Photosynthesis

[Audio] Note: The picture on the left is of plant cells under a light microscope and the chloroplasts are visible as green circles. The structure of chloroplasts will be covered on slide 7..

[Audio] Note: A more in depth look at each molecule in the reaction is covered on slide 6..

These organisms are known as photoautotrophs or producers meaning they make their own food and energy from the sun..

[Audio] Note: Hippos are the most dangerous herbivore in Africa. Their powerful jaws can bite adult crocodiles in half! If you ever come across a hippo run away..

[Audio] Note: The difference between cellulose and starch since both are made up entirely of several glucose molecules is where they bond to each other. Notice in cellulose the CH2OH chain is always at the top but in starch the chain alternates top to bottom..

[Audio] ANIMATION: There is a ton of animation on this slide to help walk the students through reading chemical formulas. First – each letter stands for the element in the periodic table the atom is made of. A group of letters together (e.g. H2O) means there are two H hydrogen atoms and one O oxygen atom in each molecule. The molecules used in this equation are carbon dioxide, water, glucose, and oxygen. Second – if there is a big number before a molecule it is the number of each molecule e.g. 6 H2O means 6 water molecules and since there are 2 hydrogen atoms and 1 oxygen atom per molecule, 6 water molecules has 12 hydrogen atoms (6x2=12) and 6 oxygen atoms (6x1=6). Note: The molecules in a reaction before the conversion takes place are called "reactants" if you'd like you can change the "Before" label in the table to "Reactants." After a reaction has taken place the reactants are changed into new molecules and these are called "products" you can change the "After" label in the table to "Products." Reactants are the starting materials for a reaction and products are the ending materials at end of the reaction..

[Audio] Note: The chloroplast picture on top was taken with a light microscope with a magnification of about 100x. The bottom picture of chloroplasts was taken with an electromagnetic microscope which has a magnification range up to 10,000,00x. Emphasize the terms thylakoid and stroma as these are where the reactions take place..

[Audio] YouTube Video: Before or after covering the text on the slide click on the "Where did chloroplasts come from?" link to a great YouTube video called "Evolution and Oxygen" that is 9:29 minutes long and covers the complete history. Once the video is finished there is animation on the slide, click to make the last paragraph appear that covers one piece of evidence for the endosymbiotic theory. Note: Prokaryotes are cells without a nucleus and these include all bacteria. The difference between bacterial DNA and plant DNA is that prokaryotes do not contain their DNA in a nucleus and is free floating. Plants are eukaryotes which means their DNA is contained in a nucleus (represented by the purple circle in the slide)..

[Audio] Question for class: Cyanobacteria lack chloroplasts – why? Answer: Because the organelle chloroplasts originated from cyanobacteria that were absorbed by eukaryotic (ancestral plant) cells..

[Audio] Note: Trace through the zoomed in plant leaf diagram on the left from the leaf to thylakoids to give students a sense of where the thylakoids are in the plant and how small they are..

[Audio] Note: Remind students that dependent means "requires or needs" and independent means "stand alone or doesn't need." So light dependent reactions require or needs light to occur and the light independent reactions do not need light to take place..

[Audio] Note: When NADP+ holds the excited electron which has a negative charge it attaches to a proton, or a single Hydrogen atom with a positive charge, hence the H at the end of NADPH. Reactions we need ATP for transporting molecules across membranes, cell division, cell movement, and production of proteins..

[Audio] Note: Only one photosystem II protein complex is shown in the thylakoid membrane but there are actually many in each thylakoid membrane of each granum in every chloroplast of each plant cell so photosynthesis involves many molecules of each product..

[Audio] Note: The movement of protons across the thylakoid membrane is due to a proton concentration gradient. When particles are more crowded in one area they tend to flow away to a less crowded area. You can see this by adding a drop of food coloring to a cup of water, the dye disperses until the particles are evenly dispersed throughout so that no one area is more crowded than the other. "Crowded" is a hyperlink that leads to a YouTube video explaining exactly how proton concentration gradients are used to power ATP synthase to make ATP in the mitochondria..

NADP+. NADPH. NADPH then carries its energy over to power the dark reactions or Calvin Cycle..

[Audio] Note: YouTube hyperlink "light dependent reaction" 6:35 this video explains light dependent reactions and goes more into depth than the PowerPoint..

The Calvin Cycle starts with RuBP molecules and carbon dioxide molecules. An enzyme called R ubisco combines them into an unstable intermediate..

The left overs are reused in the light reactions to remake ATP and NADPH..

Most of the G3P made during the Calvin Cycle are made into RuBP , the starting molecule, with energy from ATP molecules. Now the Calvin Cycle can begin again..

[Audio] Note: YouTube clip link at hyperlink "The Calvin Cycle" is 7:30 minutes long and covers the light independent or dark reactions or Calvin Cycle reactions more in depth. He does misspeak at the beginning of the video and says the light independent reactions stop when there is no light but this is incorrect the light dependent reactions stop when there is no light, the light independent reactions occur in the light or dark..

[Audio] Note: YouTube hyperlink at "Summary." Video has no words, just a short video of water molecules being absorbed from roots, carbon dioxide molecules entering the stroma, and the conversion process. I would stop the video after 1:00, the first half shows the water molecules and carbon dioxide molecules entering the plants but the second half does not show the reactions happening in the thylakoids or stroma..

[Audio] Note: Oceans absorb carbon in the form of precipitation for more information see the Carbon Cycle..

Go Out and Thank a Tree!.