Nutrients

• protein / amino acids are used to build and repair muscles.
• Fat's functions:

  • helps give your body energy
  • protects your organs
  • supports cell growth
  • keeps cholesterol and blood pressure under control
  • helps your body absorb vital nutrients
• What are the products of digestion used for?


  • glucose if for respiration
  • fats are used for protection and energy storage
  • amino acids are used for repairing muscles
• Biological Molecules (Nutrients) you need for a balanced diet:

  • Carbohydrates
  • Proteins
  • Lipids
  • Vitamins
  • Mineral ions
  • Fibre
  • Water
• Foods have a mix of different nutrients in.
• Carbohydrates

  Found in starchy food like: bread, pasta, potatoes, fruits and vegetables.


  provide energy we need for chemical reactions and to move around.

  
• The term 'Lipids' refers to both fats and oils:

  • A fats is a lipid that's solid at room temperature.
  • An Oil is a lipid that's liquid at room temperature, like olive oil.

  
• Lipids

  Found in oily fish, nuts & seeds, dairy products and avocado.

  • used to provide energy, but acts as a longer term store of energy.
  • used to keep up warm by insulating.
  • used to protect our organs.

  
• Proteins


  Found in nuts & seeds, meat, fish, legumes (lentils / beans).

  • Used for organisms to grow.
  • Used to repair damaged tissue.
  • Used for energy (when there's not enough carbohydrates / lipids).

  
• Vitamins / mineral ions:

  • comes in lots of different types.
  • only need them in small amounts
• Vitamins (organic molecules)


  Made by living organisms
• Minerals (inorganic)


  Simpler molecules
• Vitamins:

  • vitamin A
  • vitamin C
  • vitamin D
• Vitamin A


  Comes from foods like liver and leafy vegetables.

  • used for good vision
  • used for healthy skin and hair

  
• Vitamin C


  Comes from fruit and vegetables. Especially citrus fruits like oranges.

  • used to prevent a disease called "scurvy".

  
• Vitamin D


  The body can make it itself by using sunlight.

  Also comes from foods like eggs and oily fish.

  • Used to help the body to absorb calcium (a mineral ion).

  
• Ca - Calcium - mineral ion

  Found in dairy products (like milk) and leafy vegetables.

  • needs calcium for strong bones.

  If you don't eat enough / can't absorb it (not enough Vit. D) can lead to a condition called rickets, where your bones can be deformed.

  
• Fe - Iron - a mineral ion


  Can be found in red meat, spinach and beans.

  • Important component of haemoglobin.
  • Haemoglobin is a protein in red blood cells that allows them to transport oxygen around the body.

  A lack of iron (and hence haemoglobin), can lead to anaemia, where you can't transport enough oxygen to our tissues.

  
• Fibre


  A type of carbohydrate, but we don't absorb it into the body.

  Found in whole meal food like, bread, brown rice, fruits and vegetables.

  • its role is to help food to move through out intestine properly.
  • It stops us from getting diarrhoea and constipation

  
• Water


  We get it from our drinks and even food like oranges and strawberries (as they are mostly water).

  • used for chemical reactions.
  • Our bodies are filled with 70% water and it's continuously losing water from:Used to replace the 70% water in
• Water



  We get it from our drinks and even food like oranges and strawberries (as they are mostly water).

  • used for chemical reactions.
  • Our bodies are filled with 70% water and it's continuously losing water from:
  • Breathing
  • Sweating
  • urinating
  • So it needs to replace it all.

  
• balanced diet

  A diet that includes appropriate proportions of all the different biological molecules. 
• • Too much of any biological molecule could lead to obesity.
  • Too little of any biological molecule could lead to a disease, like scurvy.
• We get energy from the food we eat.

  In physics, energy is measured in Joules (J). 

  In the case of food, energy is measured in calories.

  
• Main factors that depends on the amount of energy we need:

  • Activity level
  • Age
  • Pregnancy
• Activity level


  The more active you are, if you're an athlete, the more energy you need.
• Age 


  Teenagers often need a lot of energy because they're growing, whereas elderly people need less.
• Pregnancy


  Pregnant women need more energy because the baby growing inside them requires a lot of energy.
• Biological molecules


  Molecules found in living organisms and are produced by cells.
• Nutrients


  Substances that are needed for growth, repair and metabolism.
• Metabolism


  chemical reactions in the body's cells that change food into energy.
• Carbohydrates are molecules made from atoms of:

  • carbon
  • hydrogen
  • oxygen

  (The carbohydrate in the image is glucose).

  
• • Carbohydrates come in different sizes, with the smallest being simple sugars, (like glucose and fructose).
  • The simple sugars are called 'monomers'.
  • Carbohydrate monomers can join together to form carbohydrate polymers (like glycogen and starch).

  
• • In a complex carbohydrate, there are chemical bonds between the monomers.
  • If the bonds are broken, the complex carbohydrates are broken down into simple carbohydrates.

  (e.g. starch can be broken down into glucose molecules).

  
• Amylase enzymes produced by the salivary glands in the mouth and carbohydrase enzymes produced by the small intestine breaks down complex carbohydrates into simple carbohydrates (simple sugars).

  
• • Proteins are made up of long chains of amino acids bonded together.  
  • A protein is a polymer, while the amino acids it's made from are the monomers.

  A) amino acids

  B) protein

  
• Amino acids are mainly made from atoms of:

  • carbon
  • hydrogen
  • oxygen
  • nitrogen

  
• Pepsin enzymes (a type of protease enzyme) produced in the stomach and protease enzymes produced in the small intestine break proteins down into amino acids.

  
• Lipids contain a single glycerol molecule attached to three fatty acid molecules.

  
• • The fatty acid molecules are often different lengths
  • it's the length and structure of the fatty acid molecules that determines whether a lipid is a fat or an oil.