Algae are a diverse group of photosynthetic eukaryotes in the kingdom Protoctista. Rhodomonas salina and Skeletonema costatum are two species of alga that live in seawater. Fig. 1.1 shows a scanning electron micrograph of $$\(R\)$$. salina, which is a unicellular organism. $$\(R\)$$. salina is red in colour. Fig. 1.1 Fig. 1.2 shows a scanning electron micrograph of $$\(S\)$$. costatum, which is also a unicellular organism. The individual cells can group together in a chain. S. costatum is yellow-brown in colour. Fig. 1.2 （b）The extract of the photosynthetic pigments from each of the two species was used to obtain absorption spectra as shown in Fig．1．4． Fig． 1.4 The student planned to investigate the effect of light wavelength on the rate of photosynthesis in $$\(R\)$$ ．salina and S．costatum． The student planned to determine the rate of photosynthesis in the two species when they were exposed to three different colours of light： －blue light，peak wavelength of 455 nm －green light，peak wavelength of 550 nm －red light，peak wavelength of 670 nm ． Use Fig. 1.4 to compare the expected rates of photosynthesis for the two species in blue, green and red light. blue light ................................................................................................................................ ............................................................................................................................................... . ............................................................................................................................................... . green light ............................................................................................................................. ............................................................................................................................................... . ............................................................................................................................................... . red light ................................................................................................................................. .. ............................................................................................................................................... . ............................................................................................................................................... .
Exam No：9700_w24_qp_51 Year：2024 Question No：1(b)
Answer:
Knowledge points:
13.1.1 describe the relationship between the structure of chloroplasts, as shown in diagrams and electron micrographs, and their function
13.1.10.1 energetic electrons release energy as they pass through the electron transport chain (details of carriers are not expected)
13.1.10.2 the released energy is used to transfer protons across the thylakoid membrane
13.1.10.3 protons return to the stroma from the thylakoid space by facilitated diffusion through ATP synthase, providing energy for ATP synthesis (details of ATP synthase are not expected)
13.1.11.1 rubisco catalyses the fixation of carbon dioxide by combination with a molecule of
13.1.11.2 ribulose bisphosphate (RuBP), a 5C compound, to yield two molecules of glycerate 3-phosphate (GP), a 3C compound
13.1.11.3 GP is reduced to triose phosphate (TP) in reactions involving reduced NADP and ATP
13.1.11.4 RuBP is regenerated from TP in reactions that use ATP
13.1.12 state that Calvin cycle intermediates are used to produce other molecules, limited to GP to produce some amino acids and TP to produce carbohydrates, lipids and amino acids
13.1.2 explain that energy transferred as ATP and reduced NADP from the light-dependent stage is used during the light-independent stage (Calvin cycle) of photosynthesis to produce complex organic molecules
13.1.3 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
13.1.4 describe the role of chloroplast pigments (chlorophyll a, chlorophyll b, carotene and xanthophyll) in light absorption in thylakoids
13.1.5 interpret absorption spectra of chloroplast pigments and action spectra for photosynthesis
13.1.6 describe and use chromatography to separate and identify chloroplast pigments (reference should be made to Rf values in identification of chloroplast pigments)
13.1.7 state that cyclic photophosphorylation and non-cyclic photophosphorylation occur during the light-dependent stage of photosynthesis
13.1.8.1 only photosystem I (PSI) is involved
13.1.8.2 photoactivation of chlorophyll occurs
13.1.8.3 ATP is synthesised
13.1.9.1 photosystem I (PSI) and photosystem II (PSII) are both involved
13.1.9.2 photoactivation of chlorophyll occurs
13.1.9.3 the oxygen-evolving complex catalyses the photolysis of water
13.1.9.4 ATP and reduced NADP are synthesised
Solution:
Download APP for more features
1. Tons of answers.
2. Smarter Al tools enhance your learning journey.
IOS
Download
Download
Android
Download
Download
Google Play
Download
Download