Photosynthesis

• Photosynthesis captures light by using chlorophyll molecules, which is converted to chemical energy in the form of ATP and NADH.
• Photosynthesis has 2 major stages:

  1. Energy transduction
  2. Carbon Assimilation (Calvins Cycle)
• Energy transduction occurs in the chloroplast and thylakoid and includes:

  • light harvesting
  • electron transport to NADPH for simutaneous proton pumping
  • ATP synthesis
• Carbon Assimilation reaction include:

  • Calvins cycle
  • starch biosynthesis in chloroplast (stroma)
  • sucrose synthesis in the cytosol
• The chloroplast are 1-5nm long, 1-10nm wide.
• The chloroplasts have 3 membranes:

  1. Inner membrane
  2. Outer membrane
  3. Thylakoid
• The Inner membrane encloses the stroma with a gel like matrix called the cristae and forms a permeability barrier. the transport proteins control the flow of most metabolite between the inter membrane space.
• The outer membrane transports membrane proteins called porins, which are a passageway for solutes. They are free and permeable fro small proteins and ions.
• The chloroplast has 3 compartments:

  1. Stroma
  2. Inter membrane
  3. Thylakoid
• stroma is for carbon fixation
• Intermembrane space is the space between the two membranes of a cell.
• Thylakoid is for light reactions
• Light dependent reaction is the first stage of photosynthesis. the captured light is absorbed by chlorophyll. it is energy that is converted into stored chemical energy into energy carriers. These energy carriers release their full energy for light dependent reactions, then are released to obtain more energy.
• Non-light dependent reactions is the Calvin Cycle


  It is the second stage of photosynthesis where they use product of light dependent reactions to form carbohydrates (CO2) molecules using ATP and NADPH, then we build glucose.
• The outcome of the calvins cycle is 3 carbons, 3 sugars (glucose). the plants break down to perform cellular respiration.
• Fill in blanks

  A) Chloroplast

  B) Thylakoid

  C) Light reactions

  D) Light

  E) H2O

  F) ATP

  G) Calvins Cycle

  H) Stroma

  I) Sugar

  
• Both plants and animal cells breakdown glucose to generate ATP
• Animals must have an external source of glucose
• ATP is generated in both respiration and photosynthesis, which is responsible by ATP synthase.
• In Photosynthesis, plants use their leafs to trap light energy. they use the energy of the sun to change water and carbon dioxide into sugar = glucose.
• Animal cells obtained by food they eat and using it to maintain homeostasis and perform other metabolic functions. This can be done by cellular respiration.
• Origin of chloroplasts and mitochondria (endosymbiosis)


  The mitochondria and chloroplasts contain DNA, ribosomes and some are able to make proteins. They both have an inner and outer membrane and both are originated by bacterial symbionts.

  They are engulfed by prokaryotes that lived once from independent organisms.