Chapter 7 (2) - Chapter 7 Membrane Structure and Function...

Info iconThis preview shows pages 1–14. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 7 Membrane Structure and Function
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Concept 7.1: Cellular membranes are fluid  mosaics of lipids and proteins Phospholipids Most abundant lipid in plasma membrane Amphipathic :  hydrophobic & hydrophilic regions
Background image of page 2
Fluid mosaic model  of membrane  structure Membrane is a fluid structure with a  “mosaic” of various proteins embedded in it
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Davson-Danielli sandwich model (1960’s) Stated that membrane was made up of  phospholipid bilayer sandwiched between two  protein layers
Background image of page 4
Proposed that membrane proteins are  phospholipid bilayer Figure 7.3 Phospholipid bilayer Hydrophobic region of protein Hydrophobic region of protein
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Fluidity of Membranes Phospholipids in plasma membrane Can move within bilayer Figure 7.5 A Lateral movement (~10 7 times per second) Flip-flop (~ once per month) (a) Movement of phospholipids
Background image of page 6
Proteins in plasma membrane Can drift within bilayer EXPERIMENT Researchers labeled the plasma mambrane proteins of a mouse cell and a human cell with two different markers and fused the cells. Using a microscope, they observed the markers on the hybrid cell. Membrane proteins Mouse cell Human cell Hybrid cell Mixed proteins after 1 hour RESULTS CONCLUSION The mixing of the mouse and human membrane proteins indicates that at least some membrane proteins move sideways within the plane of the plasma membrane. Figure 7.6 +
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Type of hydrocarbon tails in phospholipids Affects fluidity of plasma membrane Figure 7.5 B Fluid Viscous Unsaturated hydrocarbon tails with kinks Saturated hydro- Carbon tails (b) Membrane fluidity
Background image of page 8
Cholesterol Different effects at different temps (low temps    high cholesterol, hibernating animals, moderate  temps   less fluidity ) Figure 7.5 (c) Cholesterol within the animal cell membrane Cholesterol
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Figure 7.7 Glycoprotein Carbohydrate Microfilaments of cytoskeleton Cholesterol Peripheral protein Integral protein CYTOPLASMIC SIDE OF MEMBRANE EXTRACELLULAR SIDE OF MEMBRANE Glycolipid Membrane Proteins and Their Functions Collage of different proteins embedded in  fluid matrix of lipid bilayer Fibers of extracellular matrix (ECM)
Background image of page 10
Integral proteins Penetrate hydrophobic core of lipid bilayer Often transmembrane  proteins, completely  spanning the membrane EXTRACELLULAR SIDE Figure 7.8 N-terminus C-terminus α Helix CYTOPLASMIC SIDE
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Peripheral proteins Appendages loosely bound to surface of  membrane
Background image of page 12
6 major functions of membrane proteins Figure 7.9 Transport. (left) A protein that spans membrane may provide a hydrophilic channel across the membrane that is selective for a particular solute. (right)
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 14
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 48

Chapter 7 (2) - Chapter 7 Membrane Structure and Function...

This preview shows document pages 1 - 14. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online