Biol 235: Chapter 3 (A+ Graded already)

Define Cell correct answers Living structural and functional units enclosed by a membrane Cell Biology correct answers Study of cellular structure and function 3 major components of a cell correct answers Plasma Membrane, Cytoplasm, Nucleus Plasma Membrane correct answers Forms cell's flexible outer surface separating internal and external environment Regulates flow in and out of cell Plays role in communication among and between cells and external environment Cytoplasm correct answers Cellular contents between membrane and nucleus has 2 parts 1) Cytosol -- fluid portion; contains H2O, dissolved solutes, and suspended particles 2) Organelles -- within cytosol Nucleus correct answers House's cell DNA Lipid Bilayer correct answers 2 back to back layers made up of 3 types of lipids 1) phospholipids (75%) 2) Cholesterol (20%) 3) Glycolipids (5%) Occurs because lipids are amphipathic -- polar and non polar molecules and have hydrophobic centers Cholesterol are weakly amphipathic Integral Membrane Proteins correct answers extends into or through lipid bilayer among fatty acid; tails are embedded -Most are transmembrane proteins -Some are attached to 1 side of the bilayer by covalent bonding to fatty acids -Amphiphatic Peripheral Membrane Proteins correct answers Attached to polar heads of lipids or integral proteins @ inner and outer surface Glycoproteins correct answers Integral -Have carbohydrate group attached at the ends that protrude into Extracellular Fluid ---Carbohydrates are oligosaccharides chains of 2-60 monosaccharides that may be straight or branched --- Carbohydrate portions of glycolipids and glycoproteins form sugary coat called glycolax Glycolax correct answers acts as molecular signature that enables cells to recognize one another Enables cells to adhere to one another in some tissues Protects cells from being digested by enzymes in Extracellular Fluid Hydrophilic properties attract fluid to surface -- makes Red Blood Cells slippery