Topic 3: cellular level of organization Flashcards
what is the cell?
-basic structural and functional unit of the body
-can perform all basic life functions
what are the names of the outermost part of the cell?
-cell membrane
-plasma mebrane
-plasmalemma
what is the cell membrane composed of?
-phospholipid bilayer
-cholesterol
-membrane proteins
-membrane carbohydrates
-microvilli
what does the phospholipid bilayer divide?
-the intracellular fluid and the extracellular fluid
what is intracellular fluid?
-fluid inside the cell
what is extracellular fluid
-fluid outside the cell
what are the two types of membrane proteins?
-integral proteins
-peripheral proteins
what are integral proteins?
-integrated within the membrane
-they have a hydrophobic region to interact with the fatty acid tails
-those that extend across the entire membrane are called transmembrane proteins
what are peripheral proteins?
-attached to the surface of the membrane
-also can be attached to the surface of an integral protein
what are the functions of membrane proteins?
-enzymes
-transporters (ATP)
-channels (NO ATP)
-receptors (HORMONES)
-anchors
-identity markers (for the immune system)
what are membrane carbohydrates?
-only on the outer surface
-bound to other proteins (glycoproteins) or lipids (glycolipids)
-used for cell recognition (sperm recognizing an egg)
-anchor cells together
what is cholesterols purpose in the membrane?
-they are scattered throughout the membrane
-add stability + fluidity
-doesn’t break apart at extreme temps
what is the phospholipid bilayer composed of?
-phosphate head group (hydrophilic)
-fatty acid tails (hydrophobic)
-double layered
-heads on the outer side, tails on the inner
what are microvilli?
-small projections of the cell membrane
-used to increase surface area (increased absorption)
they are best seem on small intestine cells and kidney cells
what is the fluid mosaic model?
-shows the phospholipid bilayer
-shows membrane proteins
-fluid - components can move (phospholipids + some proteins)
-mosaic - proteins dot the surface
what is the cytoplasm?
- an AREA (not a fluid)
-area between the inside of the cell membrane and the outside of the nucleus
what are the two divisions of the cytoplasm?
-cytosol
-organelles