organisation

• communicable

  refers to a disease that can be passed from person to person
• non-communicable

  refers to a disease that cannot be passed from person to person
• risk factor

  a factor that will increase the chance of developing a disease
• casual mechanism

  a factor that makes a disease more likely to occur and the reason for this is known
• coronary heart disease (CHD)


  a condition caused by a build up of fatty deposits in the coronary arteries, leading to a lack of blood and oxygen to the heart muscle
• stent 


  a tube that is inserted into a blood vessel to keep it open
• statins

  a drug used to help lower cholesterol levels in the blood
• tumours

  groups of cancerous cells
• benign


  a tumour that will not spread to other parts of the body
• malignant 


  a tumour that can spread to other areas of the body
• epidermis 


  covers the outer surfaces of the plant for protection
• palisade mesophyll

  the main site of photosynthesis in the leaf
• spongy mesophyll

  air spaces between the cells allow gases to diffuse through the leaf
• xylem vessels

  transport water and minerals through the plant, from roots to leaves, also support the plant
• phloem vessels

  transport dissolved food materials through the plant such as sugar
• meristem tissues

  found mainly at the tips of the roots and shoots, where it can produce new cells for growth
• catalyst 


  a substance that increases the rate of a chemical reaction without being changed or used itself
• active site 


  area on an enzyme that a substrate molecules can fit into
• optimum 


  the conditions at which an enzyme works best
• lock and key theory 


  a model used to explain how enzymes work, where the active site is the lock and the substrate is the key
• denature


  when the shape of an enzyme is changed ( by excessive temperature or pH) so it no longer functions
• protease

  an enzyme used to break down proteins and amino acids
• lipase

  an enzyme that breaks down fat into fatty acids and glycerol
• carbohydrase

  an enzyme that can break down a carbohydrate
• amylase

  an enzyme that breaks down starch
• bile

  a fluid, produced by the liver, that emulsifies fat
• specialised

  adapted for a particular purpose
• tissue

  a group of cells that have a similar structure and function
• organ

  a group of tissues gathered together to perform a particular function
• organ system

  a group of organs hat all perform related functions
• plasma

  clear fluid part of the blood containing dissolved substances
• haemoglobin

  pigment in red blood cells that carries oxygen to the organs
• double circulatory system

  the type of blood system found in mammals, where the blood goes through the heart twice on each circuit of the body
• atria

  the upper two chambers of the heart
• ventricles

  the lower two chambers of the heart
• pacemaker

  a natural or artificial device that controls heart rate
• pulmonary artery

  carries de-oxygenated blood from the heart to the lungs
• trachea

  the main tube or windpipe taking air from the mouth to the lungs
• bronchi

  two tubes branching from the trachea into each lung
• alveoli

  air sacs in the lungs