Photosynthesis exam 2023 with verified questions and answers

Important role of membranes in plant cells? -phospholipid bilayers within chloroplasts are impermable to protons -Thylakoid membranes contain electron transport chain proteins What is the process of photosynthesis? Light dependent reaction (uses oxygen and water) to produce NADP reduced to assist the light independent reaction produces CO2 and hexose. What enzyme fixes carbon dioxide in P/S? RuBisCO What is the grana? thylakoid stacks How are the structure of thylakoids adapted for function? - large surface area for a light dependent reaction - Contain pigment - Contain electron carrier proteins for ATP synthesis Role of accessory pigments pass energy to reaction centre Role of photosynthetic pigments Absorb light energy to excite electrons Why do primary pigments loose electrons? To become oxidised Why do plants in water absorb different wavelengths of light? Water absorbs light Why wouldn't rate of photosynthesis increase at higher light intensities? Another factor becomes limiting Possible usage of triode phosphate (TP)? - Production of amino acids - Production of glucose From which molecule is TP synthesised during the light-dependent stage? GP Why would a plant be higher in water on a sunny day? oxygen trapped within the weed increases buoyancy What is a limiting factor? The factor that will determine the rate when at a sub-optimal level What is the primary photosynthetic pigment? chlorophyll a Advantage of a plant have a range of accessory pigments? Can absorb a range of different wavelengths of light energy What compound is synthesised in the light-dependent stage as a result of an electrical and PH gradient across the thylakoid membrane? ATP Where does the Calvin cycle take place? stroma What enzyme catalyses the fixation of C02? rubisco What is the first stable product of carbon fixation? GP What compound is regenerated in the calving cycle RUBP What 2 polysaccharides can be synthesised from the end products of the light independent stage? Amylose and Cellulose What organisms use photosynthesis? autotrophs What channels are grana joined by? Lamellae Process of light dependent reaction: Energy from sunlight is used to from ATP Hydrogen ions from water is used to reduce conenyme NADP to NADPH Process of light independent stage: Hydrogen ions from NADPH and CO2 is used to form organic molecules supplies energy What wavelengths do photosystem 1 and 2 absorb? 1- 700nm 2- 680nm What happens to electrons lost at PS11 Replaced from H20 breakdown from the sun Summary of light-independent reactions (the Calvin cycle) Fixation- Co2 is fixed Reduction- GP reduced to TP by addition of hydrogen ions for LIS. Regeration- RUBP is regranted fro TP recycled