BTEC Applied Science Unit 1 Chemistry

BTEC Applied Science Unit 1 Chemistry Define Oscillation - A regularly repeating motion about central value Define the energy level of an electron. - One of the fixed, allowed, values of energy for an electron that is bound to an atom. Define the term 'action potential - The impulse passed along the axon Define the term 'resting potential - When the neurone is not transmitting an action potential. During this time the K+/Na+ pump is at work Define the term 'synapse' - The small gap in between the axon terminal of one neurone and the dendrite of the next neurone Define the term atomic radius - The distance between the nucleus of an atom and the outermost electron Define the term Avogadro's Constant - The number of atoms in a mole of a given substance. Quoted as 6.02x10^23 Define the term covalent bond - A shared pair of electrons Define the term displacement - When a more reactive element takes the place of a less reactive element in a molecule Define the term ductility - How easily a material can be drawn into wires Define the term electronegativity - A measure of how well an atom attracts a bonding pair of electrons in a covalent bond Define the term exocytosis - The release of the acetylcholine into the synaptic cleft. This then diffuses across the synapse. Define the term first ionisation energy - The energy required to remove the outermost electron from one mole of gaseous atoms to produce one mole of gaseous +1 ions Define the term ionic bond - The electrostatic attraction between oppositely charged ions Define the term malleability - How easily a material can be hammered into shape Define the term oxidation - Oxidation is loss of electrons Define the term oxidising agent - An oxidising agent is something that gains electrons Define the term reducing agent - A reducing agent is something that loses electrons Define the term reduction - Reduction is gain of electrons Define the term relative atomic mass - The average mass of an atom of an element relative to 1/12th the relative atomic mass of Carbon12 Define the term relative molecular mass - The average mass of a molecule relative to 1/12th the relative atomic mass of Carbon12 Describe columnar epithelial tissue - Column shaped ciliated cells and goblet cells held in place by a membrane Describe squamous epithelial tissue - A lining tissue that is only one cell thick. Made from squamous cells that form a smooth, flat layer. Describe the adaptations found in a palisade cell - Closely packed together Chloroplasts Large vacuole Describe the adaptations of a root hair cell - Root hair shape Large vacuole Thin cellulose walls Describe the adaptations of a sperm cell - Undulipodium Lots of mitochondria Shaped head containing acrosome Haploid nucleus Describe the adaptations of egg cells - Contains a haploid nucleus Protective outer layer (zona pellucida) Corona radiata Describe the adaptations of red blood cells - No nucleus (mammals only) Biconcave shape Haemoglobin Flexible Describe the adaptations of white blood cells - Multi-lobed nucleus Enzymes found within the lysosomes Describe the axon - A long single fibre that carries nerve impulses Describe the change in colour as you go down group 7 - They become darker as you go down the group Describe the change in state as you go down group 7 - The trend is they become more solid (i.e. fluorine is a gas, bromine is a liquid and iodine is a solid) Describe the characteristics of fast glycolytic twitch muscle fibres - Few mitochondria and capillaries Less myoglobin Large concentration of glycogen for anaerobic respiration Describe the characteristics of fast oxidative muscle fibres - Similar to slow twitch with many mitochondria, myoglobin and capillaries Hydrolyse ATP faster to contract more quickly Describe the characteristics of slow twitch muscle fibres - Less sarcoplasmic reticulum (specialised ER) More mitochondria More myoglobin A dense capillary network Describe the dendrites - Highly branched fibres that conduct impulses Describe the differences between myelinated and non-myelinated cells - Myelinated cells are longer and can transmit impulses faster down the axon Describe the function of the amyoplasts - Stores starch and converts starch back into glucose when the plant needs energy Describe the function of the cell wall - Provides rigidity and protection to the cell Describe the function of the chloroplasts - Site of photosynthesis as they contain chlorophyll Describe the function of the cytoplasm - Where all of the chemical reactions occur