Chloroplast structure and function

Cards (25)

  • What organelles in plant cells are responsible for photosynthesis?
    Chloroplasts
  • What is the diameter range of chloroplasts?
    2–10 μm
  • What surrounds each chloroplast?
    A double-membrane envelope
  • What type of bilayer makes up the chloroplast envelope membranes?
    Phospholipid bilayer
  • What is the permeability of the outer membrane of chloroplasts?
    Permeable to ions and small molecules
  • What does the inner membrane of chloroplasts contain?
    Transport proteins for selective entry
  • What is the fluid inside chloroplasts called?
    Stroma
  • What molecules are dissolved in the stroma?
    CO₂, sugars, enzymes, and other molecules
  • What are the flattened sacs in the stroma called?
    Thylakoids
  • What do thylakoid membranes contain?
    Pigments, enzymes, and electron carriers
  • What structures do thylakoids stack to form?
    Grana
  • What connects the grana in chloroplasts?
    Stroma lamellae
  • Why do the membranes of the grana create a large surface area?
    To maximize light absorption
  • What are pigment molecules arranged in within chloroplasts?
    Light-harvesting clusters known as photosystems
  • How are pigment molecules arranged in a photosystem?
    In funnel-like structures
  • What type of ribosomes are found in the stroma?
    70S ribosomes
  • What does the loop of DNA in chloroplasts code for?
    Some chloroplast proteins
  • Where are other chloroplast proteins coded for?
    By the DNA in the plant cell nucleus
  • What are sugars formed during photosynthesis stored as?
    Starch inside starch grains
  • What are the two stages of photosynthesis and where do they occur?
    • Light-dependent stage: occurs on thylakoid membranes
    • Light-independent stage: occurs in the stroma
  • What adaptations do chloroplasts have for photosynthesis?
    • Stroma: Contains enzymes for light-independent reactions
    • Grana: Large surface area for photosystems
    • DNA: Codes for proteins and enzymes
    • Ribosomes: Translate proteins coded by cpDNA
    • Inner membrane: Selective transport proteins control flow
  • What is the role of the stroma in chloroplasts?
    Contains enzymes for light-independent reactions
  • How do grana contribute to photosynthesis?
    Provide a large surface area for light absorption
  • What is the function of ribosomes in chloroplasts?
    Translate proteins coded by cpDNA
  • What do selective transport proteins in the inner membrane control?
    Flow of molecules between stroma and cytosol