HSCI 100 Lecture Notes - Lecture 4: Fluid Mosaic Model, Semipermeable Membrane, Cell Membrane

• School: Simon Fraser University
• Department: Health Sciences
• Course: HSCI 100
• Professor: Nienke Van Houten

Document Summary

All living things are made up of cells. Cells cannot exceed a certain surface area to volume ratio. Thought to be the irst cells to evolve. Represented by bacteria & archaea (2 domains of life) Cell membrane: contains cell structures; receive info; movement/expansion. Fluid mosaic model o: contains cholesterol for support; carbs on proteins & lipids on outer layer, selectively permeable. Difusion random movement of molecules from a higher to lower concentration. Atp-powered pumps combine with substances & move them across membrane from l h concentration. Endocytosis transports molecules into the cell via invagination of the plasma membrane to form a vesicle membrane; requires atp. Exocytosis transports molecules outside the cell via fusion of a vesicle with the plasma membrane spilling contents out of cell; requires atp. Hypertonic solutions have more solute than inside the cell. Water lows down concentration gradient out of the cell. Hypotonic solutions have less solute than the inside of the cell.