null
US
Sign In
Sign Up for Free
Sign Up
We have detected that Javascript is not enabled in your browser. The dynamic nature of our site means that Javascript must be enabled to function properly. Please read our
terms and conditions
for more information.
Next up
Copy and Edit
You need to log in to complete this action!
Register for Free
3379833
Internal Organization of the cell
Description
Mind Map on Internal Organization of the cell, created by Cesar Corona Flores on 06/09/2015.
Mind Map by
Cesar Corona Flores
, updated more than 1 year ago
More
Less
Created by
Cesar Corona Flores
almost 9 years ago
Copied by
LCM
almost 9 years ago
Copied by
Cesar Corona Flores
almost 9 years ago
3
0
0
Resource summary
Internal Organization of the cell
Membrane Structure
Plasma membrane
Encloses cell, defines its boundaries and maintains the essencial differences between cytosol and extracellular environment
Eucaryotic cells, membranes, endoplasmic reticulum, golgi apparatus, mitochondria, membrane-enclosed
4 phospholipids
phosphatidylcholine
phosphatidylethanolamine
phosphatidylserine
Translocation in apoptotic cell by two mechanism
The phospholipid translocator is inactivated
Scramblase that transfer phospholipids in both directions is activared
sphingomyelin
Ion gradients
Across membrane, activities of membrane proteins, synthesize ATP, movement of selected solute,produce electrical signals
thin film of lipid and protein molecules held by noncovalent interactions
Lipid Bilayer
Fluid structure, impermeable barrier to water-solube molecules
Lipid Molecules
Amphipathics that have hydrophilic end and a hydrophobic end
Phospholipids
Have a polar head group and two hydrophobic hydrocarbon tails
phospholipases
activated by extracellular signals to cleave phospholipid
depends on composition and temperature
Cholesterol
enhance the permeability-barrier
glycolipids
Liposomes
spherical vesicles
Black Membrane
Planar billayers
Phospholipid translocators
Membrane-bound enzymes, catalyze the rapid flip-flop of phospholipids
PARTE DE MATIAS
Membrane properties
Glycolipids In the surface of the membrane
The glycolipids are lipid molecules with the most extreme asymmetry
These molecules are found in the noncytosolic monolayer of the lipid bilayer
The glycolipids tend to self-associate,
Through hydrogen bonds between their sugars
Are in the cell surface where they have important roles
Some glycolipids provide entry points for certain bacterial toxins
Membrane proteins
Membrane proteins perform most of the specific functions of membranes
Most trans-membrane proteins are thought to extend across the bilayer as a single a helix,
Many proteins are attached to the membrane only by noncovalent interactions with other membrane proteins
Membrane Proteins Can Be Associated with the Lipid Bilayer in Various Ways
Many extend through the lipid bilayer of the membrane, with part of their mass on either side
These transmembrane proteins are amphipathic
Having regions that are hydrophobic and regions that are hydrophilic
Their hydrophilic regions are exposed to water on either side of the membrane.
Their hydrophobic regions pass through the membrane and interact with the hydrophobic
Only transmembrane proteins can function on both sides of the bilayer or transport molecules across it.
Proteins bound to the plasma membrane can be readily distinguished by the use of an enzyme called phosphatidylinositolspecific
Many of the proteins of this type can be released from the membrane by relatively gentle extraction procedures
Such as exposure to solutions of very high or low ionic strength
Of extreme pH, which interfere with protein– protein interactions but leave the lipid bilayer intact
In Most Transmembrane Proteins the Polypeptide Chain Crosses the Lipid Bilayer in an a-Helical Conformation
A transmembrane protein always has a unique orientation in the membrane.
The hydrogen bonding between peptide bonds is maximized if the polypeptide chain forms a regular a helix as it crosses the bilayer
In single-pass transmembrane proteins, the polypeptide crosses only once
Whereas in multipass transmembrane proteins, the polypeptide chain crosses multiple times
Because transmembrane proteins are notoriously difficult to crystallize, relatively few have been studied in their entirety by x-ray crystallography.
Some b Barrels Form Large Transmembrane Channels
Multipass transmembrane proteins are comparatively rigid and tend to crystallize readily.
The number of b strands varies widely, from as few as 8 strands to as many as 22
The b barrel proteins are abundant
in the outer membrane of mitochondria, chloroplasts
Many Membrane Proteins Are Glycosylated
The great majority of transmembrane proteins in animal cells are glycosylated.
Membrane Proteins Can Be Solubilized and Purified in Detergents
The transmembrane proteins can be solubilized only by agents
That disrupt hydrophobic associations and destroy the lipid bilayer.
As in glycolipids, the sugar residues are added in the lumen of the ER and Golgi apparatus
In many bacterias
Show full summary
Hide full summary
Want to create your own
Mind Maps
for
free
with GoConqr?
Learn more
.
Similar
PHYSICS P1 1
x_clairey_x
Year 11 Psychology - Intro to Psychology and Research Methods
stephanie-vee
IB SL Biology: Cell Division
mcgowan-w-10
CPA Exam Sample Questions Pt. 1
nedtuohy
Advantages and Disadvantages of Parliamentary Law making
Sinead Gapp
Nervous System
4everlakena
The Rise of the Nazis
shann.w
The League of Nations and the Manchurian and Abyssinian Crises Quiz
Leah Firmstone
Maths: Geometry
noajaho1
2PR101 1.test - 8. část
Nikola Truong
Diseño de Software
Verny Fernandez
Browse Library