Photosynthesis Michael Slemp

BELL WORK Explain the difference between light dependent reactions to light independent reactions. Explain the difference between light dependent reactions to light independent reactions. Use complete sentences and be descriptive. Use complete sentences and be descriptive.

Review All cells need energy in form of ATP All cells need energy in form of ATP Most animal cells need to eat energy-rich molecules like sugars to get their energy Most animal cells need to eat energy-rich molecules like sugars to get their energy Some organisms, like plants, are able to produce their own energy via photosynthesis or chemosynthesis. They are called producers. Some organisms, like plants, are able to produce their own energy via photosynthesis or chemosynthesis. They are called producers.

Sunlight energy Photosynthesis Energy rich molecule (glucose) Plants, animals and humans use glucose as source of energy

Types of Energy Light Energy Light Energy Energy from the sun Energy from the sun Human use: solar calculators, solar heaters Human use: solar calculators, solar heaters Plants are able to convert light energy into chemical energy during the process of photosynthesis Chemical Energy Chemical Energy Energy hidden in the bonds of chemical molecules (like sugar/glucose. ATP) Energy hidden in the bonds of chemical molecules (like sugar/glucose. ATP) This energy is released when bonds are broken This energy is released when bonds are broken

Pair Share 1. Describe the difference between light and chemical energy. 2. Can humans convert light energy into chemical energy? 3. What organisms can convert light energy into chemical energy? 4. What is this process called?

Pair Share 1. Describe the difference between light and chemical energy. Light energy is the energy from sunlight and chemical energy is hidden in bonds of chemical molecules. 2. Can humans convert light energy into chemical energy? No 3. What organisms can convert light energy into chemical energy? Plants 4. What is this process called? Photosynthesis

Photosynthesis What organisms? What organelle? Lets look closely at the structure of chloroplast PlantsChloroplast

Chloroplast Outer membrane Inner membrane Thylakoid (coin-shaped, membrane enclosed compartment) Granum (pl. grana) stack of thylakoids Stroma (fluid outside thylakoids) Draw and label picture in your notebook

Add to your notes CHLOROPHYLL Pigment molecule responsible for sunlight absorption Chlorophyll is found on the thylakoid membranes of chloroplasts The main types are: chlorophyll a and chlorophyll b Together they absorbs mostly red and blue wavelenghts (think of a rainbow) Green wavelengths are being reflected (that’s why plants look green)

Pair Share 1 2 4)4) 5 3 Name all parts of chloroplast and answer question. What is the name of pigment molecule and where is it found?

Outer membrane Inner membrane Thylakoid (coin-shaped, membrane enclosed compartment) Granum (pl. grana) stack of thylakoids Stroma (fluid outside thylakoids) Pair Share Name all parts of chloroplast and answer question. What is the name of pigment molecule and where is it found? Chlorophyll and it’s located on thylakoid membranes.

Process of PHOTOSYNTHESIS Photosynthesis is complicated process involving variety of molecules and enzymes It can be summarized as: 6 CO2 + 6 H2O + sunlight energy C6H12O6 + 6 O2 Carbon dioxide + water + sunlight energy glucose + oxygen 2 steps: 1.Light-dependent reactions (happens in thylakoids) 2.Light-independent reactions (happens in stroma)

Light-dependent Where? Thylakoids What is needed? Sunlight energy Water Chlorophyll Steps: Chlorophyll absorbs sunlight energy Water molecule is broken down Oxygen is released Energy carried along thylakoid membrane is transferred to molecules that carry energy (ATP) At the end of the light-dependent reactions we have energy-rich carriers (ATP) and released free oxygen.

Light-independent Where? Stroma What is needed? Chemical energy from light dependent reaction (ATP) Carbon dioxide Steps: In order to build larger carbon molecules, carbon dioxide molecules are added together in a cycle of chemical reactions. Energy from light dependent reaction is used. Molecule of simple sugar (glucose) is formed. At the end of the light-independent reactions we have glucose molecule which serves as a storage of chemical energy.

Compare Light dependent (need chlorophyll) Light-independent (can happen at night) Water Oxygen Molecules that carry energy (ATP) Carbon dioxide GLUCOSE Stores chemical energy

Pair share Fill in the blanks

Pair share Light dependent (need chlorophyll) Light-independent (can happen at night) Water Oxygen Molecules that carry energy (ATP) Carbon dioxide GLUCOSE Stores chemical energy 9 - Stroma 10 - thylakoids