Nutrients Flashcards
(45 cards)
What is a balanced diet?
It contains the adequate amount of nutrients to maintain good health. The purpose is to provide energy for the growth and repair of cells and for the proper functioning of our vital organs
What are the five main groups of nutrients?
Carbohydrates
Proteins
Fats(lipids)
Vitamins
Minerals
Except for nutrients what else if essential for a balanced diet?
Water and dietary fibre
Why are water and dietary fibre not considered nutrients?
They are not digested by the body
How is water and dietary fibre important?
Water
- used as a solvent- many chemical reactions in the body occurs in a aqueous medium
- dissolves substances in the body so it’s used to transport of nutrients, hormones etc
- used to control body temperature. Water is a component of sweat. When sweat evaporates from the skin, the body cools down
Dietary fibre- also called roughage. It moves food through the alimentary canal thus preventing bowel diseases such as constipation and colon cancer.
What are carbohydrates?
Organic molecules made of hydrogen, oxygen and carbon
What are the 3 main groups of carbohydrates?
Monosaccharides
Disaccharides
Polysaccharides
What are monosaccharides?
Give examples
The simplest carbohydrate. Made of one sugar molecule
Example- glucose, fructose, galactose
How do we get disaccharides?
When two monosaccharides combine they undergo a reaction called condensation and a water molecule is removed.
How can disaccharides break down into monosaccharides?
Using hydrolysis where a water molecule is added.
What are polysaccharides?
Give examples
They consist of many polysaccharides joined together under a condensation reaction.
Examples- starch, glycogen, cellulose
What happens when polysaccharides are hydrolysed and what do they need to do it?
They break down into disaccharides and monosaccharides. They require enzymes to speed up the reaction.
What are some functions of carbohydrates
Source or energy- they are oxidized during respiration to produce energy
A storage of energy- excess glucose in animals are stored as fat or glycogen, excess glucose in plants are stored as starch
A source of dietary fibre- cellulose in plants cell wall cannot be digested by humans but provide dietary fibre in the diet.
Food containing carbohydrates mainly come from?
Sugars and starch
What are fats?
Fasts are organic molecules made of carbon hydrogen and oxygen.
They are apart of a groups called lipids.
Fats are lipids that are solid at room temperature and oils are lipids that are liquids at room temperature.
What are fat molecules made of?
Fatty acids and glycerol
How are fats broken down into fatty acids and glycerol?
During hydrolysis fats are broken down in fatty acids and glycerol with the use of an enzyme and addition of water.
What are some functions of fats?
- used as an alternative source of energy and storage after carbohydrates are used up
- Essential,component of cell membrane
- use as a solvent for synthesis, transport and absorption of vitamins and hormones
- used as a insulation material for animals to reduce the loss of body heat
What kind of fats are mostly found in animals? And explain the fat
Saturated fats- unhealthy and can cause coronary heart disease
What are unsaturated fats?
Give examples
They are healthier and used to replace saturated fats in our diet as much as possible
Example- nuts , vegetable oil, fish
What is protein?
An organic molecule of long chains of amino acids made up of hydrogen, oxygen, carbon and nitrogen
How many kinds of amino acids are there?
20
How do plants and animals/humans get the 20 amino acids they need?
Green Plants can manufacture all the amino acids they need
Humans and animals need to obtain 8 from their food(essential amino acids)
The body can make the other 12(non essential amino acids)
How are polypeptides formed?
When amino acids link together in a condensation reaction
