Photosynthesis - quizlet

• Chloroplast


  The organelle in which photosynthesis occurs
• Calvin cycle


  The reactions of the light independent stage of photosynthesis

  
• Compartmentalisation


  The use of intracellular membranes to separate metabolic processes within the cell e.g. nuclear envelope around the nucleus.
• Grana


  A stack of thylakoid membranes in chloroplasts.

  
• Light dependent stage


  The first stage of photosynthesis, which uses light energy to produce ATP and reduced NADP.

  
• Light independent stage


  The second stage of photosynthesis, which used CO2, ATP and reduced NADP to produce organic molecules.

  
• Limiting factor


  A variable that limits the rate of a particular process.
• NAD


  A coenzyme molecule found in all living cells which can be reduced by removing hydrogen atoms and accepting electrons from substrates.
• NADP


  A coenzyme that is reduced (gains H atoms) in the light dependent stage of photosynthesis and is oxidised (loses H atoms) in the light independent stage.
• Photolysis


  An enzyme-catalysed reaction of photosynthesis that uses light energy to split water

  
• Photosynthesis


  The set of reactions in chloroplasts that use light energy, water and CO2 to produce organic molecules.

  
• Stroma


  The fluid-filled matrix of chloroplasts and site of light independent stage of photosynthesis.
• Thylakoid


  The inner membrane of a chloroplast and site of the light dependent stage of photosynthesis

  
• Stomata


  Pores/ holes on the leaf where O2 exits and CO2 enters
• Calvin Cycle


  Final stage of photosynthesis. Takes place in the stroma of chloroplasts. Produced ATP and reduced NADP.
• Carbon Fixation


  The conversion of gaseous CO2 into organic molecules.
• Rubisco


  The enzyme that catalyzes the first step of the Calvin cycle (the addition of CO2 to RuBP).
• RuBP


  five-carbon carbohydrate that combines with CO2 in the first step of the Calvin Cycle
• Limiting Factor


  A factor that limits the rate of a process. If the limiting factor is increased the process will take place at a faster rate. This increase in rate does not go on indefinitely. Eventually the rate levels off as other factors become limiting. Light intensity and carbon dioxide concentration are limiting factors for photosynthesis.
• Compensation Point


  There is a particular level of light intensity at which rate of photosynthesis equals rate of respiration.
• ATP


  The main energy source for all cells; a molecule that is catabolized to release energy to drive metabolic processes
• Where does the light dependent stage occur?


  In the grana
• Where does the light independent stage occur?

  In the stroma
• How is the inner membrane adapted for its role?

  It is embedded with transport proteins and is less permeable than the outer membrane. This enables control over which substances can enter the stroma from the cell cytoplasm.
• How are the thylakoid membranes adapted for their role?


  They are stacked which produces a large surface area for the light dependent reaction to occur.
• How are the photosynthetic pigments adapted for their role?


  They are organised in photosystems which maximise the efficiency of light energy absorption.
• How is the grana adapted for its role?


  It is surrounded by the stroma meaning products from the light dependent reaction are able to pass directly to the enzymes catalysing the light independent reactions.
• How are chloroplasts adapted for their role?


  They contain their own DNA and ribosomes which enables them to produce some of their photosynthetic proteins rather than importing them from the cell cytoplasm.
• Light energy is absorbed by chlorophyll molecules, which are located within pigment protein complexes called photosystems.
• The electrons excited by light move through an electron transport chain (ETC) that uses this energy to pump protons across the thylakoid membrane into the lumen of the thylakoids
• NADPH is produced when electrons are passed down another ETC, reducing NADP+ to NADPH