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PLASMA MEMBRANE. ORGANELLS. INCLUSIONS.
Organelles – are CONSTANT and highly DIFFERENTIATED parts of cytoplasm.
Inclusions – are TEMPORARY portions of cytoplasm.
O R G A N E L L E S :
1. Morphologically organelles are classified on 2 types:
A) MEMBRANOUS organelles (its have 1 or 2 membranes)
B) NONMEMBRANOUS organelles (its don’t have membrane).
2. Membranous organelles with one membrane are:
a) LYSOSOMES, b)SMOOTH endoplasmic reticulum (sER)
c)ROUGH endoplasmic reticulum (rER), c)GOLGI apparatus (GA), d) PEROXiSOMES.
3. Organelles with 2 membranes are: MITOCHONDRIA
4. Nonmembranous organelles are: a)RIBOSOMES, b)CENTRIOLES, c)MICROTUBULES
5. Spherical body, surrounded by 1 membrane and containing 40 hydrolases (lytic enzymes)- it is primary lysosome. When it fuses with phagosome – it is secondary lysosome. Functions: a)intracellular digestion of polymers and engulfed bacteria;
b) autolysis of cell (self-destruction).
6. 1 membrane with attached ribosomes- is rER. Funct.: synthesis of proteins (polypeptides) from aminoacides
7. If 1 membrane forms dilations (cisternae, tubules) – it is sER. Funct.: a) synthesis of polysaccharide glycogen, b) synthesis of lipids.
8. If 1 membrane forms SERIES of flattened cisternae and SECRETORY vesicles – it is GA.
Funct.: a) secretion (or exocytosis) of synthetized polymer products,
b) formation of primary lysosomes
9. Spherical body, that surrounded by 1 membrane and containing enzyme catalase – it is peroxisome. Funct.: elimination of toxic by-product hydrogen peroxide (H2O2).
10. Ribosome is composed of 2 spherical bodies : large subunit and small subunit. Subunits are formed in NUCLEOLUS. Funct.: synthesis of proteins (polypeptides) from aminoacides.
11. Centriole –is cylindrical-shaped. Wall is composed of 9 triplets of microtubules (9x3+0).
Funct.: it forms fibres of mitotic spindle during prophase.
12.Microtubule is thin cylinder with thickness 25 nm. It is composed of protein TUBULIN.
Funct.: it provide funct. of cytoskeleton.
Functionally organelles are classified on 2 types:
A) COMMON org., and B) SPECIAL org.
Common org. present in ALL cells of ALL tissues (Its are all from enumerated above).
13.Organelles, which locate NOT in all cells and tissues – are SPECIAL organelles.
It are CILIA (in epithelium of bronchi) and FLAGELLA (in spermatozoa). Each from both inside contains AXONEME. Axoneme contains 9 pairs of peripheral microtubules+1 central pair (9x2+2). Pairs attached to each other by protein DINEIN. Funct.: motility. If due to mutation dinein is absent, cilia and flagella become NONMOTILE.
14. I N C L U S I O N S (INC.) are classified on :
a) Trophic INC. It are lipid and glycogen droplets in cytoplasm. Funct.: it are origin of energy.
b) Secretory INC. It are sinthetized hormones and enzymes for following exocytosis. Form of it accumulation is SECRETORY GRANULES.
c) Pigment INC. It is brown pigment MELANIN in skin cells, red pigment hemoglobin in RBCs.
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