Practise IB Biology HL C1.2 with pathway diagrams and data questions covering glycolysis, link reaction, Krebs cycle, chemiosmosis, anaerobic respiration and ATP yield.
All cells require a supply of energy and can transform the energy that they obtain in different ways.
Explain the properties of ATP that make it useful for distributing energy within cells.
a. used as a source/(temporary) store of energy / is the energy currency of the cell;
b. releases energy when converted to ADP/when a phosphate is removed;
c. amount of energy released can be used/sufficient for (many metabolic) tasks;
d. active transport/another valid example;
e. ATP to ADP conversion is reversible / ATP can be regenerated from ADP;
f. can be produced in different ways/using energy from different sources/by aerobic or anaerobic respiration;
g. stable within cell so does not release energy prematurely/before needed;
h. small molecule/soluble so can move easily/quickly (through the cell);
i. cannot diffuse through membranes so is not lost from cell/to the environment;
h. The idea of ATP being small/soluble
must be there along with its
moveability.
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Monosaccharides can be used to make polysaccharides, and can also be combined with other types of carbon compound to form molecules such as nucleotides.
Outline, with examples, the wide range of uses of adenosine triphosphate (ATP) in cells.
a. movement of cells/chromosomes and example of movement;
b. movement of flagellum/cilium;
c. endocytosis/exocytosis;
d. detachment of myosin heads from actin filaments / myosin heads change their angle/become cocked;
e. active transport and example of use of active transport;
f. anabolic reactions / polymerization example / example of synthesizing macromolecules;
g. generation of heat and to provide optimum temperature for enzyme activity / in homeostasis / to maintain body temperature;
h. phosphorylation of substrates in glycolysis;
i. phosphorylation of substrates in photosynthesis light-
independent reaction/Calvin cycle;
For a. accept descriptions of cells (e.g. amoeboid phagocyte
moving to site of infection) or chromosomes (e.g. anaphase,
chromosomes moving to opposite poles).
For d. ignore 'muscle contraction'.
For e. E.g. sodium-potassium pump (in neurons) / maintaining resting potential in neurons / generation of root pressure / villus epithelial cells / selective reabsorption in kidney.
For e. do not accept transport of large molecules as example.
For f. accept examples such as DNA replication / transcription / translation / and other examples of formation of
macromolecules.
For h. accept phosphorylation of glucose (to glucose-6-phosphate) or phosphorylation of fructose-6-phosphate (to
fructose 1,6-biphosphate).
For i. accept formation of triose phosphate and formation of ribulose bisphosphate (regeneration of RuBP).
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Which reaction does not cause a net release of energy?
ADP combines with inorganic phosphate to form ATP
ATP releases inorganic phosphate to form ADP
Loss of hydrogen from reduced NAD
Oxidation of reduced FAD
A