b2-organisation

• an organ system is a group of organs working together to perform a particular function
• a tissue can include more than one cell type
• enzymes increase the rate of a reaction and act as a biological catalyst
• the active site of an enzyme is the part of the enzyme a substrate fits into
• protein is broken down into amino acids
• benedict's solutions tests for sugar and requires a water bath
• iodine tests for carbohydrates
• ethanol tests for fats
• biuret tests for protein
• biuret turns pink/purple if protein is present
• ethanol emulsifies if fat is present
• iodine goes blue/black if starch is present
• benedict's is blue when there is no sugar, green if there is a trace, yellow if its low, orange if it's moderate and red if there's a high amount
• gas exchange occurs in the alveoli in the lungs
• the right side of the heart pumps deoxygenated blood to the lungs
• the vena cava carries blood into the right atrium
• white blood cell help protect and defend the body against infection
• plasma is the liquid that carries everything in the blood
• a stent is a tube that is inserted inside an artery
• stents keep coronary arteries open, so oxygenated blood can flow to the heart muscle
• risks of stents are: infection, complications during surgery, a risk of patients developing thrombosis (blood clot) near the stent
• health is a state of physical and mental well-being
• communicable diseases can spread between people, or between animals and people
• non-communicable diseases include: asthma, cancer and coronary heart disease
• carcinogen is something that causes cancer
• the liver and the brain are effected by drinking too much alcohol
• a tumour is a mass of cells
• tumours form as a result of cellular changes which lead to uncontrolled cell growth and division
• benign tumours are not cancerous
• malignant tumours are cancerous
• stomata in the lower epidermis of a leaf allow carbon dioxide to diffuse directly into the leaf
• the spongy mesophyll has large air spaces to allow gases to diffuse in and out of cells
• translocation is the movement of food molecules through phloem tissue
• water is most commonly lost at the plants leaves to the environment
• lignin is the strengthening material present in the walls of the xylem tissue
• guard cells control the opening and closing of the stomata
• at higher temperature there is an increase in rate of transpiration as the water molecules have more energy to evaporate and diffuse out of the stomata