module 2

• eye piece graticule


  glass disc fitted into the eyepiece of the microscope, marked with a fine 0-100
• stage micrometer


  a microscope slide finely divided scale marked on surface. It uses true length which is then used for the calibration of optical systems with eye piece graticule.
• fixing (stages of staining)


  chemicals used to preserve specimens or as near to natural state
• sectioning (stages of staining)

  specimens dehydrated with alcohol them placed in mould with wax/resin to harden so they then can be sectioned with a microtome
• staining (stages of staining)

  specimens treated with stains to show different structures and to increase contrast between organelles
• mounting 


  specimens secured to slide and cover slip is placed on top
• magnification


  how many times larger the image is than the actual size of the object being viewed
• resolution


  determining the amount of detail that can be seen, the ability to see individual objects as separate entities
• microfilaments (in cytoskeleton) 


  contractile fibres formed from protein actin
• microtubules (in cytoskeleton)


  tubular proteins polymerise to form tubes
• prokaryote


  simple, single-celled organism that lacks a nucleus or any other membrane-bound organelle
• eukaryote


  cell that has a membrane-bound nucleus and other compartments/sacks (organelle)
• biochemistry


  reactions involving biological molecules
• catabolic reactions 


  turning large molecules into smaller molecules, reactions which release energy (e.g. respiration)
• anabolic reactions


  turning small molecules into large molecules, reactions which require energy (e.g. protein synthesis)
• hydrogen bond


  a weak intermolecular force formed when a hydrogen atom is covalently bonded to an oxygen/nitrogen bond
• polar covalent bond


  this is when the electrons in a covalent bond are not shared equally, resulting separation of charge gives one end in a slightly negative charge and the term a slightly positive charge
• condensation reaction


  a reaction between 2 molecules resulting in the formation of a larger molecule and the release of a water molecule
• hydrolysis reaction


  opposite to a condensation reaction, large molecules covalent bond breaks to make smaller molecules, by the addition of a water molecule
• carbohydrates


  provide energy, main source of fuel for physical activity
• proteins 


  required for structure and function and regulation of body's tissues
• lipids


  provide energy for producing hormones, help digestion and absorption of food
• vitamins/minerals


  essential for well-being of body and help with the immune system
• nucleic acid 


  make up the genetic information DNA/RNA
• water 


  used in all cells, organs and tissues to regulate temperature and maintain other bodily functions
• primary structure 


  is the sequence of amino acids which is determined by the order of DNA. There are many different combinations so there are many different primary structures resulting in different shapes
• secondary structure


  is the coiling/folding of parts of the protein molecule due to the formation of H bonds
• tertiary structure


  the overall 3D shape which is the result of interactions between parts of the protein molecule as hydrophobic side chains are contained in the centre of the molecule
• quaternary structure


  protein structure which consists of more than one polypeptide chain (e.g. haemoglobin and insulin)
• prosthetic group


  is a non-protein molecule that forms as essential part of a certain enzyme
• deficiency 


  a lack or shortage of a required element/compound
• Rf (retardation factor)


  used to analyse results, you compare Rf values to known values
• chitin (carbohydrate)


  exoskeleton of insects
• peptidoglycan (carbohydrate)


  basis of cell walls
• sterol


  type of lipid found in a cell with dual hydrophobic/phillic nature
• cholesterol


  make bile salts, found in cell membranes where they regulate fluidity
• amphoteric


  (amino acids) has both acidic and alkaline properties
• DNA (deoxyribonucleic acid)


  found in nucleus for eukaryotic cells, double strand ATCG
• RNA (ribonucleic acid)


  needed to translate the code from DNA to make new proteins, single strand AUCG
• base pair 


  the pair of complementary bases in a double-stranded nucleic acid molecule, a purine in on strand linked by a H bond to a pyrimidine on the other strand