SEHS UNIT 3 ENERGY SYSTEMS - 3.1 NUTRITION

List the macronutrients

Carbohydrates, proteins, lipids (fats) and water

List the micronutrients

Vitamins, minerals

What do macronutrients do?

Provide the energy necessary to maintain bodily functions during rest, and diverse physical activity.

What do micronutrients do?

Facilitate energy transfer and tissue synthesis.

Functions of carbohydrates

Provide fuel for the body.

Acts as an energy storage.

Breaks down fatty acids and prevents ketosis (elevated level of ketone in the blood)

Sources of carbohydrates

Pasta, cereals, quinoa

Functions of proteins

Structure and transport.

Repair and growth of muscles and tissues.

Fuel for the body

Sources of proteins

Meat

Fish

Eggs

Dairy

Nuts

Pulses

Functions of lipids (fats)

Low intensity exercise energy source.

Backup energy in carbohydrates are low.

Protects vital organs (heart, lungs, liver etc.)

Thermal insulation (cold climates)

Sources of lipids (fats)

Meat

Avocados

Dairy

Oils

Eggs

Functions of water

Prevents dehydration

Allows biochemical reactions to occur

Transport

Thermoregulation

Excretion

Lubrication in joints

Sources of water

Beverages (drinks)

Fruit (watermelons)

Vegetables (cucumber)

Functions of vitamins

Energy release from macronutrients

Promotes healthy bones and blood

Increases immune function

Sources of vitamins

Fruits

Vegetables

Fatty fish (salmon)

Functions of minerals

Aids absorption of vitamins

Strengths bones and teeth

Promotes blood oxygen transport

Aids muscle function

Sources of minerals

Fruit

Vegetables (kale)

Fish

Functions of fibre

Helps avoid constipation

Bulk up consumed food

Sources of fibre

Beans

Nuts

Rice

Cereal

Fruit

Vegetables

Chemical composition of a glucose molecule

C = Carbon H = Hydrogen O = Oxygen

1:2:1 ratio

Diagram of basic structure of a glucose molecule

Carbon: 6

Hydrogen: 12

Oxygen: 6

How glucose molecules can combine to form disaccharides and polysaccharides

Condensation reaction: the linking of a glucose molecule to another glucose molecule by losing a water molecule.

One oxygen molecule is left behind and so attaches on to the other glucose molecule (glycosidic bond)

Disaccharide: 2 glucose molecules are combined

Polysaccharides: more than 2 glucose molecules are combined

Composition of a triacylglycerol molecule

Glycerol and 3 fatty acids

Glycerol is an alcohol with the formula C3H8O3 - it contains three hydroxyl groups (OH)

Fatty acids are long chain hydrocarbons containing carboxyl (COOH) group at one end

Difference between saturated and unsaturated fatty acids

Saturated Fatty Acids:- Have no double bonds between individual carbon atoms of the fatty acid chain

Unsaturated Fatty Acids:- Contain one or more double bonds between carbon atoms within the fatty acid chain

Examples of saturated fats

Meat

Poultry

Full fat dairy

Coconut oils

Examples of unsaturated fats

Olive oil

Olives

Avocados

Canola Oil

Peanuts

Chemical composition of a protein molecule

Carbon: 1

Hydrogen: 1

Oxygen: 1

Nitrogen: 1

Difference between an essential and a non-essential amino acid

Essential amino acids cannot be made by the body. As a result, they must come from food.

Non-essential amino acids are produced by bodily systems.

Current recommendations for a healthy diet

Carbohydrates = 45-55%

Proteins = 10-35%

Lipids = 20-35%

Unsaturated fats = 20-30%

Saturated fats = <10%

Fibre = 3-5%

Salt = < 6g

Water = 3l

What is the main differences between Mediterranean, SE Asian, Western and South Asian diets

Mediterranean: Paella, pies, chorizo, olive oil

SE Asian: Sushi, rice, fish

Western: Roast chicken, pies, hamburgers

South Asian: Rice, curry, naan breads

Approximate energy content per 100g of carbohydrate, lipid and protein

Carbohydrates: 1,760 kJ per 100 g

Proteins: 1,720 kJ per 100 g

Fats: 4,000 kJ per 100 g

Recommended energy distribution of the dietary macronutrients differs between endurance athletes and non-athletes

Calorie difference:

Carbohydrates: Athletes consume significantly more

Proteins: Athletes consume considerably more

Fats: Athletes consume slightly more

Percentage difference:

Carbohydrates: Athletes consume slightly more

Proteins: Athletes consume slightly more

Fats: Athletes consume considerably less