cell membrane Flashcards
what is the cell membrane?
- Outer boundary of cell the cell that separates it from other cells and from
external environment - Made up of a double layer lipid molecules and associated proteins
what is the fluid mosaic model?
mosaic = Proteins and substances such as cholesterol become embedded in the bilayer fluid = the consistency of vegetable oil at body temperature, the proteins and other substances are able to move across it
what are the functions of the cell membrane?
- physical barrier
- regulation of the passage of materials
define selectively permeable
allowing certain materials into the cell (small materials) and not allowing certain substances in (large materials)
what is the cell membrane made up of?
- bi phospholipid structure- Contains two layers (bi)
- Each phospholipid molecule contains a lipid molecule with a phosphate group
- hydrophilic head that is on the outside and a hydrophobic tail that is on the inside.
- Proteins and cholesterol molecules are embedded in the phospholipid
what is the difference between the hydrophilic head and the hydrophobic tail?
hydrophilic head
- water-loving
- on the outside
hydrophobic tail
- water-hating
- inside
what are channel proteins?
- form channel through the cell membrane to allow ions, water, and other small molecules to pass through
what are carrier proteins?
- proteins that carry materials out through the cell membrane
what does cholesterol do in the cell membrane?
Allows the cell membrane to stay fluid while at the same time keeping the cell from becoming fluid
what do proteins do in the cell membrane?
- Assist in the transport of materials through the membrane
- Channel protein
- Carrier protein
- Assist in cell identity and cell to cell communications
what do glycoproteins do in the cell membrane?
- Carbohydrates attached to a protein
- Act as receptors on the cell membrane surface
what do glycolipids do in the cell membrane?
- Provide an energy source to the cell acting as a marker for cell recognition
