Nutrition and Metabolism Flashcards
Nutition
Nutrients are provided by the food we eat
Metabolism
The cells use the nutrients to carry out chemical and physical reactions in order for the cells continual function and growth
3 reasons why we need nutrients
1) Growth
2) Repair
3) Maintenance
6 examples of nutrients
1) Fats
2) Proteins
3) Carbohydrates
4) Water
5) Minerals
6) Vitamins
Micronutrients
What the body requires in small amounts.
Ex = vitamins and minerals
Macronutrients
What the body requires in large amounts.
Ex = Fats, proteins, carbohydrates and water
Essential nutrients
Nutrients that the body cannot produce itself and therefore requires to be taken in from the diet.
3 main types of carbohydrates
1) Monosaccharides
2) Disaccharides
3) Polysaccharides
Monosaccharides
1) Glucose
2) Galactose
3) Fructose
Disaccharides
1) Maltose (1 glucose and 1 glucose) mag mag 2) Sucrose (1 glucose and 1 fructose) my GF sucs 3) Lactose (1 glucose and 1 galactose) LG gal
Polysaccharides1
1) Starch
2) Glycogen (small amounts in cooked meat)
3) Cellulose (important fibre source - but humans cannot digest cellulose)
3 uses of glucose:
1) Glucose is readily taken up by cells and used to produce ATP.
2) To produce Glycogen stores (any excess glucose will be converted and stored as fat)
3) Forms structural part of some molecules (e.g. glycoproteins)
2 cells which depend of glucose to form ATP:
1) Neurons
2) Erythrocytes
What is the approx. GDA for carbohydrates?
230g/day (greater requirement than other nutrients)
What is the main source of carbohydrates?
Plant material
Why are polysaccharides the best form of carbohydrate?
It requires more energy to be broken down and so allows for a stable release of glucose.
What is Fibre?
Fibre is a plant or animal carbohydrate which resists being digested by the body.
What are the 2 effects of fibre?
1) Absorbs water into the intestines which softens the stools.
2) Provides bulk - which speeds up the transit time.
What is the approx. GDA for fibre?
24g/day
What is the problem with having too much fibre?
Interfere with mineral absorption from the digestive tract into the circulation
How much of our body mass is proteins?
12-15%
Proteins are made up of
amino acids
Transamination
The process whereby an amino group from one molecule is transferred to another - in order to synthesis and degrade amino acids.
Takes place in the liver.
How many amino acids are there?
20
How many amino acids are essential amino acids?
8
What is the approx. GDA for proteins and what does it depend on?
45-60g/day (sex and age)
In what circumstances does your GDA for protein need to increase?
1) In Pregnancy
2) Growing children
3) Training for something
2 components that make up an amino acid?
1) Amino group
2) Carboxyl group
What are the 2 sources of proteinss and their definition, products and examples?
1) Complete proteins = Proteins that contain all 8 of the essential amino acids. Found in animal products (e.g. eggs, milk and animal meat)
2) Incomplete proteins = Proteins that are lacking 1 or more of the 8 essential amino acids. Found in plat products (e.g. baked bead, kidney beans and rice)
What percentage of the body is fat (male and female)?
Adult male: 15%
Adult female: 25%
What are the uses of fat?
1) Energy storage
2) Absorption of fat-soluble vitamins
3) Used to produce plasma membrane and myelin sheath
What substances are made from fats?
1) Steriods
2) Bile
3) Salts
4) Prostaglandins
5) Vitamin D
What is the approx. GDA for lipids?
70g/day (20g of which should be saturated fats)
3 sources of lipids:
1) Saturated fats (animal origin)
2) Unsaturated fats (e.g. nuts and seeds)
3) Cholesterol (important for cell membranes)
What is a fat cell called?
Adipocyte