Archives: Questions and Answers

Explain that in non-cyclic photophosphorylation: • photosystem I (PSI) and photosystem II (PSII) are both involved • photoactivation of chlorophyll occurs • the oxygen-evolving complex catalyses the photolysis of water • ATP and reduced NADP are synthesised

Explain that in cyclic photophosphorylation: • only photosystem I (PSI) is involved • photoactivation of chlorophyll occurs • ATP is synthesised

State that cyclic photophosphorylation and non-cyclic photophosphorylation occur during the light-dependent stage of photosynthesis

Describe and use chromatography to separate and identify chloroplast pigments (reference should be made to Rf values in identification of chloroplast pigments)

Interpret absorption spectra of chloroplast pigments and action spectra for photosynthesis

Describe the role of chloroplast pigments (chlorophyll a, chlorophyll b, carotene and xanthophyll) in light absorption in thylakoids

State that within a chloroplast, the thylakoids (thylakoid membranes and thylakoid spaces), which occur in stacks called grana, are the site of the light-dependent stage and the stroma is the site of the light-independent stage

Explain that energy transferred as ATP and reduced NADP from the light-dependent stage is used during the lightindependent stage (Calvin cycle) of photosynthesis to produce complex organic molecules

Describe and carry out investigations using simple respirometers to determine the effect of temperature on the rate of respiration

Describe and carry out investigations using redox indicators, including DCPIP and methylene blue, to determine the effects of temperature and substrate concentration on the rate of respiration of yeast