Photosynthesis Endothermic reaction: Reaction that absorbs energy (sunlight) Who: Producers/Autotrophs (Plants, algae, bacteria ) Where: Chloroplasts 1)Granum (pl. Grana) – Stacks of disked shaped structures called thylakoids that house chlorophyll 2)Stroma – Fluid that surrounds the grana. – Similar to the cell’s cytoplasm Defined: Process that captures solar energy to make sugars End Result: Sugar & oxygen as waste

Light Absorption Sun gives off visible light –Red, Orange, Yellow, Green, Blue, Indigo, Violet We see reflected light –Red objects = reflect red light –Blue objects = reflect blue light

White lightPrism

Which color(s) are being reflected? Yellow Which color(s) are being absorbed? Red, Orange, Green, Blue, Indigo, Violet

Which color(s) are being reflected? Blue Which color(s) are being absorbed? Red, Orange, Yellow, Green, Indigo, Violet

Which color(s) are being reflected? None…Black is the absence of light Which color(s) are being absorbed? All….ROYGBIV

Which color(s) are being reflected? All…ROYGBIV Which color(s) are being absorbed? None

Which color(s) are being reflected? Green Which color(s) are being absorbed? Red, Orange, Yellow, Blue, Indigo, Violet

Light Absorption With leaves, green light reflected –That’s why leaves look green –Green light not used by plants Reds and blues most used in photosynthesis Green reflected Red, Orange, Yellow, Blue, Violet absorbed into the leaf

Where: Thylakoid membranes of chloroplast What happens? 1) Sunlight converted into ATP energy 2) Water (H 2 O) broken apart Hydrogen kept for later use; Oxygen is released as a waste End result: ATP (transferred to the light-independent rxns), H 2, Oxygen Stage 1: Light Dependent (Light Reactions) H2H2 O ATP H2H2 O H2H2 O H2H2 O H2H2 O H2H2 O Thylakoid Membrane

Stage 1: Light Dependent (Light Reactions) What is used during the light dependent stage? What is created during the light dependent stage?

Where: Stroma (fluid interior) of chloroplast What happens? –CO 2 taken in –ATP breaks apart CO 2 + H2H2 –C’s, O’s, and H’s recombine into C 6 H 12 O 6 (Glucose) Stage 2: Light Independent (Dark Reactions) ATP H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 CO 2 ATP H HH HH H H HH H H H C C C C C C OO O O OO OO OO OO C 6 H 12 O 6

Stage 2: Light Independent (Dark Reactions) What is used during the light independent stage? What is created during the light independent stage?

The equation for the overall process of photosynthesis : 6CO 2 + 6H 2 O  C 6 H 12 O 6 + 6O 2 C 6 H 12 O 6 Granum (stack of thylakoids) Thylakoid Sunlight = 1 six-carbon sugar 6H 2 O 6CO 2 6O 2 Chloroplast energy Stroma (fluid outside the thylakoids)

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

Connection between photosynthesis & respiration In Animals –Plants create glucose through photosynthesis –Animals eat the plants –Glucose is used to make ATP through cellular respiration Plant Cell glucose chloroplast Glucose Animal Cell mitochondria 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.What is a producer/autotroph? 4.What is used during the light dependent reactions? 5.What created during the light dependent reactions? 6.What is used during the light independent reactions? 7.What created during the light independent reactions? 8.True or False: Plants are the only photosynthetic organisms.