BIOL 2051 - EXAM 3[1]

BIOL 2051 - EXAM 3[1] - Chapter 17- Metabolic Diversity...

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

View Full Document Right Arrow Icon
Chapter 17- Metabolic Diversity   PART I The Phototrophic Way of Life  17.1 Photosynthesis, p. 533 Phototrophs - use light as energy source 2 types of photosynthesis: Anoxygenic - no oxygen is produced Most photosynthetic bacteria are anoxygenic phototrophs Oxygenic - water is split to produce oxygen Cyanobacteria and photosynthetic  eukaryotes  (plants) are oxygenic phototrophs 17.2 Photosynthetic Pigments and Their Location within the Cell,    p. 534 Pigments of photosynthesis : Chlorophylls  in oxygenic phototrophs Bacteriochlorophylls  in anoxygenic phototrophs Located in  photosynthetic membranes  where the light reactions of photosynthesis are  carried out Photosynthetic  eukaryotes  have  chloroplasts  that contain the photosynthetic  membranes known as the  thylakoids   Since photosynthetic  prokaryotes  do not have chloroplasts, the photosynthetic  membranes are: The cytoplasmic membrane in many bacteria Chlorosomes  in green bacteria Thylakoid membranes in cyanobacteria The ultimate in low-light efficiency is found in the  chlorosome  of green sulfur bacteria  and  Chloroflexus . Can grow at  lowest light intensities of all known prokaryotes   Antenna chlorophyll  molecules harvest light and funnel energy to the  reaction center  where the conversion of light to ATP occurs Different pigments absorb different wavelengths of light There are several different chlorophylls and bacteriochlorophylls, each with a unique  absorption spectra Different species have different pigments making it easy for two organisms to coexist  in  a habitat without competing for light energy 1
Background image of page 1

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

View Full DocumentRight Arrow Icon
17.3 Carotenoids and Phycobilins, p. 537 Carotenoids  (always in phototrophic orgs) and  phycobilins  (in cyanobact and red algal  chloroplasts)- accessory pigments that absorb light and transfer the energy to reaction  center chlorophylls  Chlorophylls can only absorb certain wavelengths of light. Accessory pigments allow  organisms to capture additional wavelengths of light Phycobilins      absorb yellow (around 550nm) or red light (620, 650nm) depending on the  pigment Carotenoids      absorb blue light around 475nm Carotenoids also play an important photoprotective role in preventing photooxidative  damage (due to toxic forms of oxygen) to cells  In  photosynthesis , a series of electron transport reactions in the photosynthetic  reaction center of phototrophs results in the formation of a proton motive force and the  synthesis of ATP 17.4 Anoxygenic Photosynthesis, p. 538 Photosynthesis that does not produce oxygen Anoxygenic phototrophs    
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.

This note was uploaded on 06/25/2008 for the course BIOL 2051 taught by Professor Brininstool during the Spring '07 term at LSU.

Page1 / 41

BIOL 2051 - EXAM 3[1] - Chapter 17- Metabolic Diversity...

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