Diet and Teeth - IGCSE Biology - Unit 7

HCA 4th Year Health and Adolescence Exam

What is diet?

The food an animal eats every day

What is a balanced diet?

A diet that contains all the required nutrients in suitable proportions and the right amount of energy

Which nutrients must be in a human diet?

7 nutrients. Carbohydrates, protein, minerals, vitamins, fats and oils, water and fibre (which although not a nutrient is an essential component)

What is fibre?

A part of food that passes through the digestive system without being absorbed

Why is fibre important?

It keeps the digestive system working and prevents constipation

What are daily energy requirements based on?

Age, sex and job

What are teenage energy requirements?

High and balanced as their bodies are physically in development.

What happens if you eat too much food?

Excess energy is stored as fat

What happens if you eat too little food?

You feel tired due to lack of energy

Which nutrient provides the most energy per gram?

Fat (twice as much as carbs or protein)

Why do pregnant women need more nutrients?

To support the baby’s growth (more food intake)

Why do older people need less food?

Their metabolism slows down with age

What are carbohydrates used for?

Providing energy for cellular respiration.

Sources of carbohydrates?

Potatoes, sugar foods and staple starchy foods

What are fats and oils used for?

Energy and insulation in the body as well as cell membrane structure.

Sources of fats and oils?

Cooking oils, oily fish such as salmon, dairy products, eggs, meat

What are proteins used for?

Building new cells (growth) and protein synthesis.

Sources of proteins?

Meat, fish, eggs, dairy products, legumes, nuts, and seeds.

What are vitamins?

Organic substances needed in tiny amounts to stay healthy

What is Vitamin C used for?

Making collagen and keeping tissues healthy

Sources of Vitamin C?

Citrus fruits and raw vegetables

What is Vitamin C deficiency called?

Scurvy – causes joint pain and bleeding gums

What is Vitamin D used for?

Absorbing calcium and building bones and teeth

Sources of Vitamin D?

Butter, egg yolk (Ingested)
Sunlight (absorbed by skin)

What is Vitamin D deficiency called?

Rickets – soft and deformed bones (mainly in children, leading to growth issues).

What are minerals?

Inorganic substances needed in small amounts

What is iron used for?

Making haemoglobin which carries oxygen in the blood

Sources of iron?

Liver, red meat, egg yolk

What is iron deficiency called?

Anaemia – too few red blood cells

What is calcium used for?

Building bones and teeth

Sources of calcium?

Milk, other dairy products and bread.

What does calcium deficiency cause?

Brittle bones/teeth

Why is water important?

It's a solvent for reactions, removes waste products such as urea, composes plasma, and aids in digestion.

WRD-T= Waste, reactions, digestion, transport.

Where do we get water from?

Drinking fluids and eating foods like fruit

What percentage of the human body is water?

More than 60%

What is peristalsis?

Muscle contractions that move food through the digestive system

How does fibre help peristalsis?

It stimulates muscle movement

Why can’t humans digest cellulose?

We don’t have the enzymes to break it down

What do teeth do in digestion?

Help with ingestion and mechanical digestion by breaking food into smaller pieces

Why is mechanical digestion important?

It increases surface area for enzyme action and helps dissolve food in saliva

What is enamel?

The hardest substance in the body

How is enamel damaged?

By acids from bacteria that feed on sweet foods which consequently causes tooth decay.

What is dentine?

The layer under enamel

What is the pulp cavity?

The center of the tooth which is filled with nerves and blood vessels

What is cement in a tooth?

A layer that attaches the tooth to the jawbone and allows slight movement

What are incisors for?

Biting off pieces of food

What are canines for?

Tearing food

What are premolars for?

Chewing food

What are molars for?

Grinding food at the back of the mouth