DNA and common elements :: Biology

Biology Topic Three Chemical elements element Function Prokaryotes Plants animals Sulphur proteins proteins Proteins Calcium Flagella movement Forms cell plate during cytokinesis Shells, bones, vesicle fusion Phosphorus Nucleic acids and ATP Nucleic acids and ATP Nucleic acids and ATP iron Cytochrome- used in respiration Cytochromes-used in reparation Cytochromes – used in mitochondria respiration, haemoglobin Sodium Main cation in cytoplasm Transmission of nerve impulses Water - Polar molecule - Oxygen has slight negative charge - Hydrogen has slight positive charge - Opposite charges attract - This forms hydrogen bonds - This is called cohesion - Water can store lots of heat - Water can dissolve other polar molecules - Other substances can form ions in water and dissolve Organisms and properties of water - Can be used as a coolant because it requires a lot of energy to break the hydrogen bonds to go from liquid to gaseous state - Is a good medium for metabolic reactions due to the fact it is a good solvent due to its polarity. Watery cytoplasm dissolve substances and metabolic reactions can take place easily. - Water can be a good transport substance due to its high specific heat. Cohesion is the forming of hydrogen bonds and hydrolysis is the breaking of hydrogen bonds. Organic and inorganic compounds - Organic compounds are those that contain carbon and are found in living organisms. - They do not include carbonates, hydrogencarbonates and oxides of carbon. Identifying: Ribose and Glucose - Ring structure - One carbon outside the ring - CnH2nOn with n = 5 for ribose and n = six for glucose - Each carbon has four bonds - Eachs carbon has an Oh bond and an H bond. Identifying: Amino acids - Nitrogen is the key atom - Twenty amino acids used as proteins - They all have the same structure of The R is changeable and can be any of many different things. Identifying: Fatty Acids - At one end is CH3 group and at the other COOH or carboxylic acid group - Between these is a number of CH or CH2 groups. - Double bonds mean that the fatty acid is unsaturated - If there are lots of double bonds then the fatty acid is called polyunsaturated. Identifying: Carbohydrates Monosaccharides: Glucose, Galactose, Fructose Disaccharides: Matose (glucose + glucose), Lactose (glucose + galactose), Sucrose (glucose + fructose) Polysaccharides: Starch, Glycogen, Cellulose. All from poly-glucose In plants carbohydrates serve as an energy source and component of sucrose while it is also used to build cell walls and transport things In animals it is broken down to produce energy, and is a sugar in milk and used as an energy store.