Glossary

• Affinity = an attraction between molecules that results in the formation of a new molecule
• Bohr shift = movement of the oxygen dissociation curve to the right of the normal
• Carbon dioxide = colourless, odourless gas found in the atmosphere with chemical formula CO2
• Loading/associating = oxygen binding to iron in the haem group at areas of higher oxygen concentration
• Oxygen dissociation curve = curve that plots the proportion of haemoglobin in its saturated form against the partial pressure of oxygen
• Partial pressure = gas exerting pressure in a container filled with more than one gas
• Percentage saturation = percent of haemoglobin present that is saturated with oxygen
• Positive cooperativity = if the first binding event increases the affinity of the second site
• Primary structure = sequence of amino acids in a polypeptide
• Quaternary structure = more than one polypeptide chain joining together to form a more complex molecule
• Secondary structure = polypeptide chain folding into alpha helices or beta-pleated sheets held together by hydrogen bonds
• Tertiary structure = polypeptide chain folding again into a 3D shape forming hydrogen bonds, ionic bonds and disulphide bridges
• Unloading/dissociating = process by which haemoglobin releases its oxygen
• Adhesion = tendency of particles to cling together to one another
• Antioxidants = compounds that inhibit oxidation, a chemical reaction that can produce free radicals
• Aorta = largest artery of the body, carries blood from the heart to the body
• Atrioventricular node = electrical gatekeeper between atria and ventricles
• Atrioventricular valves = valves that connect the atrium to the ventricles preventing backflow
• Atrium = top chambers of the heart that receives blood from the body and pumps it into the ventricles
• Bundle of His = specialised muscle bundle connecting the atrial and ventricular chambers of the heart
• Cardiac cycle = series of pressure changes that take place within the heart from and start to the end of a heartbeat
• Cardiac output = quantity of blood pumped by the heart in a given time period
• Cohesion = tendency of water molecules to stick together
• Cohesion-tension theory = water molecules form hydrogen bonds causing them to stick together, creating surface tension
• Coronary arteries = arteries that supply blood to the heart
• Diastole = phase of the heartbeat when the heart muscle relaxes and allows the chambers to fill with blood
• Endothelium = monolayer of endothelial cells on the inner cellular lining of the blood vessels and lymphatic system
• Heart rate = frequency of heartbeat measured by the number of contractions per minute
• Hydrostatic pressure = pressure exerted by a fluid at equilibrium at a given point within the fluid due to gravity
• Mass flow theory = theory that explains the movement of water and solutes from high to low concentration across a partially permeable membrane
• Metabolism = set of life-sustaining chemical reactions in organisms
• Myocardial infarction = heart attack -> when one or more areas of the heart muscle don't get enough oxygen
• Myogenic = originating in muscle tissue rather than from nerve impulses
• Phloem = vascular tissue in plants which conducts sugars and other metabolic products from the leaves to the rest of the plant
• Pocket valves = valves found in veins preventing backflow of blood
• Pulmonary artery = carries blood from the heart to the lungs
• Pulmonary vein = carries oxygenated blood from the lungs to the left atrium
• Semi-lunar valves = valves separating the arteries and the ventricles
• Sieve tube elements = specialised cells that are important for the function of phloem
• Sinoatrial node = generates an electrical signal that causes the upper chambers of the heart to contract