| A | B |
|---|
| cell or plain membrane | giver shape, controls types of molecules entering and leaving, holds cells together |
| selectively permeable membrane | allowing same substances to pass through and not others |
| structure | double layer of lipid molecules with proteins embedded |
| phospholipid | head of lipid molecule - polar- carboxyl group - hydrophillic |
| molecule that forms the bilayer of the cell's membranes; has a polar, hydrophilic head bonded to _________ | two nonpolar, hydrophobic tails |
| steroid | type of lipid molecule having a complex of four carbon rings - e.g. cholesterol., estrogen, progesterone and testosterone. |
| steroids fit between tails and major (cholesterol) is found in | animals |
| peripheral proteins | located on both surfaces |
| intergral proteins | embedded in bilayer |
| integral | exposed to external environment |
| function of integral proteins | hold adjoining cells together or act as (can't read word) where viruses or chemical messengers |
| protein | transporting molecules |
| cell membrane of protein | fluid mosaic model lipids behave like fluid - lipids and proteins move laterally - pattern or mosaic is changed |
| nucleus | control center for all cell activity |
| hereditary | info is stored - RNA is made |
| nucleoplasm | protein rich protoplasm - contains chromatin - nucleic acids (DNA) and proteins |
| cell division | chromatin thickens and becomes chromosomes - carriers of hereditary messages in cells (DNA) |
| nuclear matrix | helps maintain shape - protein skeleton |
| nuclear membrane/envelope | double membrane of lipid and protein - separates nuclear material from cytoplasm |
| nuclear pores | small holes in envelope - RNA and ribosomes move through |
| nucleoli | spherical area - ribosomes synthesized |
| cytoplasm | between cell membrane and nucleus - contains organelles |
| cytosol | gelatin-like aqueous fluid surrounding organelles - salts, minerals and organic molecules are dissolved |
| organelles | "little organ" performing a specific activity |
| endoplasmic reticulum (ER) | system of tunnels - intracellular highway |
| rough ER - | large number of ribosomes attached - transports protein |
| smooth ER - | few ribosomes attached - synthesis of steroids in glands, regulation of CA + levels in muscle and breakdown of toxins in liver |
| ribosomes | most numerous - no membrane - 2 organic compounds - proteins and RNA made in nucleus |
| free ribosomes are attached ______________ | ER - proteins inserted into membranes or exported from cell |
| free ribosome function | protein factories |
