Single permeable layer of surface cells and a good blood supply to assist quick absorption

What are pathogens?

Bacteria that cause disease. They include fungi, protocists, and bacteria and viruses but they are not living