Carbohydrates Flashcards
What are carbohydrates formed from?
Carbon, hydrogen and oxygen
What are the two types of carbohydrate?
Sugar
Complex carbohydrates
What are the functions of carbohydrates in the diet?
They provide the body with energy for physical activity and bodily functions
They provide dietary fibre to help digestion
Sugars also sweeten and flavour foods
What are monosaccharides?
They are simple sugars that can be absorbed very quickly by the body
What are the three monosaccharides?
Glucose, fructose, galactose
Describe glucose:
Glucose is found in some fruits and vegetables, it is often used by athletes in tablet or powder form to provide a fast energy boost
Describe fructose:
It is similar in structure to glucose and is found naturally in the juices of some fruits and plants, but mainly in honey.
Describe galactose:
It is formed during the digestion of lactose (milk sugar)
What are disaccharides?
Disaccharides are double sugars that are made up of two monosaccharides
What are the three disaccharides?
Lactose, maltose, sucrose
Describe lactose
It is the disaccharide found in milk, which gives milk its sweet taste
Describe maltose
A product from the fermentation of cereal grains
Describe sucrose
Most common disaccharide, known as sugar
Provides the body with energy but has no other benefits in the diet as it contains no other nutrients
What are the two forms of sugar?
Non-free sugar
Free sugar
Sources of non free sugar
Found naturally in the cells of fruits and vegetables
Sources of free sugar
Sugar that you can see, such as cane sugar, syrup, and those added to cakes, biscuits, desserts and sweets
What is a polysaccharide?
They are complex carbohydrates formed from hundreds of glucose molecules joined together. They provide the body with energy
Examples of polysaccharides:
Starch NSP Dextrin Pectin Cellulose
What is starch?
Starches take longer than sugar for the body to digest and so provide a feeling of fullness for longer, helping to avoid overeating and obesity
Functions of starch in our diet:
Provides a slow release of energy as it is broken down slowly
It adds bulk to our diet
It gives a feeling of fullness
Excess is converted into fat
Sources of starch:
It is found in grain products such as bread, rice, cereals and pasta
What is NSP?
NSP stands for non-starch polysaccharide
It is the non-digestible cellulose found in plant foods.
It cannot be digested so it passes straight through the digestive system, absorbing moisture and providing bulk.
It helps ‘push’ other food through the system and helps to ‘clean’ the walls of the intestine of bacteria.
What is the recommended amount of fibre for adults?
30g/day
What are the functions for dietary fibre?
Holds water and keeps the faces soft and bulky
Helps prevent various bowel disorders e.g. constipation, bowel cancer, diverticular disease
Can help people to control their body weight because high fibre foods are filling
High-fibre diets are linked to lower blood cholesterol whilst reducing the risk of diabetes
What is the effect of a deficiency of fibre?
Causes constipation, diverticular disease, bowel cancer
What are the two types of dietary fibre?
Soluble and insoluble
What is insoluble fibre?
Insoluble fibre absorbs water and increases bulk, making the faeces very soft and bulky and easy to pass through the digestive system
What are good sources of insoluble fibre?
Wholemeal flour
Wholegrain breakfast cereals and pasta
Brown rice
Some fruit and veg
What is soluble fibre?
Soluble fibre slows down the digestion and absorption of carbohydrates and so helps to control blood sugar levels, which helps stop us feeling hungry.
It may also reduce blood cholesterol levels and so may reduce our risk of heart disease
What are good sources of soluble fibre?
Oats
Peas, beans and lentils
Most fruit and veg (more fibre with their skins on)
