Photosynthesis Short Answer Practice

#1 What makes chlorophyll so unique? Made of photon-absorbing porphyrin ring with Mg in center Nitrogen atoms around the Mg Photon of light resonates the e- between the single and double bonds

#1 What makes chlorophyll so unique? Hydrocarbon tail Attaches to Integral protein in the Thylakoid disk membrane

#2 Compare PSII and PSI Both absorb photons and excite e- Both contain chlor a + other pigments Reaction center of PSII absorbs 680 nm Reaction center of PS I absorbs 700 nm PSII receives e- from split water PS I receives e- from Pc (end of ETC)

#2 Compare PSII and PSI PSII PSI -PSII gives electrons to ETC -PSI give electrons to NADP+ PSII PSI FOUND IN THYLAKOID DISK MEMBRANE

#3Compare chemiosmosis and ETC in mitochondrion and chloroplast: e- come from food molecules e- have high potential energy in bonds in organic compounds e- passed to oxygen Oxygen pick up H+ to form H2O Chloroplast e- come from splitting of H2O Light energy excites e- to a higher energy level e- flow from H2O to reaction center 680 in PSII to reaction center 700 in PSI From PSI to NDR to reduce NADP+ to NADPH

#4 CFC’s Chlorofluorocarbons Were put in aerosols, refrigerants, and styrofoam Products containing CFC’s were Banned by those signing the Montreal Protocol 1987 Recovery of ozone not expected until 2060’s.

Ozone O3 O3 (seen in teal blue in diagram) Protective layer around the earth keeping harmful UV rays from reaching the earth UV rays (some enter, some blocked) Infrared (trapped)

#4 CFC’s Cl breaks off an oxygen from ozone (O3) so it is no longer a protective layer around the earth.

Global Warming refers to the rising average temperature of Earth's atmosphere and oceans

Greenhouse Gases CO2 (carbon dioxide) – most important! H2O (water vapor) CH4 (methane) CFC’s (chlorofluorocarbons) These can absorb heat and warm the atmosphere.

Causes and Effects of Global Warming Increase in greenhouse gases: especially CO2 (mostly from fossil fuel emissions) -Kills coral reefs -Melts polar icecaps -Raises ocean levels -Upsets weather

CFC’s and Global Warming

#4 Global Warming Solutions Photosynthesis removes CO2 from the atmosphere Reduce fossil fuel use (CO2 is an important global warming gas -absorbs heat) Use alternate energy sources (wind, solar, geothermal, hydroelectric)