Carbohydrates Flashcards
Function for carbohydrates
To supply the body with energy
How much energy is in 1g of pure starch or sugar?
3.75 kcal
Name the three types of carbohydrates
Starchy carbohydrates
Sugary carbohydrates
Non starch polysaccharide (NSP or fibre)
Explain how starch provides us with energy
It’s formed from thousands of glucose units joined together, so when starch is digested, the big molecule is gradually broken down into smaller pieces and as this happens energy is released.
Sources of starch
Potatoes Bread Rice Pasta Breakfast cereals Cous cous, quinoa
Explain how sugar provides energy
It’s a small molecule that can be digested quickly - provides an immediate, but short-lived, supply of energy.
Examples of sugary foods
Sweets Cakes/buns Biscuits Chocolate Fizzy drinks Fruit juices Jam/marmalade Ice cream
Adults are advised to have an intake of …g of NSP (fibre) per day.
18g
Sources of insoluble NSP
Wholegrain: - breakfast cereals
- bread
- (brown) pasta
- (brown) rice
Nuts
Pulses (peas, beans, lentils)Function of insoluble NSP
Acts like a sponge and absorbs water to add bulk to the faeces, making it soft and easily removed from the body.
Benefits of insoluble NSP
Reduces the risk of constipation, diverticular disease & bowel cancer.
Explain the process of constipation
The faeces become very hard and move slowly through the intestine - a lot of effort is required to move them. It can result in abdominal discomfort and a general feeling of ill health.
Explain diverticular disease
May develop if the faeces are small and hard (due to lack of NSP and insufficient water). The muscular walls of the intestine have to work harder to move them along, causing increased pressure, leading to pouches of the bowel lining being forced out through the intestine wall. If the pouches (diverticula) become inflamed, it’ll cause discomfort.
Sources of soluble NSP
Oats
Pulses (peas, beans, lentils)
Fruit
Vegetables
Function of soluble NSP
Helps to reduce blood cholesterol levels & therefore helps to reduce the risk of coronary heart disease.
Eating too many sugary & starchy carbohydrates may increase your risk of developing obesity. Why?
Excess energy is stored in the body as fat (adipose tissue).
Obesity can increase your risk of developing other health problems later in life, for example…
CHD
Type 2 diabetes
Some cancers
Hypertension (high blood pressure)
Why should most of your energy intake come from starchy carbohydrates?
They provide a steady release of energy, which lasts longer, whereas sugar only provides a ‘quick’ release of energy
Eating too many sugary carbohydrates can increase your risk of developing ….….………… . How?
Tooth decay. Bacteria in your mouth feed on which produces an acid. The sticky mixture of food, bacteria and acid is called plaque. The acid erodes at the tooth enamel, eventually causing tooth decay.
What substance do fizzy drinks contain that also dissolves tooth enamel?
Phosphoric acid
State the equation for the erosion of tooth enamel.
Sugar + bacteria -> acid
List ways in which parents can help reduce the risk of their children developing tooth decay
(i) Limit consumption of sugary foods and drinks between meals
(ii) Replace fizzy drinks with milk or water
(iii) Encourage to brush teeth at least twice a day with fluoride toothpaste
(iv) Bring to regular dental check-ups, at least twice a year
Effects of a deficiency of carbohydrates
[It’s very unlikely for a person to have a deficiency in carbohydrate]
Lack of energy, lethargy (tiredness), weight loss.
