1. Year 9 Science PPE Preparation Keywords Biology Words Biology Definitions Photosynthesis Carbon dioxide + water  glucose + oxygen Mass number The number of protons and neutrons in an atom. CellThe basic unit of lifeActive transport Moving substances up a concertation gradient. Requires energy. Acids React with oxides, hydroxides and carbonates in neutralisation reactions. Bacteria An organism containing no nucleus, some have flagella. Transpiration The process of water leaving a leaf by diffusion through the stomata. Group 1 metal Alkali metals which react violently with water. Light microscope Used to magnify an image using lenses and a beam of light. Diffusion The movement of molecules from high concentration to low concentration. ExtractionRemoving a metal from its ore. Electron microscope Used to magnify an image using lenses and a beam of electrons. Osmosis The movement of water from high water potential to low water potential, through a partially permeable membrane. Physics Words Physics Definitions Function The job a structure or item does. XylemCarries water and minerals up a plant Potential Difference The difference in energy carried by electrons before and after they travel through a component. Also called voltage. NucleusContains the DNAPhloemCarries sucrose up and down a plant.Current The flow of electrons round a circuit. Chloroplast Carries out photosynthesis. Found in plant cells. Root hair cell Found in roots, absorbs water and minerals. Resistance How easy or difficult it is for a current to flow through a circuit. Mitochondria Carries out respiration. Found in plants and animal cells. Chemistry Words Chemistry Definitions Line of best fit A straight or curved line which closely fits the data. Cell membrane Controls what moves in and out of the cell. In all cell types. Element A substance made up of one type of atom VelocitySpeed in a certain direction. EnzymeBiological catalyst.Melting point The point at which a substance changes state from solid to liquid AccelerationThe change in velocity over time. Catalyst Speeds up chemical reactions without being used up. Boiling point The point at which a substance changes state from liquid to gas VolumeThe space taken up by an object. Communicable disease A disease which can be spread between people. Physical State The arrangement of particles in a substance. Can be solid, liquid or gas. Density The amount of mass of a substance contained within a volume. BMI A measure of your mass compared to your height. AtomThe smallest unit of matter.Extension The stretch of an object when pulled by a mass. Glucose The molecule use din respiration. It is produced in photosynthesis Electrons Part of an atom. Found on the electron shell. Has a negative charge. Energy Measured in joules. Can be transferred but not created or destroyed. Physics Topics Springs, Electrical Current, Kinetic Theory, Motion, Fields Which Subjects Do I need to revise? ClassTopics to Revise Mr Cresswell, Mr Fleetwood, Miss Orrell, Mr Barenskie Biology and Chemistry Mr Thomas, Mr Reynolds, Mr Hotchin, Mr Youlden Chemistry and Physics Miss Pitt, Miss Scott, Miss Allwood Physics and Biology Balancing Equations Make sure the number of elements is the same for the products and reactants. Remember that compounds cannot be split up. Chemistry topics Atomic Structure, States of matter, Metals, Acids Biology Topics Cells, Enzymes, Transport in plants, Health and disease