Science Biology 1

• Osmosis is the net movement of water molecules from an area of high water concentration (or potential) to an area of low water concentration (or potential) through a partially permeable membrane.
• Osmosis is always over a partially permeable membrane.
• Water will move left to right in osmosis.
• The sugar molecules are too big to move across the membrane in osmosis.
• Algae are classified as Protista and are eukaryotes with a nucleus.
• Some cells don't have a nucleus, and there are two types of cells that can be recognised on the basis of their structure: prokaryotic cells and eukaryotic cells.
• Prokaryotes are bacteria and cyanobacteria, which are found in Protista, Fungi, Plants, and Animals.
• Eukaryotes have their DNA in a nucleus, while prokaryotes have free DNA (not in a nucleus).
• A prokaryote is a single-celled organism that lacks a membrane-bound nucleus.
• Prokaryotes are the first animals to have evolved.
• Plasmids are extra bits of DNA that code for specific features like antibiotic resistance, and bacteria can share these by passing them between each other.
• Plasmids vary in size but generally range from 3-4 µm.
• A eukaryote, in this case a fungus, has a cell membrane, nucleus, plasmids, chloroplasts, cell wall, and cytoplasm.
• A virus is not considered a cell or a living organism.
• Cells can be very small, such as 100 nanometers, or very large, such as 100 micrometers.
• Cells can be measured in standard form, for example, 10,000 = 1 x 10^4, 1,000 = 1 x 10^3, 100 = 1 x 10^2, 0.0001 = 1 x 10^-4, 0.001 = 1 x 10^-3, 0.01 = 1 x 10^-2.
• The nucleus and mitochondria of a cell are so important because the nucleus contains genetic information which controls activities of the cells and controls protein production, and mitochondria do aerobic respiration, releasing energy for all the processes of the cell.
• The functions of the nucleus, ribosomes and mitochondria are all linked because the nucleus contains DNA which codes for proteins, proteins are made at the ribosomes, and mitochondria provide energy for protein synthesis.
• Cell membranes are vital because they allow compartmentalisation, keeping molecules separate from other molecules.
• Animal Cell, Plant/Algal Cell, Bacterial Cell, Yeast Cell, Eukaryotic or prokaryotic?
• Active transport is the movement of substances from a dilute solution to a more concentrated solution against a concentration gradient, requiring energy from respiration.
• Algae are simple aquatic organisms (protista) that make their own food by photosynthesis.
• Alveoli are tiny air sacs in the lungs that increase the surface area for gaseous exchange.
• Bacteria are single-celled prokaryotic organisms.
• The cell membrane is the membrane around the contents of a cell that controls what moves in and out of the cell.
• The cell wall is the rigid structure around plant and algal cells, made of cellulose and strengthens the cell.
• Cellulose is the complex carbohydrate that makes up plant and algal cell walls and gives them strength.
• Chlorophyll is the green pigment contained in the chloroplasts.
• Chloroplasts are the organelles in which photosynthesis takes place.
• Cytoplasm is the water-based gel in which the organelles of all living cells are suspended and most of the chemical reactions of life take place.
• Diffusion is the spreading out of the particles of any substance in a solution, or particles in a gas, resulting in a net movement of particles from an area of higher concentration to an area of lower concentration down a concentration gradient.
• Eukaryotic cells are cells from eukaryotes that have a cell membrane, cytoplasm, and genetic material enclosed in a nucleus.
• Hypertonic (osmosis) is a solution that is more concentrated than the cell contents.
• Hypotonic (osmosis) is a solution that is less concentrated than the cell contents.
• Isotonic (osmosis) is a solution that is the same concentration as the cell contents.
• Mitochondria are the site of aerobic cellular respiration in a cell.
• The nucleus is an organelle found in many living cells containing the genetic information surrounded by the nuclear membrane.
• Osmosis is the diffusion of water through a partially permeable membrane from a dilute solution (which has a high concentration of water) to a concentrated solution (with a low concentration of water) down a concentration gradient.
• A partially permeable membrane is a membrane that allows only certain substances to pass through.
• A permanent vacuole is a space in the cytoplasm filled with cell sap.