Carbohydrates

• What is photosynthesis?


  The process where green plants trap energy from the sun and form carbohydrates
• What are sugars?


  Group of carbohydrates that taste sweet
• What are monosaccharides?


  Group of sugars that are made of one sugar molecule
• What are disaccharides?


  Group of sugars that are made of two sugar molecules
• What are polysaccharides (complex carbohydrates)?


  Group of carbohydrates that are made from many sugar molecules joined together, but do not taste sweet
• What is carbohydrate?


  Carbohydrate is a macronutrient that is needed by all animals. It is made by green plants during a process called photosynthesis
• Functions of carbohydrate in the body

  Carbohydrate has two main functions in the body:

  1. To give the body energy: carbohydrates are the main source of energy in our diet
  2. To help the body get rid of waste products: dietary fibre is a type of carbohydrate that helps us to produce soft, bulky faeces (solid waste), which are easy to pass out of our body when we go to the toilet
• Type of carbohydrate - sugars: Monosaccharides


  Main sources

  Glucose: ripe fruits and vegetables (e.g. apples, onions, beetroot, parsnip, sweet potato). Also available in drinks, tablets and powders

  Fructose: fruits, vegetables and honey. High fructose corn syrup (HFCS) is used as a sweetener in many processed foods and carbonated soft drinks

  Galactose: milk from mammals
• Type of carbohydrate - sugars: Disaccharides

  Main sources:

  Maltose: cereals such as barley, also available as a syrup (malt extract), added to commercially made breakfast cereals, biscuits, hot drink powders, confectionery

  Sucrose: extracted from sugar cane and sugar beet and used in cooking and many processed foods, drinks and confectionery. Commonly known as 'sugar' (e.g. caster, granulated, brown, demerara, icing and golden syrup)

  Lactose: milk from mammals and products made from it (e.g. yogurt, evaporated milk, cheese).
• What are the two groups of carbohydrates in the diet?

  Sugars and complex carbohydrates
• What distinguishes sugars from complex carbohydrates?

  Sugars taste sweet, while complex carbohydrates do not
• What are the two types of sugars produced by plants during photosynthesis?

  Monosaccharides and disaccharides
• What is a monosaccharide?

  A monosaccharide is made of one sugar molecule
• Name three examples of monosaccharides.

  Glucose, galactose, and fructose
• What is a disaccharide?

  A disaccharide is made of two sugar molecules joined together
• Name three examples of disaccharides.

  Sucrose, lactose, and maltose
• What are complex carbohydrates also known as?

  Polysaccharides
• How do complex carbohydrates differ from sugars in terms of taste?


  Complex carbohydrates do not taste sweet
• What are some examples of polysaccharides produced by plants?

  Starch, pectin, dextrin, and dietary fibre
• What polysaccharide do animals (including humans) produce from carbohydrates?

  Glycogen
• How is glycogen related to carbohydrates in the diet?

  Glycogen is made from the carbohydrates that animals eat
• What are the main sources of carbohydrates in the diet?

  • Sugars
  • Monosaccharides: glucose, galactose, fructose
  • Disaccharides: sucrose, lactose, maltose
  • Complex carbohydrates (polysaccharides)
  • Examples: starch, pectin, dextrin, dietary fibre (NSP)
  • Glycogen produced by animals from carbohydrates
• What type of carbohydrate are polysaccharides classified as?

  Complex carbohydrates
• What are the main sources of starch?

  • Cereals: wheat, rice, oats, barley, maize (corn)
  • Cereal products: breakfast cereals, pasta, bread, cakes, pastry, biscuits
  • Starchy vegetables: potatoes, yams, sweet potatoes, parsnip, pumpkin, butternut squash, peas, beans, lentils
  • Seeds, quinoa
• What are the main sources of dietary fibre (non-starch polysaccharide)?

  • Wholegrain cereals and cereal products: breakfast cereals, bread, pasta, flour
  • Fruits and vegetables, especially with skins left on: peas, beans, lentils
  • Seeds, nuts
• What are the main sources of pectin?


  • Some fruits: oranges, citrus fruit peel (lemons, oranges, limes), apples, apricots, plums, greengages
  • Some root vegetables: carrots
• How is dextrin formed?


  Dextrin is formed when starchy foods are baked or toasted.
• What is a common use for commercially prepared dextrins?

  They are used as thickening agents in salad dressings and sauces.
• Is a deficiency of carbohydrates common in the developed world?

  No, it is rare.
• What happens to blood sugar levels when insufficient carbohydrates are consumed?

  The blood sugar level drops.
• What is a common symptom of carbohydrate deficiency related to energy levels?

  Lack of energy or tiredness (fatigue).
• What does the body use for energy when carbohydrate intake is insufficient?

  The body starts to use energy stored in fat cells.
• What are the types of fat the body uses for energy during carbohydrate deficiency?

  Adipose tissue and visceral fat.
• What is the consequence of prolonged carbohydrate deficiency on body weight?

  The person will lose weight over a period of time.
• What happens to the body when fat stores are depleted due to carbohydrate deficiency?

  The body starts to break down protein from muscles to obtain energy.
• Which part of the body must receive energy even when carbohydrates are deficient?

  The brain and vital organs.
• How does the body prioritize energy sources during carbohydrate deficiency?

  The body prioritizes energy for the brain and vital organs before using muscle protein.
• What happens to excess carbohydrates in the diet?

  They are converted into fat and stored in the body.
• What could be a consequence of storing surplus energy from carbohydrates?

  It could lead to obesity if not used up in physical activity.
• What types of carbohydrate foods are quickly broken down and absorbed in the body?

  Refined and processed carbohydrate foods like sugar, sugary foods, and white bread.