Chap_5 - Chapter 5 Cell Membrane Structure and Function The...

Info iconThis preview shows pages 1–21. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 5 Cell 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
The cell membrane is usually the outermost barrier of the cell. An exception to this is found in cells which have a cell wall plants - cellulose fungi - chitin bacteria - chitin plus proteins
Background image of page 2
The cell wall is mainly for structural support and protection. It usually doesn’t act as a barrier to molecules.
Background image of page 3

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

View Full DocumentRight Arrow Icon
The Plasma Membrane The plasma membrane contains the cell but still allows the cell to interact with the environment.
Background image of page 4
Fig. 4.2
Background image of page 5

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

View Full DocumentRight Arrow Icon
The plasma membrane functions: 1. Isolate the cell environment 2. Regulate exchange between inside and outside 3. Communicate with other cells 4. Identify the cell type
Background image of page 6
Cell Identification Membrane proteins provide a ‘fingerprint’ for the cell type. HIV binds to cell receptors that are present on cells inside the body, but not present on skin cells. Called CD receptors (cluster of differentiation). This is why it is unlikely that you will contract HIV through casual contact.
Background image of page 7

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

View Full DocumentRight Arrow Icon
---Plasma membrane is the membrane at the boundary of every cell that acts as a selective barrier, thereby regulating the cell’s chemical environment. 1. Membranes are made primarily of lipid 2. Phospholipids are molecules which can form membranes naturally
Background image of page 8
Fig. 5.3
Background image of page 9

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

View Full DocumentRight Arrow Icon
Cell membranes are phospholipid bilayers 0 Evidence: The phospholipid content of red blood cells is just enough to cover the cell with two layers. The red blood cell has no internal membranes.
Background image of page 10
Biological membranes contain proteins Evidence: Membranes isolated from red blood cells contain proteins in addition to lipids.
Background image of page 11

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

View Full DocumentRight Arrow Icon
Singer and Nicholson: Fluid Mosaic Model Fig. 5.1
Background image of page 12
---Fluidity in membranes means there is lateral two-dimensional movement of the lipids and some proteins in the plane of the membrane. However, transverse (flip-flop) across the membrane is rare.
Background image of page 13

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

View Full DocumentRight Arrow Icon
Background image of page 14
--- Mosaic aspect of membranes means that there are proteins interspersed within the lipid bilayer.
Background image of page 15

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

View Full DocumentRight Arrow Icon
Some functions of membrane proteins 1. transport proteins channel proteins - pores carrier proteins - selective revolving doors 2. receptors 3. cell-to-cell recognition
Background image of page 16
glycoprotein extracellular fluid (outside) cholesterol phospholipid bilayer phospholipid recognition protein receptor protein transport protein carbohydrate binding site Fig. 4.1
Background image of page 17

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

View Full DocumentRight Arrow Icon
Some of the recognition keys on the surface of cells are glycoproteins ---Glycoproteins are proteins which have a carbohydrate attached to them.
Background image of page 18
glycoprotein extracellular fluid (outside) cytoplasm (inside) cholesterol phospholipid bilayer phospholipid recognition protein receptor protein transport protein protein filaments carbohydrate binding site Fig. 4-1
Background image of page 19

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

View Full DocumentRight Arrow Icon
TRANSPORT ACROSS MEMBRANES Transport is movement. Movement of molecules requires two factors
Background image of page 20
Image of page 21
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 71

Chap_5 - Chapter 5 Cell Membrane Structure and Function The...

This preview shows document pages 1 - 21. Sign up to view the full document.

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