Capturing Free Energy Capture and Store Free Energy Autotrophs : - - PowerPoint PPT Presentation

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Apr 26, 2023 171 likes •364 views

Capturing Free Energy Capture and Store Free Energy Autotrophs : capture free energy from the physical environment Photosynthetic sunlight Chemosynthetic inorganic molecules Heterotrophs : capture free energy in carbon

SLIDE 1

Capturing Free Energy

SLIDE 2

Capture and Store Free Energy

Autotrophs: capture free energy from the

physical environment

– Photosynthetic – sunlight – Chemosynthetic – inorganic molecules

Heterotrophs: capture free energy in carbon

compounds

SLIDE 3

Chemosynthesis

SLIDE 4

Summary of Photosynthesis

SLIDE 5

Electromagnetic Spectrum

SLIDE 6

Chlorophyll a and b Absorption

SLIDE 7

Chloroplast

SLIDE 8

Summary

SLIDE 9

Photosynthesis Reaction

(another REDOX reaction)

SLIDE 10

Light Absorption by the Chlorophyll Pigments

Photosystems are embedded within the

thylakoid membranes of chloroplasts

SLIDE 11

Light Absorption by the Chlorophyll Molecules

Clusters of chlorophyll pigments called

photosystems absorb light energy (photons)

Light energy “excites” electrons of the

chlorophyll pigments

Shorter wavelengths of light have more energy

and are therefore more effective at “exciting” electrons

SLIDE 12

Light-Dependent Reactions

Chemiosmosis and Photophosphorylation

SLIDE 13

Light-Dependent Reactions (occurs within thylakoids)

During the light reactions:

Light energy splits water molecules into hydrogen

ions (H+) and oxygen gas – this is called photolysis

Two high energy compounds, ATP and NADPH, are

also produced (energy building reactions)

ATP and NADPH transfer free energy to the light-

independent reactions (Calvin Cycle)

SLIDE 14

Calvin-Benson Cycle (Light-Independent)

SLIDE 15

Calvin-Benson Cycle

(with the stroma)

During the Calvin-Benson Cycle:

“Carbon fixation” occurs – “fixing” inorganic carbon

(from CO2) into organic carbon(G3P molecules)

CO2 combines with a five-carbon sugar called RuBP

(forms an intermediate 6-carbon compound)

Energy stored in ATP and NADPH is used to convert

the temporary 6- C intermediate compound into G3P molecules

SLIDE 16

SLIDE 17

G3P molecules (End Product)

Glyceraldehyde 3-phosphate
An intermediate in photosynthesis
G3P molecules:

– Immediate food nutrient in plants – Combined to form monosaccharides (glucose) – Transported to other cells – Packaged for storage in polysaccharides (starch and cellulose)

SLIDE 18