Photosynthesis

• What does the absorption spectrum show?

  The range of different wavelengths of light that a photosynthetic pigment absorbs, and in what amounts
• What does the action spectrum show?

  The rate of photosynthesis in a place against the wavelength of light absorbed
• What makes up chlorophyll?

  Different photosynthetic pigments
• Name the 4 main photosynthetic pigments in chlorophyll?

  Chlorophyll a, chlorophyll b, carotenoids & phaeophytin
• What are the two carotenoids?

  Carotene & xanthophyll
• What colour is chlorophyll a?

  Blue-green
• What colour is chlorophyll b?

  Yellow-green
• What colour is carotene?

  Orange
• What colour is xanthophyll?

  Yellow
• What colour is phaeophytin?

  Grey
• What is phaeophytin?

  A breakdown product of all the other pigments
• What is the primary light absorbing pigment in plants?


  Chlorophyll a
• What colour light does chlorophyll a predominantly reflect?

  Green
• What colours light does chlorophyll a predominantly absorb?

  Red & blue
• What are the accesory pigments?

  Chlorophyll b and the carotenoids
• What is the purpose of a plant having accesory pigments?

  Extend the range of wavelengths of light that a plant can absorb
• What is the fluid filling a chloroplast known as?

  Stroma
• Is the chloroplast membrane double or single?

  Double
• What does the chloroplast envelope refer to?

  The double membrane
• What is the name of a single flattened membrane disc in a chloroplast containing chlorophyll?

  Thylakoid
• What is a stack of flattened membrane discs found in a chloroplast known as?

  Granum
• Plural of granum?

  Grana
• What are lamellae in chloroplasts?

  Extensions of thylakoid membranes which connect grana and provide structural support (e.g keeps grana at set distances away from each other)
• What are the two inputs of photosynthesis?

  Carbon dioxide and water
• What are the two outputs of photosynthesis?

  Glucose and oxygen
• Explain what photosynthesis is?

  The process by which living organisms capture energy from the sun using chlorophyll and use it to convert carbon dioxide and water into simple sugars
• What are the two stages of photosynthesis?

  Light-dependent reaction & light-independent reaction
• What is the other name for the light-dependent stage of photosynthesis?

  Photophosphorylation
• Where does photophosphorylation take place?

  Across the thylakoid membrane
• Where do the electrons which get moved along the ETC in photophosphorylation come from?

  The photolysis of water which produces hydrogen ions, electrons and oxygen
• What is the name for the reaction during photophosphorylation where water is split?

  Photolysis
• What is used to exite electrons at the beginning of the ETC?

  Light energy
• What is the name of the first light absorbing protein in the ETC?

  PSII
• During photophosphorylation, the energy released due to electrons moving along the ETC is used for what?

  To pump hydrogen ions (protons) across the thylakoid membrane
• What is the name of the second protein where light can be absorbed during photophosphorylation?

  PSI
• What is the terminal electron acceptor in photophosphorylation?

  NADP
• What happens to the electron when it reaches the end of the ETC in photophosphorylation?


  It is accepted by NADP, which alongside a hydrogen ion forms NADPH
• What is the name of the enzyme involved with chemiosmosis?

  ATP synthase
• Explain what happens during chemiosmosis in photophosphorylation?

  Hydrogen ions (protons) diffuse through the enzyme ATP synthase which releases energy used to synthesise ATP from ADP and an inorganic phosphate
• What are the photophosphorylation inputs?

  Light and water