What is ATP?
• Where does the energy come from?
• Why is it important?
• ATP = adenosine triphosphate
• Bonds between phosphates hold energy
• It is recycled
– It acts like a credit card  once it is used, it will be
recharged
• http://www.youtube.com/watch?v=4S6X7qaLjvk
(What is ATP? – Bill Nye)
• https://www.youtube.com/watch?v=bbtqF9q_pFw
Chloroplast
• Organelle that performs photosynthesis
• In plants, algae, and cyanobacteria
• http://www.youtube.com/watch?v=LTglday5zak
(chloroplast movement)
Chloroplast and Leaf
• Chloroplast
– Double-membrane bound
organelle
– Has phospholipid bilayer
• Palisade layer
– Inner layer
– Mesophyll – green tissue
inside the leaf; contains
chloroplasts
– Xylem (water movement)
– Phloem (sugar + molecule
movement)
• Epidermis
– Outer layer
– Contains plant’s pores and
cuticle
Parts of the Chloroplast
• Stroma – thick fluid in the inner membrane of
chloroplast; used for sugar production (dark
reactions)
• Thylakoid – stacks of membranes; site of sunlight
absorption (light reactions)
• Lumen – space inside of the thylakoid
• Granum – stacks of thylakoids
• Inner and outer membranes
Controlling Water Loss
• What can plants do to reduce water loss?
• What might be a difference between how a plant
can control water loss in a desert versus a forest?
• Transpiration = water loss
– Leaves contain stomata and guard cells
• They open and close
Parts of the Leaf
• Stomata – tiny pores and
specialized cells in the leaf
that allow for gas exchange
– Stoma = “mouth” or pore
itself
• CO2 goes in
• O2 comes out
– Guard cells – change shape to
open or close the stoma
• https://www.youtube.com/
watch?v=Br4gJuQslMI
(guard cell animation)
Guard Cells and Stomata