Histology
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Histology - Leaderboard
Histology - Details
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16 questions
| 🇬🇧 | 🇬🇧 |
| What is the most important part of exocytosis? How does it work? | Membrane fusion. Two membranes can fuse if they are similar or contain specific fusion proteins (which recognize, binds and initiate fusion) |
| Which type of exocytosis do we have? How to they work? | Constitutive and regulated. Constiutive: a continous process, the continuously migrate towards the cell membrane and release their content. This has a very slow rate. Secretory product. Regulated: First stored in the cytoplasm, waiting for a signal (extracellular, followed by intracellular rise in Ca value in cytoplasm). It releases a large amount of secretory product in a short time, it is condensed. |
| Which types of extracellular vesicles do we have? | Microvesicles and exosomes. Microvesicles: produces by budding off from the cell membrane. These are large. Exosomes: Released by exocytosis of multivesicular bodies (large vesicle containing numerous small vesicles, variant of endosomes) . |
| What is a extracellular vesicle? And what can it participate in regulation of? | They are taken up by other cells, membrane proteins and content of vesicles influence the function of these cells. This is an important cell-cell communication mechanism and signaling. This can participate in regulation of: - Cell differentiation - Defence processes - Cell proliferation |
| What is lysosomes? How do they form? what does it contain? | Lysosomes are vesicles in which intracellular digestion takes place. They are formed by fusion of hydrolase vesicles containing digestive enzymes with vesicles containing digestive enzymes (hydrolase) with vesicles containing substances to be digested. They contain proton pump. |
| Endocytosis, what is it, and which types? | Uptake of different structure by the cell. Phagocytosis Pinocytosis - Clathrin-dependent (receptor-mediated) - Clathrin independent (regular) |
| What is clathrin | Clathrin is a protein that plays a major role in the formation of coated vesicles |
| Describe phagocytosis: | It is a endocytosis process. In Phagocytosis solid particles, structures or even whole cells are taken up. Cell membrane interacts with the particles surface and extends folds which surrounds the particle and fuse to form large vesicle (Phagosome). Cytoskeleton is nesessary in process of folding the phagosome. |
| Describe pinocytosis: | It is a endocytiosis process. It is highly selective, in this way the cell can get what it needs. Only molecules bound to specific receptors in cell membrane can be taken up. The vesicular transport recuiers involvment of coating proteins (Clathrin, COP) which form a coat around the vesicles. |
| Describe the stages in the process of pinocytosis, of clathrin-dependent | 1) Binding of ligaments to cell membrane receptors. 2) Aggregation of clathrin under the area of cell membrane 3) Endocytosis- formation of coated vesicle 4) Dissociation of ligands from receptors, retur of receptors by vesicular transport to cell membrane. 5) Early endosome moves away from cell membrane and becomes late endome. 6) Late endosome: fusion with hydrolase vesicles containing digestive enzymes- late endosome becomes lysosome 7) Digestion of ligands |
| Describe the stages in the process of clarin-independent pinocytosis: | 1) Portions of liquid are taken up 2)Cell membrane invagination which pinches off forming small vesicle (pinocytotic vesicle) Cytoskeleton is not involved. |
| What does lysosomes contain, and how do they form | Vesicles in which intracellular digestion takes place. Contain digestive enzymes (hydrolases) and digested substances. They are formed by fusion of hydrolase vesicles containing digestive enzymes with vesicles containing substances to be digested. They contain a protein pump. |
| What does lysosomes look like in a microscope? | They look like dens vesicles with structures inside |
| What is mannose residues? | It is in the formation of hydrolase vesicle. It is a process in golgi complex, where the already glycosyated enzyme will phospholylate. |
| What are the lysosomal enzymes: | 1) Nucleases 2) proteases 3) Glycosidases 4)Lipases 5) Phosphatases 6)Sulfatases 7) Phospholipases They are inactive in hydrolase vesicles, and still bound to Man-6-P receptors. |
| How are lysosomes formed? | They are formed by fusion of hydrolase vesicle with: -Vesicles formed in the process of endocytosis (phagosomes, late endosomes) -> Heterolysosomes -Autophagic vacuoles containing intracellular organelles and surrounded by ER-derived membrane -> Autolysosomes. |