Biology option A.2 (energy in human diets)

HideShow resource information
Comparison of energy in protein, carbohydrates and fats
Protein: 1720kj/100g, carbohydrates: 1760kj/100g, fat: 4000kg/100g. This is because energy is mainly stored in the bonds between carbon and hydrogen, and less in bonds between carbon and oxygen. Lipids have a high C-H:C-O ratio compared to proteins
1 of 8
Consequences of excessive carbohydrates
carbs are broken down into monosaccharides for transport in the blood. If the energy is not used, the excess carbs are converted to glycogen and fat, leading to obesity. Sustained high intake leads to development ofdiabetes
2 of 8
Consequences of excessive fats
Excessive fat intake is strongly correlated to increase in blood pressure, atherosclerosis and coronary heart disease. Plaque develops, increases blood pressure and potentially clotting in arteries.
3 of 8
Consequences of excessive proteins
There is mechanism to store excess protein. which is broken down by deamination in the liver and the waste product is excreted by kidneys, which use calcium to break down urea, if there is not enough, they draw from the bones, causing brittle bones
4 of 8
Appetite control centre in the brain
The hypothalamus takes messages from hormones: Leptin from fat (adipose) tissue, insulin from the pancreas and CCK from the small intestine and uses this to judge hunger and appetite.
5 of 8
BMI formula and values for underweight, normal weight, overweight and obese
formula: mass(kg)/height (m)^2, underweight: below 18.5, normal weight: 18.5-24.9, overweight: 25-29.9, obese: above 30.0
6 of 8
Reasons for increasing rates of obesity
1. Change in types (more fat) and quantities (supersizing) of food which people eat. 2. Decreased energy expenditure, advances in technology have reduced level of physical activity in many occupations
7 of 8
Consequences of anorexia nervosa
Malnutrition, hormonal imbalance, skin problems, anaemia, immune disorders, low blood pressure. Often caused by fear of gaining body mass due to cultural pressure
8 of 8

Other cards in this set

Card 2

Front

Consequences of excessive carbohydrates

Back

carbs are broken down into monosaccharides for transport in the blood. If the energy is not used, the excess carbs are converted to glycogen and fat, leading to obesity. Sustained high intake leads to development ofdiabetes

Card 3

Front

Consequences of excessive fats

Back

Preview of the front of card 3

Card 4

Front

Consequences of excessive proteins

Back

Preview of the front of card 4

Card 5

Front

Appetite control centre in the brain

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Biology option 1 (energy in human diets) resources »