Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
1. (a) name of molecule; function of molecule; Fe examples: (b) hemoglobin; transports oxygen (in the blood); myoglobin; store of oxygen in muscle; cytochromes / ferredoxin; electron carrier; (do not accept avoids anemia) name of molecule; function of molecule; P examples: 2 max 2 max ATP / ADP; energy storage and release; DNA / RNA / nucleotides; genetic (hereditary) material; phospholipids structural component of membrane [4] 2. (a) compounds containing carbon (found in living organisms) 1 (b) carbon, hydrogen and oxygen 1 (c) (i) (ii) proteins / named protein / DNA / RNA / chlorophyll / amino acid / other compound containing nitrogen 1 DNA / RNA / nucleotides / ATP / phospholipids / GP (glycerate 3 phosphate) / other compound containing phosphorus 1 [4] 1 3. Award [1] for each element and its role. eg C / carbon in forming organic molecules / carbohydrates / fats / proteins / nucleic acids; eg H / hydrogen in forming organic molecules / carbohydrates / fats / proteins / nucleic acids / reducing / fixing CO2 in photosynthesis; eg O / oxygen in aerobic respiration; eg N / nitrogen in formation of amino acids / proteins / nucleotides / ATP / nucleic acids / DNA / RNA; eg P / phosphorus in formation of nucleotides / ATP / nucleic acids / DNA / RNA; eg Ca / Ca2+ / calcium in muscle contraction / nerve transmission / formation of bones / teeth; eg. Fe / Fe2+ / iron in formation of hemoglobin / catalase; eg Na / Na+ / sodium in nerve transmission / osmoregulation; eg K / K+ / potassium in stomatal opening etc; [4] 4. D [1] 5. C [1] 6. D [1] 7. Responses must include reference to coolant, transport and habitat to receive full marks. coolant: lots of energy required to heat water / water has a high specific heat capacity / hydrogen bonding of water molecules; when water evaporates energy is used; cools organism; eg sweating / panting / transpiration; transport: water is polar / universal solvent; dissolves many organic / inorganic substances; movement of water carries substances around organism; eg blood / phloem / xylem / adhesion / cohesion; medium for external transport (eg gametes); habitat: water is transparent; allows light through for photosynthetic organisms; 2 organisms live in / on water / surface tension for surface creatures / buoyancy; contains dissolved gases; fish / aquatic organisms survive under ice at surface; (Plus up to [2] for quality) 8 max [8] 8. Answers must discuss both carbohydrates and lipids to receive full marks. carbohydrates: stored as glycogen (in liver); short-term energy storage; more easily digested than lipids so energy can be released more quickly; more soluble in water for easier transport; 3 max lipids: stored as fat in animals; long-term energy storage; more energy per gram than carbohydrates; lipids are insoluble in water less osmotic effect; (Plus up to [2] for quality) 3 max 5 max [5] 9. condensation; involves the removal of water to join monosaccharides together / equation to show this; catalysed by enzymes; consists of many monosaccharides linked (glycosidic) to make polysaccharide; [2] 10. B [1] 11. C [1] 12. C [1] 3 13. (a) peptide bonds / peptidic bonds; 1 (b) alpha-helix / alpha helices; 1 (c) ionic / polar / hydrogen / hydrophobic / van der Waals’ / disulfide; (not covalent) 1 linking together of polypeptides to form a single protein; using the same bonding as for tertiary structure; linking of a non-polypeptide structure / prosthetic group; named example of quaternary structure eg hemoglobin (has four polypeptides); 2 max (d) [5] 14. C [1] 4