CHLOROPLASTS - chloroplasts hydrogen ions are pumped into...

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CHLOROPLASTS Chloroplasts are the organelles responsible for photosynthesis and function to generate metabolic energy. Structural characteristics: o They have a double membrane around the outside and have an additional thylakoid membrane that can for stacks of disks called grana. ( Diagram ) o They have their own genetic material and perform protein synthesis o They synthesize their own fatty acids, amino acids, and lipid components o They reduce nitrite (NO 2 - ) to ammonia (NH 3 ). Chloroplasts have three distince internal compartments o The space between the two outer membranes o The stroma within the double unit membrane but outside the thylakoids o The space within the thylakoids Like mitochondria the outer membrane contains porins and is permeable to small molecules while the inner membrane is very restrictive. Unlike the mitochondria, the electron transport and energy production of chloroplast is located in the thylakoids instead of the inner membrane. In
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Unformatted text preview: chloroplasts hydrogen ions are pumped into the thylakoid during photosynthesis and ATP is generated as these ions pass out into the stoma. Like mitochondria, chloroplasts contain their own genetic material, perhaps reflecting their evolutionary origins as photosynthetic bacteria. The chloroplast genome is much larger, 120 - 160 kbp, and codes for about 120 genes. About 90% of choroplast proteins are encoded by nuclear genes and are transported from the cytoplasm of the cell into the chloroplast via signal peptides. Other Plastids Chromoplasts lack chlorophyll but contain carotenoids and other pigments and are responsible for the color of flowers and fruits. Leucoplasts are nonpigmented plasteds which sore energy sources in nonphotosynthetic tissue. o Amyloplasts are Leucoplasts that store starch. o Elaioplasts are leucoplasts that store lipids....
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