STM 007 Module 14: Plasma Membrane Components PDF

MODULE 14: THE STRUCTURE AND COMPONENTS OF PLASMA MEMBRANE Learning Objectives: 1. Identify the different components of the plasma membrane 2. Describe the characteristics and function of the different components of the plasma membrane PLASMA MEMBRANE - a semi-per...

MODULE 14: THE STRUCTURE AND COMPONENTS OF PLASMA MEMBRANE Learning Objectives: 1. Identify the different components of the plasma membrane 2. Describe the characteristics and function of the different components of the plasma membrane PLASMA MEMBRANE - a semi-permeable membrane that regulate what goes in and out of the cell * base of attachment for the cytoskeleton or the cell in some organisms * supports and maintains shape of the cell * regulates cell growth through balance of ENDOCYTOSIS and EXOCYTOSIS ENDOCYTOSIS - substances are brought INTO the cell EXOCYTOSIS - substances are brought OUT of the cell STRUCTURAL COMPONENTS OF PLASMA MEMBRANE A. CELL MEMBRANE LIPIDS B. CELL MEMBRANE PROTEINS 1. PHOSPHOLIPIDS - lipid bilayer and semi-permeable 1. INTEGRAL MEMBRANE PROTEINS and PERIPHERAL MEMBRANE PROTEINS 2. CHOLESTEROL - selectively dispersed in between phospholipids - INTEGRAL PROTEINS cross all the way through the lipid - keeps plasma membrane from becoming too stiff; avoids the bilayer whereas PERIPHERAL PROTEINS are located on only phospholipids from being packed too closely together one side of the bilayer (either inside or outside) 3. GLYCOLIPIDS - hydrophilic heads (lipid molecules) with carbohydrate sugar chain attached to them - INTEGRAL PROTEINS transmit signals or transport - for the cell to recognize other cells of the body (like an ID) molecules from one side of the membrane to the other side while PERIPHERAL PROTEINS are also involved in signal transmissions but only on one side of the bilayer 2. STRUCTURAL PROTEINS - provides support and shape to the cell 3. RECEPTOR PROTEINS - communication link of the cell to the external environment through the use hormones or neurotransmitters 4. TRANSPORT PROTEINS - transport molecules across cell membranes through facilitated diffusion 5. GLYCOPROTEINS - protein molecules with carbohydrate chain attached to them - assist in cell to cell communication