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Cards In This Set
| Front | Back |
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What are the functions of the plasma membrane?
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Separates each cell from the
environment, permits the flow of molecules across the membrane, and contains receptors that can affect the cell’s activities |
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A nucleus or nucleoid region localizes what?
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The hereditary
material, which can be copied and read |
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The cytoplasm contains...
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Membrane systems, particles
(including ribosomes), filaments (the cytoskeleton), and a semifluid substance |
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There are basically two kinds of cells in nature
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Eukaryotic cells contain distinctive arrays of organelles
including a membrane-bound nucleus. Prokaryotic cells (bacteria & archeae) have no nucleus. The DNA is clustered in a distinct region of the cytoplasm (nucleoid). |
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What are the functions of the nucleus?
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The nucleus isolates DNA–which contains the code for
protein assembly, from the sites–ribosomes in cytoplasm, where proteins will be assembled |
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What are the functions of Nuclear envelope
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Consists of two lipid bilayers
with pores. 2. The inner surface has attachment sites for protein filaments, which anchor the DNA molecules and keep them organized. 3. The outer surface is studded with ribosomes |
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The nucleolus
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Appears as a dense, globular mass of
material within the nucleus. 2. It is a region where RNA subunits of ribosomes are prefabricated before shipment out of the nucleus. |
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Chromatin
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Refers to the total, of DNA and proteins.
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Each chromosome is a single molecule of
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DNA and its
associated proteins; it may take on different appearances depending on the events taking place within the cell |
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Nucleoplasm
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is the semifluid material inside the nucleus
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. The cytomembrane system is
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A series of organelles in which
lipids are assembled and new polypeptide chains are synthesized and modified into final proteins.Organelles form compartmentalized portions within the cytoplasm allowing reactions to be separated with respect to time (allowing proper sequencing) and space (allowing incompatible reactions to occur in close proximity). |
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The endoplasmic reticulum is
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A collection of
interconnected tubes and flattened sacs that begins at the nucleus and winds its way through the cytoplasm |
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Rough ER consists of
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Stacked, flattened sacs with
many ribosomes attached |
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Smooth ER has
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no ribosomes; it is the site of lipid
synthesis. Smooth ER is the area from which vesicles carrying proteins and lipids are budded. |
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A Golgi body consists of
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Flattened sacs–resembling a stack
of pancakes–whose edges break away as secretory vesicles. 2. Here proteins and lipids undergo final processing, sorting, and packaging. 3. Within the cytoplasm, newly formed polypeptide chains may be stockpiled in solution or may enter the cytomembrane system (ER, Golgi bodies, and vesicles). 4. Some of the proteins will be used within the cell in which they were made, others will be exported for use elsewhere |
