Chlorophyll, more like borophyll!

Energy-essential to life -what is it used for?

Photosynthesis Equation

Biochemical Pathway-series of chemical reactions in which the product of one reaction is consumed in the next reaction

Cross Section of Leaf

1st Step of Photosynthesis is the Light Reactions -this is where light is absorbed by the chloroplasts

Paper Chromatography http://images.google.com/imgres?imgurl=http://www.yorktown.k12.in.us/yhs/teachers/clucas/bintroductionand%2520labsafety_files/paper%2520chromatography.jpg&imgrefurl=http://www.yorktown.k12.in.us/yhs/teachers/clucas/bintroductionand%2520labsafety.htm&h=377&w=381&sz=30&hl=en&start=3&tbnid=cRmZ19VVd3BJ6M:&tbnh=122&tbnw=123&prev=/images%3Fq%3Dpaper%2Bchromatography%26svnum%3D10%26hl%3Den%26lr%3D%26safe%3Dactive

Spinach Chromatography http://genchem.chem.wisc.edu/demonstrations/Images/01mattermix/spinach.jpg

The Light Reactions

Chemiosmosis -depends on a concentration gradient of protons across the thylakoid membrane -high concentration inside thylakoid, low concentration in the stroma -uses a protein called ATP synthase in the thylakoid membrane

Chemiosmosis and the ATP Synthase

Applications Many herbicides work by inhibiting photosynthesis by blocking the electron transport in photosystem II Rising CO2 levels from industry-will this have an impact on plant growth?

Big Picture for the Light Reactions -to make energy (ATP, NADPH) to be used in the dark reactions

The Dark Reactions (Light Independent Reactions) -Can take place at night or when there is no light -Use energy from the light reactions (ATP, NADPH) to run the Calvin Benson Cycle

The dark reactions include the Calvin Benson Cycle where: Carbon atoms from CO2 are "fixed" into organic compounds (food), and the process is called carbon fixation

Alternative Pathways for Carbon Fixation

The Calvin Cycle is the most common pathway for plants to "fix" carbon, and these plants are called C3 plants

Stomata-small pores usually on the undersurface of leaves, where water, O2, and CO2 pass in and out of plant

Examples: corn, sugar cane, crabgrass C4 Pathway-fix CO2 into four-carbon compounds, during hot part of day, they keep their stomata closed Examples: corn, sugar cane, crabgrass http://images.google.com/images?q=crabgrass&svnum=10&hl=en&lr=&safe=active&start=20&sa=N&ndsp=20 http://www.seco.cpa.state.tx.us/Images/re_bio-sugarcane.jpg

CAM Pathway-open stomata at night and close them during the day, why? Examples: cactuses, pineapples, plants in hot, dry environments http://helios.bto.ed.ac.uk/bto/desbiome/saguarox.jpg

The Structure of a Leaf · Label the cross-section of a leaf submitted by Joe Scrivens · Label the cross-section of a leaf · Understand the functions of different structures in a leaf

Match the structures to their functions This layer contains palisade cells and is where most of photosynthesis occurs. This layer has many air spaces. These cells make wax which covers the top of the leaf and makes water resistant. Click here to check your answers. cuticle palisade layer spongy mesophyll

Match the structures to their functions This is where air enters and leaves the leaf. These cells close and open the stomata. This transports water and minerals This transports the products of photosynthesis. Click here to check your answers. guard cells phloem stomata xylem

Answer to the task on page 4 Structure Function palisade layer This layer contains palisade cells and is where most of photosynthesis occurs. This layer has many air spaces These cells make wax which covers the top of the leaf and makes it water resistant. spongy mesophyll cuticle Click here to go back.

Answer to the task on page 5 Structure Function This is where air enters and leaves the leaf. These cells close and open the stomata. This transports water and minerals. This transports the products of photosynthesis. stomata guard cells xylem phloem Click here to go back.