d) Movement of substances into and out of cells: 2.12 understand definitions of diffusion, osmosis and active transport Diffusion: the net movement of particles from an area of higher concentration to an area of lower concentration Osmosis: the net movement of water molecules across a partially permeable membrane, from a region of high water concentration (low solute concentration) to a region of lower water concentration (high solute concentration) Active transport: movement of substances against a concentration gradient, using energy from respiration. 2.13 understand that movement of substances into and out of cells can be by diffusion, osmosis and active transport. 2.14 understand the importance in plants of turgid cells as a means of support - TRIPLE SCIENCE ONLY: When plants are well watered, the cells take in water by osmosis and the cells become turgid (the contents of the cell push against the cell wall). This helps to support the plant. When there's not enough ...
c) Biological Molecules 2.5 identify the chemical elements present in carbohydrates proteins and lipids (fats and oils) Carbohydrates: Carbon Hydrogen Oxygen Proteins: Carbon Hydrogen Oxygen Nitrogen Lipids: Carbon Hydrogen Oxygen 2.6 describe the structure of carbohydrates, proteins and lipids as large molecules made up from smaller basic units Carbohydrates: large molecules (eg. starch and glycogen) are made from simple sugars (eg. glucose) Proteins: large molecules are made up of amino acids Lipids: large molecules are made up of fatty acids and glycerol 2.7 describe the tests for glucose and starch Test for glucose/reducing sugar: Add Benedict's reagent to the sample of food Heat it (with out boiling) in a water bath If glucose is present it will form a coloured precipitate Test for starch: Add iodine solution to the sample If starch is present it will turn from an orange / brown colour to a blue /black colour 2.8 understand the role of enzymes ...