- Mitochondria: produce energy
("powerhouse") (in eucaryotic cells only)
- Outer membrane (not folded)
- Outer compartment between the membranes, into which H+ ions are pumped
- Inner membrane (highly folded); folds are called cristae
- Interior, filled with matrix containing enzymes and mitochondrial DNA
- Ribosomes, small units essential in protein synthesis.
- Each has smaller (30S) and larger (50S) subunits
- May occur alone, but often attached to endoplasmic reticulum in eucaryotes
- Cytoskeleton and tubular organelles (in eucaryotic cells only):
- Microfilaments: protein filaments (actin, myosin, etc.)
used in phagocytosis, amoeboid locomotion, muscle contraction, etc.
- Microtubules: hollow tubules of protein, important in cell motility, and
used as spindle fibers in mitosis
- Centrioles, cilia, eucaryotic flagellae: made of microtubules arranged
as nine pairs or triplets in a circle, often surrrounding two single tubules
- Plastids (in plant cells only):
- Leucoplasts: colorless plastids used in food storage
- Chloroplasts: green plastids with chlorophyll; carry out photosynthesis
Contain grana (stacks of disk-shaped thylakoids)
and stroma (spaces between the grana)
- Chromoplasts: plastids with pigments other than chlorophyll
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