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11 Cards in this Set
- Front
- Back
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The Nucleus
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THE CELL'S CONTROL CENTER:
• The nucleus is the command and control center of the cell it also stores hereditary information ____________ • The nuclear surface is bounded by a double membrane (lining, boundary) called the nuclear envelope -groups of proteins form openings called nuclear pores that permit proteins and RNA to pass in and out of the nucleus |
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The Nucleus 2
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• The DNA of eukaryotes is packaged into
sections and associated with a protein -this complex is called a chromosome • the proteins enable the DNA to be wound tightly so it appears condensed – the condensed or chromosome form of DNA occurs during cell division • the DNA is uncoiled into strands called chromatin that are no longer visible as segments – protein synthesis occurs when the DNA is in the chromatin form |
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The Nucleus 3
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• The nucleus is the site for the subunits of
the ribosome to be synthesized -the nucleolus is a dark-staining region of the nucleus • it contains the genes that code for the rRNA (ribosomal RNA) that makes up the ribosomal subunits • the subunits leave the nucleus via the nuclear pores and the final ribosome is assembled in the cytoplasm |
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The Endomembrane System
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An extensive system of internal
membranes organizes the interior of the cell into functional compartments. • Endoplasmic reticulum • The Golgi complex • Lysosomes • Vacuoles |
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The Endoplasmic Reticulum (ER)
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- Extensive system of internal membranes
- Some membranes create a series of channels and interconnection - Portion of ER can become isolated spaces enclosed by membranes. These space are called vesicles |
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The Endoplasmic Reticulum (ER) 2
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• The Endoplasmic Reticulum (ER) required
for synthesis and transport of material • The segment of the ER dedicated to protein synthesis is called the rough ER (Larger Crevaces) - the surface of this region looks rough under microscope - the rough spots are due to embedded ribosomes • The segment of the ER that aids in the manufacture of carbohydrates and lipids is called the smooth ER (smaller crevaces) - the surface of this region looks smooth because it contains no embedded ribosomes |
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The Golgi Complex
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The Golgi Complex
• After synthesis in the ER, the newly-made molecules are passed to the Golgi bodies - Golgi bodies are flattened membranes that form collective stacks called the Golgi complex (Golgi Apparatus) - their numbers vary depending on the cell - their function is to collect, package, and distribute molecules manufactured in the cell |
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ER and Golgi Complex...
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The Endomembrane System
• The ER and Golgi complex function together as a transport system in the cell How the endomembrane system works Protein and lipids manufactured on the ER membranes are transported through the ER and are packaged into transport vesicles that bud off from the ER The transport vesicles fuse with membrane of the Golgi bodies the content goes into the Golgi The molecules are modified and distributed to different cell compartment secreted |
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Lysosomes
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Lysosomes
• The Golgi complex also gives rise to lysosomes - these membrane-bound structures contain enzymes that the cell uses to break down macromolecules • worn-out cell parts are broken down and their components recycled to form new parts • particles that the cell has ingested are also digested |
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Vacuoles
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• Plants and many protist contain vacuoles
-These membrane-bound structures contain • Water • Sugar • Ions • Pigment -Function as a storage compartment |
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Organelles That contain DNA
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Eukaryotic cells contain cell-like organelles
that, besides the nucleus, also contain DNA - these organelles appear to have been derived from ancient bacteria that were then assimilated by the eukaryotic cell -they include the following organelles: mitochondria and chloroplasts |
