Mahalo biology expert Mary Poffenroth tells you about the chloroplasts found in photosynthetic organisms.
Chloroplasts
Most of the living world runs on the energy provided by the sun. The transfer from solar to chemical energy happens through photosynthesis, which occurs in the organelle called chloroplast.
Past the outer membrane you will find that the chloroplast is filled with a thick fluid called "stroma." Within the stroma are large stacks called thylakoids, arranged in granum. Think of the granum as a stack of pancakes. These thylakoids are where photosynthesis takes place.http://www.youtube.com/watch?v=y8_G9olr2fA
Antennae Complexes
Embedded in the thylakoid membrane are antennae complexes which consist of pigments like chlorophyll and carotenoids, plus proteins that help bind the pigments together. They increase surface area and wavelength range the pigments can absorb.http://www.youtube.com/watch?v=y8_G9olr2fA
DNA
Both mitochondria and chloroplasts have their own DNA, completely separate from the cell. This shows evolutionary evidence that each were free-living forms in the very distant past.http://www.youtube.com/watch?v=y8_G9olr2fA
References
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Introduction to Biology 0:00
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All About Cells 0:00
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Discovery of Cells 0:00
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Cell Theory 0:00
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Prokaryotic Cells vs. Eukaryotic Cells 0:00
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Eukaryotic Cells and Animal Cells vs. Plant C... 0:00
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Osmosis vs. Diffusion 0:00
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The Nucleus 0:00
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The Plasma Membrane 0:00
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Cytoskeleton 0:00
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Mitochondria 0:00
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Endoplasmic Reticulum 0:00
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Lysosomes 0:00
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Ribosomes 0:00
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The Golgi Apparatus 0:00
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Enzymes 0:00
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Chloroplasts 0:00
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Blood Cells of the Human Body 0:00
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Stem Cells 0:00
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Classification of Living Things 0:00
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The Taxonomic Hierarchy 0:00
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Classification and Domains 0:00
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How to Read Scientific Names 0:00
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Autotrophs vs. Heterotrophs 0:00
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Trophic Levels and Producer vs. Consumer 0:00
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Angiosperms and Pollinators 0:00
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Good Bacteria vs. Bad Bacteria 0:00
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Keystone Species vs. Indicator Species 0:00
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Genetically Modified Organisms 0:00
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Ecosystems and Communities 0:00
Meet Our Experts
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Mary Poffenroth
Mary Poffenroth is an adjunct professor of biology at San Jose State University. She holds a master's degree in biological sciences from same. Apart from hosting Mahalo videos, Poffenroth writes, produces and hosts her own short films. One such film received two honorable mentions at the 2010 International Wildlife Film Festival and her videos also appear in the 2011 edition of the Wiley International college textbook. "I want to make deceptively educational videos," she says, "that will both entertain and inspire."
