Cell Biology Summary

• Nucleus: Controls cell activities, contains DNA. Found in Plant, animal and fungal cells.
• Cell Wall: Gives the cell a rigid structure. Found in plant, fungus and bacterial cells.
• Cell Membrane: Controls the movement of substances into and out of the cell. Found in all cell types.
• Chloroplasts 


  Site of photosynthesis. Found only in plant cells.
• Vacuole: Stores cell sap, helps control water balance. Found in plant and fungal cells.
• Mitochondria: Site of aerobic respiration. Found in plant, animal, and fungal cells.
• Plasmid: Ring of DNA that can be removed in genetic engineering. Found only in bacterial cells.
• Ribosome: Site of protein synthesis. Found in all cell types.
• Diffusion: Movement of molecules from an area of higher concentration to an area of lower concentration (down a concentration gradient.)
• Plasmolysed: the condition of a plant cell that has lost so much water that its cytoplasm shrinks and pulls the cell membrane away from the cell wall.
• Turgid 


  Swollen
• active transport: Energy-requiring process that moves molecules across a cell membrane against a concentration gradient
• DNA: A complex molecule containing the genetic information that makes up the chromosomes.
• DNA bases

  Adenine, Thymine, Guanine, Cytosine
• Protein synthesis: Forming proteins based on information in DNA and carried out by RNA (from the nucleus to the ribosomes.)
• Proteins 


  Sequences of amino acids
• Hormones: Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another
• Enzymes: Catalysts for chemical reactions in living things. Are unchanged in the process
• Specificity 


  Enzymes will only work with certain substrates
• Substrate 


  A specific reactant acted upon by an enzyme
• Active site of an enzyme: the region of an enzyme that attaches to a substrate. Shaped specifically to fit its specific substrate.
• mRNA: messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome
• synthesis reaction: a reaction in which two or more substances combine to form a new product
• degredation reaction: a reaction in which one substance is broken down to form two products
• optimum conditions: the temperature and pH where enzyme activity is highest
• Denaturation: loss of normal shape of a protein due to heat or other factor
• Genetic engineering: The direct manipulation of genes for practical purposes.
• Respiration: The process by which cells break down molecules to release the energy they contain.
• Muscle cell contraction: A nerve ending releases ACh which causes the stimulation of a muscle fiber.
• Fermentation word equation (Plant): Glucose -> carbon dioxide + ethanol + energy
• Lactate: a 3-carbon compound produced from pyruvate during anaerobic metabolism. Causes muscle fatigue in animals.