* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download The Cell Membrane - Solon City Schools
Survey
Document related concepts
Membrane potential wikipedia , lookup
Cytoplasmic streaming wikipedia , lookup
Biochemical switches in the cell cycle wikipedia , lookup
Model lipid bilayer wikipedia , lookup
Lipid bilayer wikipedia , lookup
Cell nucleus wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell encapsulation wikipedia , lookup
Extracellular matrix wikipedia , lookup
Cell culture wikipedia , lookup
Cell growth wikipedia , lookup
Signal transduction wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Cytokinesis wikipedia , lookup
Cell membrane wikipedia , lookup
Transcript
The Cell Membrane What is the cell membrane? AKA: Plasma membrane The boundary between the cell and the environment Does every cell have a cell membrane? Yes, Each and every cell has a cell membrane. Cell membranes help maintain homeostasis, what is that? 1. 2. 3. 4. Cells breathing Cells getting blood to them Cells maintaining internal conditions Cells reproducing How do cell membranes help to maintain homeostasis? The cell membrane allows nutrients to come into the cell Glucose, amino acids, lipids The cell membrane removes waste Selective Permeability The cell membrane lets some molecules in and keeps others out EX. A cell is low on glucose so the membrane lets in some glucose, but does not overfill the cell with the macromolecule. Structure of the cell membrane What does the cell membrane look like up close? Lets look at one of these structures up close Structure of cell membrane Phospholipids Phosphate head Glycerol 2 Fatty acid tails (lipids=fats, oils, etc) Phospholipids 1.) Phosphate Head Polar Hydrophilic Make up the outer borders of the membrane 2.) Fatty Acid Tails Nonpolar Hydrophobic Make up the inner part of the membrane Structure of Phospholipid Polar vs. Nonpolar Polar- positive and negative ends (b/c electrons are not shared equally) Ex. Water Nonpolar- does not have oppositely charged ends (atoms share electrons equally) Why are the phospholipids arranged tail to tail? -b/c water is inside and outside the cell phosphate group is hydrophilic (polar) end -attracts water fatty acid tail end is hydrophobic (nonpolar) -repels water Structure of cell membrane Phospholipid bilayer 2 layers of phospholipids make up a cell membrane Phospholipid Bilayer Remember polar heads and nonpolar tails Arrangement of phospholipids “tail to tail” Arrangement of phospholipids “tail to tail” due to water inside & outside the cell When something is hydrophilic, it… 1. 2. Has a chemical makeup that likes to be around water Has a chemical makeup that does not like to be around water Where would you expect to find water in this cell membrane? 1. 2. Here Here Other components of the cell membrane Cholesterol Helps to stabilize the phospholipids and keep them from sticking together Other components of the cell membrane Proteins Regulate which molecules enter and which molecules leave a cell. Types of proteins in the cell membrane Carrier Protein Allow needed substances or waste materials to move through the cell membrane Types of proteins in the cell membrane Channel or Pore protein Hydrophilic channel – allows lipid insoluble substances to pass in and out of cell. Types of proteins in the cell membrane Glycoproteins Protein with what macromolecule attached to it? Carbohydrate Functions for cell to cell recognition Types of proteins in the cell membrane Receptor Protein These have binding sites for molecules such as hormones or substrates to bind to Fluid Mosaic Model of Cell Membrane -lipid bilayer is not strong & firm like a hard shell, but it is fluid like a soap bubble (often called a fluid mosaic model) -individual phospholipids, arranged side by side, float within the bilayer (cholesterol prevents phospholipids from sticking together) Structure of Cell Membrane -nonpolar interior zone- true barrier that separates the cell from its surroundings many polar particles like sugars, proteins, ions, & most cell wastes cannot cross this zone b/c they are repelled by the nonpolar region Arrangement of cell surface proteins Cell Membrane Structure Lets build a cell membrane together http://www.wisconline.com/objects/index_tj.asp?objid=AP1101