Grant Lahring, Friday, November 12, 2009 (3/3)

What We Did Today

• Wrote cellular respiration test
• Went over notes on photosynthesis
• Learned about photosystems and the electromagnetic spectrum
• Reviewed chloroplasts from grade 10

My Thoughts

• I learned a lot about photosythesis, which part of the reaction requires light, that there are two different photosystems on the thylakoid membrane and each absorbs a different wavelenght of light.
• Like cellular respiration, photosynthesis is really hard to learn solely through notes.
• That photosynthesis also produces ATP, in much the same way as CR. I thought PS was for making glucose for CR to burn, and I guess it is, but it makes some of it's own energy.

Above and Beyond

• One of the questions we began the year with was how does photosynthesis use light? In class we discussed that the light excites an electron to jump an energy level, but that seems like we have to take it on faith, as does a lot of these processes. The method we learn seems to ignore parts of the process (understandable, as they are hard enough as is)
• To remedy this lack of knowledge I went to my dad's old university textbook. After fifteen minutes of staring blankly at a page depicting chloropyll A I have decided ignorance is a lot simpler.
• I learned which energy levels each pigment in a leaf absorbs, which is as follows;

• Chlorophyll A - occurs in all green plants - Absorbs red and violet-blue light
• Chlorophyll B - Green plants, not red or blue-green algae - Absorbs red and violet-blue light
• Chlorophyll C - Brown algae and diatoms - Absorbs red and violet-blue light
• Chlorophyll D - Red algae - Absorbs red and violet-blue light
• Protochlorophyll - Etiolated plants - Near red and blue-violet
• Bacteriochlophyll - Purple bacteria -   "       "     "      "  -  "
• Bacterioviridin - Green sulfur bacteria - "      "     "      "  -  "
• Phycocyanin - Blue green or red algae - Orange red
• Phycoerythrin - Blue green or red algae - Green
• Carotenoids - Most plants, bacteria - Blue, blue-green

Sorry, I can't get a picture for this entry because I'm on dial-up and something is wrong with my computer (random freezes and resets, etc)