Photosyntesis

What is photosynthesis?

The ability to use light to convert inorganic molecules into organicmolecules.

H2O + CO2 ==== light == sugar + O2

Sugar can then be used to make other required molecules, or it can be

Broken down as a source of energy… O2 is simply a biproduct of photo-

Synthesis… almost all the O2 in the earth’s atmosphere comes from photSynthesis.

Photosyntesis

Leaves and Chloroplasts are adaptations for photosynthesis.

Photosyntesis – light and dark reactionsPhotosynthesis has two phases:

A light dependent reaction where the energy in light is converted into chemical energy of molecules such as ATP and NADPH.

A dark reaction where the molecular energy carriers are used to build the sugar molecules.

Photosyntesis – Pigments

The first step of photosynthesis involves using pigments to capture light.

The range of visible light used for photosynthesis is from about 400 to 750 nanometer wavelengthsof electromagnetic radiation…this range is referred to as PAR –Photosynthetically Active Radiation.

Although chlorophyll is the primarypigment used by plants (it’s what makesplants green…), other pigments such ascarotenoids and phycocyanin are alsoused… why do you think this is?

Photosyntesis – Effects of varying light levels

P: photosynthesis

Pmax: maximum photosynthesis

Pg : gross photosynthesis

Pn : net photosynthesis

R : respiration

IK : saturating irradiance

Respiration

H2O + CO2 ==== light == glucose (sugar) + O2

Photosynthesis:

Complete glucose metabolism through cellular respiration:

sugar + O2 ====== H2O + CO2 + chemical and heat energy

Respiration – summary

Respiration – Glycolysis

Respiration – summary

Respiration – lactate and alcohol fermentation

Respiration

NADH: Nicotinamide adeninedinucleotide

FADH2:Flavin adenine dinucleotide

Respiration – electron transport chain

Respiration – electron transport chain

Respiration – electron transport chain

Respiration - summary

Respiration – other organics besides sugars?