Chapter 10.2.1 (Exam 2) Photosynthesis Flashcards
Photosynthesis Converts Light Energy into Chemical Energy
What are pigments?
Molecules that absorb specific wavelengths in the visible range
Other wavelengths are scattered or transmitted, which imparts the colors we see
What is the function of the pigment chlorophyll?
Chlorophyll absorbs blue and red light and scatters green
What is the major pigment involved in photosynthesis?
Chlorophyll
Describe the structure and orientation of chlorophyll.
It has a hydrocarbon “tail” that anchors it in a protein complex in the thylakoid membrane called a photosystem
What other pigments are present in photosystems?
chlorophyll b, carotenoids, and phycobilins
What is the name of the structure within a photosystem where pigment molecules are arranged to capture and transfer light energy?
light-harvesting complexes/antenna systems
Describe the structure of a photosystem.
Several light-harvesting complexes surround a reaction center in the photosystem
How does light reach the reaction centers of photosystems?
Light energy is captured in light harvesting complexes and transferred to reaction centers
What happens in the reaction center?
Light energy is converted to chemical energy
The ground state chlorophyll enters an excited state because of energy from sunlight
What happens to the excited chlorophyll a molecule (Chl*)?
It gives up an electron (gets oxidized)
What happens when the excited chlorophyll a molecule gets oxidized?
The electron acceptor molecule gets reduced
The electron acceptor is the first in a chain of carriers in the thylakoid membrane
What is the final electron acceptor in photosynthesis?
The final electron acceptor is NADP+, which gets reduced
