NOTES-chap 10

NOTES-chap 10 - Photosynthesis the conversion of light...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Photosynthesis - the conversion of light energy to chemical energy that is stored in glucose or other organic compounds; occurs in plants, algae and certain prokaryotes. organisms acquire organic compounds it uses for energy and carbon skeletons by one of two major methods: 1. Autotrophic - taking in resources from their environment. Autotrophs: producers of the biosphere (global ecosystem) . not totally self-sufficient . self-feeders: can sustain themselves without eating other organisms derived from other organisms . produce their organic molecules from CO2 and other inorganic raw material obtained from the environment 2. Heterotrophic- taking in resources by different means Heterotrophs: consumers of the biosphere . unable to make their own food . live on compounds produced by other organisms . animal eats plants or other animals . decomposers: consume remains of dead organisms- carcasses, feces, fallen leaves . dependent on photoautotrophs for food, and also for oxygen Chloroplasts- the site of photosynthesis in plants Chlorophyll - the green pigment located within the chloroplasts . absorbs light energy that drives synthesis of food molecules . resides in thylakoid membranes Mesophyl – the tissue in the interior of the leaf . common location for chloroplasts . 30-40 chloroplasts Stomata - means by which CO2 enters the leaf and oxygen exits (photosynthetic prokaryotes lack chloroplasts) Photosynthesis can be summarized by this equation: in the presence of light, the green parts of the plants produce organic compounds and oxygen from carbon dioxide and water 6CO2 + 12H2O + light energy C6H12O6 + 6O2 + 6H2O Water appears on both sides because 12 molecules are consumes, and 6 molecules are newly formed Net equation: 6CO2 + 6H2O + light energy C6H12O6 + 6O2 . reverse of what occurs during cellular respiration, however, plants do not make food by simply reversing the process Simplest form of equation (divided by 6): CO2 + H2O CH2O + O2
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Discovery that chloroplast splits water into hydrogen and oxygen affirmed mechanism of photosynthesis Van Niel reasoned that bacteria split H2S and use the hydrogen to make sugar. Similarily, plants use water to harvest the hydrogen to make sugar. Generally, all photosynthetic organisms require a hydrogen source, but that source varies: general- CO2 + 2H2X CH2O + H2O + 2X Sulfur bacteria- CO2 + 2H2S CH2O + H20 + 2S Plants: CO2 + 2H2S CH2O + H2O + O2 . thus plants split water as a source of hydrogen, releasing oxygen as a by-product . most important result of shuffling atoms during photosynthesis is the extraction of hydrogen from water and its incorporation into sugar. . the waste product of photosynthesis, O2, restores the atmospheric oxygen consumed during cellular respiration. Photosynthesis as a redox process
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 7

NOTES-chap 10 - Photosynthesis the conversion of light...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online