Light Absorption Sun gives off visible (white) light White light is actually a mixture of ROY G BIV –Red, Orange, Yellow, Green, Blue, Indigo, Violet White light How do we know this?

Prism White light

Moisture in the air can act like a prism and create a RAINBOW

Light Absorption Sun gives off visible (white) light White light is actually a mixture of ROY G BIV –Red, Orange, Yellow, Green, Blue, Indigo, Violet These colors are either reflected or absorbed by objects We see reflected light –Green leaves = reflect green light

Which color(s) reflects? Yellow Which color(s) absorb? All the others I see yellow bananas. Example

Which color(s) reflects? Blue Which color(s) absorb? All the others I see a blue balloon.

I see white snow. Which color(s) reflects? All Which color(s) absorb? None

I see a black car (although I’m really seeing nothing). Which color(s) reflects? None Which color(s) absorb? All

The Full Spectrum of Energy from the Sun Our eyes can only sense this small area called “visible light”

Most plants have green leaves, which means they: –Reflect green light –Absorb other colors Energy in red and blue light most stimulates photosynthesis Light & Photosynthesis

Defined: process that converts solar energy into glucose Who: Autotrophs (Plants, algae, some bacteria & protists) What: Endothermic chemical reaction –Requires energy & MORE energy absorbed End Result: 1.Sugar (glucose) stored in plant 2.Oxygen as a waste product reactantsproducts Photosynthesis O2O2 CO 2

Where: Thylakoid membranes of chloroplast What happens? 1)Sunlight & enzymes bond ADP with P to make… ATP 2)Water (H 2 O) broken apart Hydrogen kept for later use; Oxygen is released as a waste End result: ATP, H 2, Oxygen Stage 1: Light Dependent (Light Reactions) H2H2 O H2H2 O H2H2 O H2H2 O Stroma enzymes ADP P P ATP Thylakoids

60 seconds: Discuss with your neighbor 1)Are the products of photosynthesis on the left or right of the arrow? 2)Which reactant(s) are used during the light dependent stage? 3)Which product(s) are created during the light dependent stage? reactantsproducts #2 #3

Stroma Where: Stroma (fluid interior) of chloroplast What happens? A)CO 2 taken in B)ATP & enzymes break apart CO 2 + H2 C)C’s, O’s, and H’s recombine into C 6 H 12 O 6 (Glucose) Stage 2: Light Independent (Dark Reactions) H2H2 H2H2 H2H2 H2H2 ATP CO2 H2H2 H2H2 COO CO O COO C OO COO CO O enzymes HH HHHH HH HH HH What’s the formula for glucose? C6C6 H 12 O6O6

60 seconds: Discuss with your neighbor 1)Which reactant(s) are used during the light independent stage? 2)Which product(s) are created during the light independent stage? reactantsproducts #1 #2

Connection between photosynthesis & respiration Plants –Create glucose through photosynthesis –Glucose is used to make ATP through cellular respiration Plant Cell glucose chloroplast ATP mitochondrion

Connection between photosynthesis & respiration Animals –Plants create glucose through photosynthesis –Animals eat the plants –Glucose is used to make ATP through cellular respiration Glucose mitochondrion ATP Glucose (from food)

Review 1)Which color(s) is/are absorbed by a typical red apple? 2)Which color(s) is/are reflected by a typical red apple? 3)Which color light produces the highest rates of photosynthesis? 4)What is used during the light dependent reactions? 5)What is created during the light dependent reactions? 6)What is used during the light independent reactions? 7)What is created during the light independent reactions? 8)True or False: Plants are the only photosynthetic organisms.

1)Which color(s) is/are absorbed by a typical red apple? All the colors except red 2)Which color(s) is/are reflected by a typical red apple? Red 3)Which color light produces the highest rates of photosynthesis? Blue 4)What is used during the light dependent reactions? *H 2 O | Light Energy | Enzymes | ADP | P 5)What is created during the light dependent reactions? *O 2 | H 2 | ATP (the O 2 and H 2 are created when the water splits) 6)What is used during the light independent reactions? *CO 2 | H 2 | ATP | Enzymes 7)What is created during the light independent reactions? *C 6 H 12 O 6 8)True or False: Plants are the only photosynthetic organisms. False Answers to Review

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