Remember! In order to carry out cellular processes, cells need ENERGY. The energy in cells is stored in the form of glucose, a sugar. Autotrophs create their own sugars; heterotrophs have to consume sugars.

This process is called photosynthesis. Autotrophs Autotrophs are producers – they make their own energy. Plants capture the energy from sunlight & use it to make sugars for energy. This process is called photosynthesis.

Photosynthesis

Photosynthesis The process in which plants use solar energy to convert water & carbon dioxide into carbohydrates (sugars) & oxygen (a waste product)

Photosynthesis Photosynthesis occurs in the chloroplasts of plant cells. Most chloroplasts are found in the leaves. There could be up to 100 chloroplasts per cell in the leaf!

The Balanced Photosynthesis Equation Reactants  Products 6CO2 + 6H2O + Sunlight  C6H12O6 + 6O2 Carbon Dioxide + Water + Sunlight  Sugars + Oxygen

Photosynthesis Plants get their CO2 from the water or air where they live. Plants take up water from the soil with their roots. When plants soak up the sunlight, they can use the solar energy to turn the water & CO2 into sugar for energy!

Light & Pigments The photosynthesis reaction requires solar energy. That sunlight is captured by chlorophyll in the chloroplasts.

Chlorophyll Pigment molecule that absorbs light energy Found in the chloroplasts Chlorophyll can absorb almost all wavelengths of light, but reflects green light.

The Process of Photosynthesis Photosynthesis occurs in the chloroplasts. Parts of the chloroplast include: Stroma Grana (stack of thylakoids)

The Process of Photosynthesis Photosynthesis takes place in 2 reactions: Light Dependent: needs sunlight, occurs in the thylakoids Light Independent (The Calvin Cycle): does not require sunlight, takes place in the stroma

The Process of Photosynthesis The Light Dependent Reaction The chlorophyll inside the chloroplasts absorbs all light wavelengths from the sun & reflects green light.

2. Energy in the light waves excites electrons in the water molecules, which causes the electrons to gain energy.

The Light Dependent Reactions take place in the thylakoids of the chloroplast!

Light Dependent Reactions 3. The extra energy converts ADP into ATP and NADP+ into NADPH. Oxygen is released as a byproduct.

NADPH Electron carrier The energy from the excited electrons from the water molecules are carried to the Calvin Cycle to help create sugars

The Calvin Cycle The Light Independent Reactions 4. ATP, NADPH, and CO2 are used during the light independent reaction. 5. Energy is used to bond hydrogen atoms and CO2 molecules to produce glucose (C6H12O6).

The Calvin Cycle takes place in the stroma of the chloroplast!

Chloroplast

Factors that Affect Photosynthesis Shortage of water Temperature Intensity of light