Human nutrition

What is a balanced diet?

"A balanced diet is a diet that contains all the required nutrients in suitable proportions, as well as the right amount of energy"

What are the required nutrients?

1. Carbohydrates

2. Fats and oils

3. Protein

4. Vitamins (C&D)

5. Minerals (calcium&iron)

6. Fibre (roughege)

What causes scurvy?

A vitamin C deficiency.

What causes rickets?

A lack of vitamin D

What is the function of carbohydrates?

It's(functions) a source of energy

What are the functions of lipids?

They insulate, and store energy

What are the functions of proteins?

Their function is for growth and repair.

What are vitamins (C&D) needed for?

They're needed in small amounts to maintain health.

What are mineral ions need for?

Thet are needed in small amounts to maintain health.

What is fibre (roughage) needed for?

It's needed to provide bulk (roughage) for the intestine to push through.

What is water needed for?

It's needed for chemical reactions to take place in cells.

Where are carbohydrates found?

In bread, cereal and pasta.

Where are lipids found?

In butter, oil and nuts.

Where are proteins found?

In meat, fish and eggs.

Where are vitamins found?

In fruits and vegetables.

What is ingestion?

The taking in of substances, such as food and drink, into the body, coming from the mouth.

What is digestion?

The chemical, or physical breaking down of food.

What is absorption?

The movement of nutrients from the small intestines, into the blood.

What is assimilation?

It's the uptake and use of nutrients by cells.

What is egestion?

The removal of undigested food from the body as faeces.

What is the digestive system made up of?

Mouth, oespophagus,stomach, duodenum and ilium (small intestine), colon and rectum (large intestine), liver, gallbladder and pancreas.

How does food go down the digestive system?

First food is ingested, this is followed by digestion, absorption, and assimilation. Food that cannot be absorbed is egested.

What does physical digestion?

The teeth and the stomach

What is physical digestion?

Breaking down large pieces of food into small ones.

What does chemical digestion?

Enzymes in the mouth, stomach and small intestine.

What is chemical digestion?

Breaking down large nutrient molecules to small ones, so that they can be absorbed.

How do teeth help in physical digestion?

They grind food into smaller pieces to increace it's surface area, allowing subsequent chemical digestion to happen faster.

What are the four types of teeth?

Incisors, canines, premolars and molars.

What does amylase do in chemocal digestion?

Amylase breaks down starch into simpler, reducing sugars.

What does protease do in chemocal digestion?

Protease breaks down proteins into amino acids.

What does lipase do in chemical digestion?

It breaks down fats into fatty acids and glycerol.

What does hydrochloric acid do in the stomach?

It provides a low pH for enzymes to work, and kills harmful microorganisms in food.

What does amylase do in the mouth and duodenum?

It breaks down starch to maltose.

What does maltase do to maltose in the small intestine?

Maltase breaks down maltose to glucose on the surface of the villi in the small intestine.

What is the protease in the stomach called?

It's pepsin.

What does pepsin need?

It needs a low pH which is supplied by the hydrochloric acid secreted in the gastric juice.

What protease does the pancrease secrete?

Tripsin.

What does trypsin need?

A higher pH than pepsin, which is provided by the alkaline substances in bile.

Where is bile found?

It's secreted by the liver, stored in the gallbladder, and released in the duodenum.

What does bile do?

It emulsifies fats, which makes it easier for lipase to digest them.

What does the small intestine absorb into blood?

Nutrients such as water are absorbed into blood from the small intestine.

Where is more water absorbed into the bloodstream?

In the colon.

How do villi and microvilli help with absorption?

They increace the surface area of the small intestine, which speeds up absorbtion.