Organisation - Topic 2 (paper 1)

• Amylase: An enzyme produced in the salivary glands and pancreas that breaks carbohydrates down into simple sugars
• Aorta: The main artery that takes oxygenated blood away from the heart to the body
• Artery: A blood vessel that carries blood at high pressure away from the heart
• Benign tumour: An abnormal cell growth that is contained within one area and does not invade other areas of the body
• Bile: A substance made in the liver and stored in the gallbladder which is used to neutralise stomach acid in the intestine and emulsify fats
• Blood: A tissue containing red blood cells, white blood cells, platelets and plasma
• Cancer: A non-communicable disease caused by changes in the cell that lead to uncontrolled growth and division
• Capillary: A very thin blood vessel that is used for exchange of substances
• Cell: The basic building block of all living organisms
• Communicable disease: A disease that can be spread between individuals either directly or indirectly
• Coronary heart disease: A disease caused by the buildup of fatty deposits inside the coronary artery, narrowing it and reducing blood flow to the heart tissue
• Enzymes: Biological catalysts that increase the rate of reactions in living organisms
• Health: The state of physical and mental wellbeing
• Heart: An organ that pumps blood around the body in a double circulatory system
• Cells make up all living things.
• A tissue is a group of specialised cells with a similar structure and function.
• Organs are formed from a number of different tissues, working together to produce a specific function.
• Organs are organised into organ systems, which work together to perform a certain function.
• The digestive system is an organ system, as it is made up of organs working together to perform a certain function.
• The food you eat is large and insoluble and needs to be broken down in order for it to be in a form that can be absorbed by cells.
• The digestive system is made up of the following organs: Glands (salivary glands and the pancreas) which produce digestive juices containing enzymes which break down food, The stomach produces hydrochloric acid to kill bacteria and to provide the optimum pH for the protease enzyme to work, The small intestine is where soluble molecules are absorbed into the blood, The liver produces bile which is stored in the gall bladder, which helps with the digestion of lipids, The large intestine absorbs water from undigested food to produce faeces.
• Enzymes are biological catalysts, a substance that increases the rate of reaction without being used up.
• Enzymes are present in many reactions so that they can be controlled.
• Enzymes can both break up large molecules and join small ones.
• Enzymes are protein molecules and the shape of the enzyme is vital to its function.
• Each enzyme has its own uniquely shaped active site where the substrate binds.
• The Lock and Key Hypothesis is a simplified explanation of how enzymes work: The shape of the substrate is complementary to the shape of the active site, so when they bond it forms an enzyme-substrate complex.
• Once bound, the reaction the reaction takes place and the products are released from the surface of the enzyme.
• Enzymes require an optimum pH and temperature, because they are proteins.
• The optimum temperature for most enzymes is a range around 37 degrees celsius (body temperature).
• The rate of reaction increases with an increase in temperature up to this optimum, but above this temperature it rapidly decreases and eventually the reaction stops.
• When the temperature becomes too hot, the bonds in the structure will break, changing the shape of the active site, so the substrate can no longer fit in.
• There are a number of types of white blood cells: those that produce antibodies against microorganisms, those that engulf and digest pathogens, and those that produce antitoxins to neutralise toxins produced by microorganisms.
• The walls of the alveoli are very thin, meaning there is a short diffusion pathway.
• The clot dries and hardens to form a scab, which allows new skin to grow underneath while preventing microorganisms from entering.
• Plasma is liquid that carries the components in the blood: red blood cells, white blood cells, platelets, glucose, amino acids, carbon dioxide, urea, hormones, proteins, antibodies and antitoxins.
• Oxygen diffuses down its concentration gradient into the capillary bloodstream, which has a low concentration of oxygen.
• Solutions to coronary heart disease include stents, which keep the arteries open to allow blood to flow through, and statins, which reduce the risk of strokes, coronary heart disease and heart attacks.
• The enzyme is said to be denatured and can no longer work.
• Blood is made up of plasma, red blood cells, white blood cells and platelets.