Chapter 7: Using Light to Make Food Flashcards
Or, photosynthesis
Photosynthesis Equation
6CO2 + 6H2O ——-> C6H12O6 + 6O2
What Drives Light Reactions
Sunlight is a type of energy called electromagnetic energy or radiation.
Certain wavelengths of visible light are absorbed by chlorophyll and other pigments.
Carotenoids also function in photoprotection from excessive light.
The Calvin Cycle
Photoautotrophs
Plants, algae, and some photosynthetic protists and bacteria, the producers of food consumed by heterotrophic organisms.
Heterotrophs
Consumers that feed on plants or animals or decompose organic material.
Structure of Chloroplasts
-Surrounded by a double membrane
-contain stacks of thylakoids and a thick fluid called stroma.
-Chlorophyll, a light-absorbing pigment in the chloroplasts that plays a role in converting solar energy to chemical energy.
Redox Process
Photosynthesis & respiration are examples of this
-Oxidation reduction
-PS H20 is oxidized and C02 is reduced, in cell respir. harvests chem energy in glucose molecule.
Redox Reaction of Photosynthesis
energy + 6 C02 (becomes reduced) + 6H20 (becomes oxidized) ——-> C6H12O6 + 602 (becomes oxidized)
2 Stages of PHS
The light reactions occur on and inside the thylakoids, producing A T P and N A D P H for the Calvin cycle, which takes place in the stroma.
-During the Calvin Cycle, c02 is incorporated into organic compounds in a process called carbon fixation.
Photosystems
-light harvesting complexes with a reaction center complex
VIBGYOR
Visible light:
-Violet
-Indigo
-Blue
-Green
-Yellow
-Orange
-Red
What do photosystems do?
electrons shuttle from photostm1 to photostm2, providing energy to make ATP, which reduce to NADP+ to NADPH.
photostm2 regains electrons as water is split and 02 released.
Photophosphorylation
-In the thylakoid membranes
-The electron transport chain pumps H+ into the thylakoid space
-the concentration drives H+ back through ATP synthase, powering synthesis of ATP
