Outline the need for energy in living organisms[6] #
- Anabolic reactions e.g growth.
- Active transport of sustains against concentration gradient.
- Phagocytosis, pinocytosis , exocytosis, endocytosis.
- Electrical transmission of nerve impulse.
- Mechanical, contraction of muscles.
- Maintainace of temperature heat from respiration.
- Bioluminescence.
- Electrical discharge.
Explain the different energy values of carbohydrate, lipid and protein as respiratory substrates. [6] #
- idea of lipid > protein > carbohydrate ;
- A lipid has more energy than either protein or carbohydrate
- comparative figures ; e.g. 39.4, 17.0 and 15.8
- kJ g-1 / per unit mass;
- more hydrogen atoms in molecule, more energy;
- lipid have more, hydrogen atoms / C-H bonds;
- (most) energy comes from oxidation of hydrogen to water;
- using reduced, NAD / FAD;
- in ETC;
- detail of ETC;
- ATP production
Describe the structure and synthesis of ATP and its universal role as the energy currency in all living organisms. #
[8][ZIMSEC June 2017/2/11(b)] #
- nucleotide ;
- adenine + ribose / pentose + three phosphates ;
- loss of phosphate leads to energy release / hydrolysis releases 30.5 kJ ;
- ADP + Pi ↔ ATP (reversible reaction);
- synthesised during, glycolysis / Krebs cycle / substrate level phosphorylation ;
- synthesised, using electron carriers / oxidative phosphorylation /photophosphorylation
- in, mitochondria / chloroplasts;
- ATP synthase / ATP synthetase;
- chemiosmosis / description;
- used by cells as immediate energy donor;
- link between energy yielding and energy requiring reactions;
- active transport / muscle contraction / Calvin cycle / protein synthesis
Explain the role of ATP in active transport of ions and in named anabolic reactions.[6] #
- maintenance of, constant / stable, internal environment ;
- irrespective of changes in external environment ;
- negative feedback ;
- receptor /appropriate named cell, detects change in, parameter / blood glucose concentration ;
- (receptors are) beta / alpha , cells ;
- in, Islets of Langerhans / pancreas ;
- insulin / glucagon, released ;
- action taken by effector / correct action described (liver / muscle, cell) ;
