PLANT PHOTOSYNTHESIS

Photosynthesis Lab

Below is a listing which will help you to prepare for the quiz and lab on this material.

I. Autotrophs & Heterotrophs –

Photosynthetic autotrophs – plants & algae (autotrophs = self feeders)

Chemosynthetic autotrophs – bacteria

• Obtain their energy from stripping electrons from inorganic sulfur & nitrogen compounds

Heterotrophs – “other feeders”

• Obtain carbon and energy from organic compounds assembled by autotrophs • Ex: all organisms which are not autotrophs; animals & fungi, etc

II. Photosynthesis Overview –

2 major parts: A. Light Dependent reactions – “light reactions” (photo portion of photosynthesis)

• These reactions capture and convert the sun’s energy into chemical energy in the form of ATP & NADPH

• Consists of CYCLIC and NON-CYCLIC PHOTOPHOSPHORYLATION

Click Here for an IMAGE of photosynthesis-

B. Light Independent Reactions – “dark rxns” aka: the Calvin-Benson Cycle

1. The energy captured in the light rxns. is used to build sugars 2. This is the biosynthesis portion

o The ATP and NADPH from the light reactions are used to build the

sugar o ATP provides the energy o NADPH provides electrons and H+

http://www.palmbeachstate.edu/faculty/allenc/bio/photo.gif
III. Balanced Equation for Photosynthesis –

12H2O + 6CO2 ——-> C6H12O6 + 6O2 + 6H2O reactants products

IV. Chloroplasts & Pigments –

A. Chloroplasts – are the organelles in which photosynthesis occurs

B. Pigments are molecules which have the capacity to absorb photons of light energy 2. Chlorophyll

a. A pigment which absorbs blue and red wavelengths of light (reflect back the

Click Here for an IMAGE of the EM Spectrum

http://www.palmbeachstate.edu/faculty/allenc/bio/spectrum.gif