Unit 2: The Cell
Nucleus: Stores DNA for the cell.
Eukaryotic cell: Has a nucleus.
Prokaryotic cell: No nucleus.
Light microscope: uses lenses for focus.
Electron microscope: Creates beam of electrons for focus. It can be scanning, or transmission.
Cell fractionation: Taking a cell apart to study it.
Organelle: Organ for a cell.
Mitochondrion: A organelle that makes ATP (a kind of chemical energy) for the cell. Has it's own DNA.
Chloroplast: organelle in plant cells. Used for photosynthesis. Has it's own DNA.
Rough endoplasmic reticulum: Organelle in a cell. Has lots of ribosomes on it's surface, so it appears rough when looking at it through a microscope. Creates secretory proteins and membranes.
Smooth endoplasmic reticulum: Organelle in a cell. Does not have ribosomes on it surface, so it appears smooth when looking at it through a microscope. Used for metabolic processes.
Lysosome: Used to hydrolyse macromolecules.
Vesicle: Transporter in the cell.
peroxisomes: Creates toxic hydrogen peroxide away from the rest of the cell. Fortunately it can also turn hydrogen peroxide back into water.
Cytoskeleton: skeleton for the cell. Also used in cell motility when it interacts with motor proteins.
Cell wall: Extracellular structure of plant cells.
Cytoplasm: Area of cell outside the nucleus.
Ribosome: Cellular components that carry out protein synthesis.
Golgi apparatus: Ships and stores products of the endoplasmic reticulum out into the cell.
Cristae: Fold in mitochondria
Nucleolus: Mass of densely stained granules and fibres adjoining part of the chromatin.
Membrane structure and function:
Diffusion: Substances move to areas with less concentration of itself.
Concentration gradient: The gradient of the concentration of a substance.
Integral proteins: Penetrate the hydrophobic interior of the lipid bilayer.
Peripheral proteins: Not embedded in the lipid bilayer. loosely bound to the membrane.
Transport protein: Protein in the membrane that moves substances out of the cell.
Osmosis: When water moves down its concentration gradient.
Osmoregulation: When a cell regulates water flowing in and out of itself.
Facilitated diffusion: when a substance is assisted in moving down its concentration gradient.
Active transport: When a substance is moved against its concentration gradient.
Electrochemical gradient: A substance's concentration gradient plus some electrical forces control the movement of the substance.
Cotransport: A transport protein that uses the diffusion of one substance to power the active transport of another.
Exocytosis: The bulk transport of a large molecule from in the cell to out of the cell. A vesicle carries the molecule and then merges with the membrane. Releasing the molecule outside of the cell.
Endocytosis: When a pocket forms in the membrane to capture a substance and bring it back into the ell by turning into a vesicle. There are 3 types of endocytosis.
Phagocytosis: A type of endocytosis. Where a cell "eats" a substance by engulfing it with pseudopodia.
Pinocytosis: A type of endocytosis. Where a cell "drinks" substances by engulfing any substance it can capture.
Receptor mediated endocytosis: A type of endocytosis. Where a cell "drinks" a specific substance by using receptors by the substance, and then engulfing those receptors.
Metabolism
Metabolic pathway: A series of reactions that turn a starting molecule into an end product.
Catabolic pathway: A metabolic pathway that releases energy by turning a starting molecule into a simpler one.
Anabolic pathway: A metabolic pathway that consumes energy to turn a starting molecule into a more complex one.
Kinetic energy: Energy associated with the relative movement of objects.
Thermal energy: Energy relating to the random movement of atoms and molecules.
Heat: Thermal energy in transport from one object to another.
Potential energy: The potential for energy that matter posses because of its location or structure.
Chemical energy: Type of potential energy that can be released in a chemical reaction.
First law of thermodynamics: Energy can never be created or destroyed.
Second law of thermodynamics: Every energy transfer or transformation causes an increase of entropy in the universe.
Exergonic reaction: Reaction that releases energy into its surroundings.
Endergonic reaction: Reaction that absorbs energy from its surroundings.
Enzyme: Macromolecule that acts as a catalyst.
Substrate: The reactant an enzyme acts on.
Active site: Site on an enzyme that a substrate binds with.
Competitive inhibitor: Reduces an enzyme's function by blocking its active site.
Non-competitive inhibitor: Reduces an enzyme's function by biding to a site that is not an active site.
Allosteric regulation: When a protein's function at one site is affected by a change at another site.
Allosteric activation and inhibition: A protein oscillates between an active and inactive state. And activator molecule stabilises the protein in its active state. Where as an inhibitor molecule stabilises the protein in its inactive state.
Cooperative activation: When the binding of a substrate to a protein makes it easier for future substrates to bind to that protein.
Cellular Respiration
Oxidation: Loss of electrons.
Reduction: Gaining electrons. Yes, really: gaining.
Reducing agent: Substance that gives another an electron.
Oxidation agent: Substance that receives an electron.