Biology GCSE

Diet and Exercise

• A healthy diet is made from the "right" balance of the different foods you need.
• You are malnourished if your do not eat a balanced diet.
• If you take in more energy that you need you may become fat and develop health problems.
• Your metabolic rate is a measure of how quickly your cells convert food into energy. 

Weight Problems

• Obese people are likely to suffer from arthritis, diabetes, high blood pressure and heart disease.
• Malnourished people have a reuces resistance to infection and irregular periods.

Fast Food

• Cholesterol is made by the liver.
• It is transported by lipoproteins.

LDLs = bad (can cause disease)

HDLs = good

• Saturated fat in you diet increases your level of cholesterol.
• Mono-unsaturated and polyunsaturated fats help reduce the cholesterol levels.
• Statins stop the liver producing too much cholesterol by the body forcing the cells to gather cholesterol form the blood stream.

Animal and Plant Cells

partfunction nucleus contains genetic material, which controls the activities of the cell cytoplasm most chemical processes take place here, controlled by enzymes cell membrane controls the movement of substances into and out of the cell mitochondria most energy is released by respiration here ribosomes protein synthesis happens here

Extra parts of plant cells

partfunction cell wall strengthens the cell chloroplasts contain chlorophyll, which absorbs light energy for photosynthesis permanent vacuole filled with cell sap to help keep the cell turgid