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72 Cards in this Set
- Front
- Back
Monomer |
Oneof many small molecules that combine to form a larger one.
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Polymer |
A large molecule made up of many similar monomer units covalently bonded together. |
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Metabolism |
The sum total of all the biochemical reactions taking place in the cells of an organism. |
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Condensation reaction |
When two small molecules join to form a larger molecule when a covalent bond forms and water is released. |
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Hydrolysis reaction |
When a large molecule is broken down into smaller ones by the breaking of a covalent bond using water. Enzymes do this to help break down molecules |
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Glycosidic bond |
A covalent bond which forms in a disaccharide or monosaccharide in a condensation reaction. C-O-C |
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Peptide bond |
The bond between 2 amino acids in a protein, formed by a condensation reaction. C-N |
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Polypeptide |
A long chain of amino acids joined by covalent bonds |
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Hydrogen bonds |
Weak bonds between oxygen and hydrogen holding the secondary structure of a protein in a coil |
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Activation energy |
The minimum amount of energy required to start a reaction |
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Active site |
A region on an enzyme where the substrate fits |
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Substrate |
The molecule on which an enzyme acts |
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Enzyme-substrate complex |
Formed when an enzyme and a substrate fit together and form temporary bonds |
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Denaturation |
Permanent changes in the structure of a protein. The enzyme's active site changes shape so the substrate no longer fits |
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Enzyme |
Molecule that binds to a substrate. They're biological catalysts which lower activation energy, allowing the reaction to occur quicker at lower temperatures. |
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Competitive inhibitor |
Molecule that binds to the active site of an enzyme |
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Non-competitive inhibitor |
Molecule that binds to an enzyme at any position other than the active site |
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Resolution |
The degree to which it is possible to distinguish between 2 objects that are very close together. The higher the resolution, the greater the detail. |
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Magnification |
The degree to which the size of an image is larger than the object itself |
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Cell fractionation |
The process by which cells are broken up and the organelles separated out
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Prokaryotic cells |
Cells which lack a nucleus and any membrane bond organelles |
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Eukaryotic cells |
Cells with a distinct nucleus and possess membrane bound organelles |
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Amino acids |
Monomer units of proteins |
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Saturated triglyceride |
A triglyceride where the fatty acid contains no C=C double bonds |
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Mono-unsaturated triglyceride |
A triglyceride where the fatty acid only contains 1 C=C double bond |
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Poly-unsaturated triglyceride |
A triglyceride where the fatty acid contains more than one C=C double bond |
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Hydrophillic |
Attracted to water |
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Hydrophobic |
Repelled by water, attracted to fat |
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Tissue |
A collection of similar cells that work together to perform a specific function. |
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Organ |
A group of tissues which work together to perform a variety of functions |
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Organ system |
A group of organs working together as a single unit |
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Starch |
Storage molecule in plants which is coiled, insoluble and can be hydrolysed to form alpha glucose |
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Glycogen |
Storage molecule in animals which has short chains so it can be readily hydrolysed into alpha glucose for respiration. |
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Cellulose |
Parallel chains of beta glucose with each rotated 180 degrees to the next. The chains are joined by hydrogen bonds to form micro fibrils for strength |
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Fluid-mosaic model |
The structure of a cell surface membrane. The phospholipids aren't bonded together and move around each other. The proteins are arranged like mosaics within the phospholipid bilayer. |
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Extrinsic proteins |
Proteins on the surface of the bilayer |
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Intrinsic proteins |
Proteins spanning the bilayer |
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Chloroplasts |
Organelle in plant cells containing grana, thylakoids and stroma. Photosynthesis occurs here. |
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Semi-conservative replication |
The way DNA makes exact copies of itself by unwinding the double helix. Each chain acts as a template for the new strands. |
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Mitosis |
Cell division where 2 diploid daughter cells are produced |
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Haploid |
Cells have half the number of chromosomes of the parent cell |
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Diploid |
Cells have a full set of chromsomes |
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Prophase |
Chromosomes become visible and the nuclear envelope disappears |
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Metaphase |
Chromosomes align along the equator of the cell |
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Anaphase |
Sister chromatids move to opposite poles of the cell |
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Telophase |
Nuclear envelope reforms |
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Cell cycle |
A cell's regular cycle of division, followed by periods of growth |
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Cell differentiation |
Cells become specialised in their structure to suit their roles |
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Diffusion |
The movement of substances from an area of high concentration to an area of low concentration, down a concentration gradient across the partially permeable plasma membrane via the phospholipid bilayer. |
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Facilitated diffusion |
The movement of substances from an area of high concentration to an area of low concentration, down a concentration gradient across the partially permeable plasma membrane via carrier or channel proteins |
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Osmosis |
Movement of water from an area of high water potential to an area of low water potential, down a water potential gradient through a partially permeable plasma membrane across the phospholipid bilayer or via aquaporins |
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Active transport |
The movement of large or water soluble substances across the partially permeable plasma membrane via carrier proteins from an area of low concentration to an area of high concentration |
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Digestion |
Physical and chemical break down of food |
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Assimilation |
Incorporating broken down molecules into body tissues/using them in processes |
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Non-specific defenses |
Mechanisms that don't distinguish between different pathogens e.g. skin |
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Specific defenses |
Mechanisms that do distinguish between different pathogens e.g. lymphocytes |
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Phagocytosis |
Where pathogens are engulfed into vesicles called phagosomes and broken down by enzymes. |
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Antigens |
Molecules, usually proteins, on a cell's surface that, if recognised as non-self, triggers an immune response. |
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Cell-mediated immunity |
T lymphocytes recognise antigen-presenting cells that have been invaded and undergo mitosis to respond |
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Humoural immunity |
Immunity involving B cells and antibodies |
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Antigenic variability |
Viruses, such as flu, have many different strains with different antigens on them |
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Antibodies |
Proteins synthesised by B cells, consisting of heavy and light chains and variable and constant regions |
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Antigen-antibody complex |
Formed when antigens bind to a specific site on the antibody |
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Complementary shape |
Antigens have a shape that means they fit into their specific antibody |
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Monoclonal antibodies |
Isolation and cloning of a single type of antibody |
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Passive immunity |
The introduction of antibodies into individuals from an outside source. |
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Active immunity |
The immune system produces its own antibodies after being stimulated by an antigen |
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Vaccination |
Deliberate exposure to harmless antigenic material in order to activate the immune response and production of memory cells which provides immunity |
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Herd immunity |
Vaccinating most of a population to protect them and reduce the occurrence of the disease. Transmission is decreased. |
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Primary defences |
Mechanisms to prevent the pathogen entering the body |
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Agglutination
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Where antibody-antigen complexes are forms holding the pathogens together in large clumps and immobilising them |
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Neutralisation |
Antigens which are toxins are rendered harmless if they are blocked by being bound to an antibody |