Photosynthesis

• What shape are chloroplasts?

  Oval-shaped
• Where do chloroplasts mainly occur in plants?

  In the leaves
• What surrounds a chloroplast?

  A double membrane
• What fills the chloroplast?

  A fluid matrix known as the stroma
• What are the disc-shaped membranes in the stroma called?

  Lamellae or thylakoids
• What do lamellae form?

  Small stacks known as grana
• What pigment is embedded in the lamellae?

  Chlorophyll
• How are two grana connected?

  By a membrane known as the intergranum
• What does the stroma contain?

  Enzymes, starch grains, oil droplets, and ribosomes
• What process occurs in the chloroplasts?

  The process of photosynthesis
• What is built up during photosynthesis?

  Energy-rich carbohydrates (glucose)
• What does chlorophyll absorb?

  Radiant energy from the sun
• What are the raw materials required for photosynthesis?

  Water (H₂O) and carbon dioxide (CO₂)
• What is released as a by-product of photosynthesis?

  Oxygen (O₂)
• What is photosynthesis?

  • Process whereby plants produce their own food
  • Plants are autotrophs
  • Use sun's energy to make carbohydrates from CO₂ and H₂O
  • Chlorophyll is used to trap light
• What does the term "autotroph" mean?

  Organisms that produce their own food
• What is the role of chlorophyll in photosynthesis?

  It absorbs light at specific frequencies
• Where does photosynthesis happen in a plant?

  Anywhere that is green, such as leaves and stems
• What adaptations do leaves have for photosynthesis?

  • Flattened for large surface area
  • Thin for sunlight penetration
  • Borne on a petiole for maximum exposure
  • Transparent epidermal cells for deeper sunlight penetration
  • Network of vascular bundles for water and carbohydrate transport
  • Stomata for gaseous exchange
  • Palisade mesophyll for maximum sunlight absorption
  • Elongated palisade cells for deeper sunlight penetration
  • Densely packed palisade cells for faster diffusion
  • Loosely packed spongy mesophyll for gas diffusion
• What is the word equation for photosynthesis?

  Carbon dioxide + water + sunlight → glucose + oxygen
• What is the chemical equation for photosynthesis?

  $CO_2 +$$H_2O +$$\text{Radiant Energy} \rightarrow C_{6}H_{12}O_{6} +$$O_{2}$
• What are the two phases of photosynthesis?

  1. Light phase (Photolysis)
  2. Dark phase (Calvin Cycle)
• Where does the light phase of photosynthesis occur?

  In the grana of the chloroplast
• What happens during the light phase of photosynthesis?

  Water is split into oxygen and hydrogen molecules
• What are the products of the light phase of photosynthesis?

  Hydrogen atoms, ATP, and oxygen
• What binds to hydrogen atoms during the light phase?

  NADP to form NADPH
• Where does the Calvin cycle occur?

  In the stroma of the chloroplast
• What is needed for the Calvin cycle to function?

  Hydrogen and ATP energy from the light-dependent phase
• What is produced in the Calvin cycle?

  Glucose
• What happens to glucose after photosynthesis?

  It is converted into starch for storage
• How do plants form proteins?

  By absorbing nitrogen from soil as nitrates
• What happens to excess glucose in plants?

  It is converted into fats and oils
• What is the importance of photosynthesis?

  • Maintains carbon-oxygen balance in the atmosphere
  • Provides radiant energy for heterotrophs
  • Fossil fuels originate from photosynthesizing plants
• What factors affect photosynthesis?

  • Light
  • Temperature
  • Chlorophyll
  • Carbon dioxide