Obtaining Energy Autotrophs – auto – troph – - make their own food Heterotrophs – hetero – - eat other organisms to obtain energy

Chemoautotrophs – make food using chemicals instead of sunlight (found in hot springs and in the deepest parts of the ocean) (Almost) All energy ultimately comes from the sun, nearly all life on earth relies on plants to turn the sun’s energy into a usable form.

Where does nearly all energy ultimately come from?Where does nearly all energy ultimately come from? What is a heterotroph?What is a heterotroph? –Give an example.

Ingredients for Photosynthesis Water – enters plants through the roots Sunlight – captured by the thylakoid membranes in the chloroplast Carbon dioxide – (CO 2 )enters the leaf through the stoma (pores)

Products of Photosynthesis Oxygen (O 2 ) – released as a waste product Glucose (C 6 H 12 O 6 ) – carbohydrate used for food

Tell the 3 ingredients of photosynthesis.Tell the 3 ingredients of photosynthesis. Tell the 2 products of photosynthesis.Tell the 2 products of photosynthesis.

Formula for Photosynthesis 6CO 2 + 6H 2 O light C 6 H 12 O 6 + 6O 2 Notice, ingredients go on the left, products go on the right. The arrow is like an equal sign. If energy needs to be added to a reaction for it to occur, it goes above the arrow.

Why is light written above the arrow in the formula?Why is light written above the arrow in the formula?

Chloroplasts Chloroplast are green due to a green pigment called chlorophyll which absorbs the light. Each chloroplast is filled with stacks of thylakoids.

Steps of Photosynthesis Phase 1 – Light Reaction 1.Light hits the thylakoid membrane in the chloroplast. 2.Light energy breaks water into H +, e -, and O. 2H 2 O light 4e - + 4H + + O 2 3.Electrons and protons (H + ) travel along the electron transport chain to turn NADP + into NADPH and ADP into ATP. (This is like recharging dead rechargeable batteries.)

Phase 2 – Calvin Cycle 4. CO 2 enters the leaf through the stoma. 5. ATP and NADPH give up their energy to CO 2 and H + from NADPH to produce C 6 H 12 O Oxygen is released.

What are the 2 phases of photosynthesis?What are the 2 phases of photosynthesis? Describe each phase to your partner.Describe each phase to your partner.

ATP and NADPH aren’t stable enough to store energy long term, which is why energy is stored as glucose. Glucose stores energy much more efficiently than ATP or NADPH.

Why is energy stored as glucose rather than ATP or NADPH?Why is energy stored as glucose rather than ATP or NADPH?