BIO 210 - Chapter 3 Questions and Answers Rated A+

BIO 210 - Chapter 3 Questions and Answers Rated A+ Plasma membrane forms the outer boundary of the cell Cellular organelles each performs specific functions Nucleus contains the cell's genetic material and directs cell activities Cytoplasm the material between the plasma membrane and nucleus Main functions of cells -cell metabolism and energy release -synthesis of molecules -communication -reproduction and inheritance Plasma membrane also called the plasmolemma or cell membrane Functions of the plasma membrane -encloses and supports the cell contents -acts as a selective barrier that regulates what goes into and out of the cell -plays a role in communication between cells -separates intracellular substances from extracellular substances Intracellular inside cells Extracellular (intercellular) between cells also called interstitial fluid Lipid bilayer double layer of phospholipids with imbedded proteins Membrane proteins protein molecules that "float" among the phspholipid molecules; either embedded in or attached to the phospholipid bilayer Attachment proteins proteins that allow cells to attach to other cells Transport proteins proteins that move ions and molecules across the membrane Receptor proteins proteins that attach to chemical signals on the cell surface Enzymes proteins that catalyze chemical reactions Membrane carbohydrates carbs that act as a marker molecules on the cell surface and allow cells to identify "self" versus "non-self" Glycoproteins proteins attached to carbohydrates on the cell surface Glycolipids lipids attached to carbs on the cell surface Glycocalyx composed of glycolipids and glycoproteins; allows cells to recognize each other (cell-to-cell recognition) Chloesterol embedded between phospholipid molecules; gives membrane strength and rigidity Selectively permeable allows some substances