Chapter 3 Flashcards
Functions of a cell
- cell metabolism
- Synthesis of molecules
- Communication
- Reproduction and inheritance
Outside of membrane is more ___ charged
positively
Plasma membrane made of
glycocalx (carbs and lipids and proteins on surface)
what lipids make up the membrane
phospholipids and cholesterol
Phospholipid Bilayer
Polar (hydorphilic ends) face water on interior and exterior while non polar tails inward
cholesterol of membrane
interspersed between phosphoplids
amount determine fluid nature of membrane
fluid nature of membrane allows
distribution of molecules within membrane
membranes can fuse with eachother
phoshoplipids automatically reassemble if damaged
integral protein membranes
extend deep into membrane often from one end to another
peripheral protein membranes
attach to integral protiens at inner or outer surfaces
marker molecules
glycoprotiens or glycolipids
allow cells to identify one another or other molecules
transport proteins characteristic
specificity–single type of molecules
competition–molecules of similar shape can bind
saturation–rate of transport limited to number of available carrier proteins
Leak Ion Channels
Always open
responsible for permeability of ion membrane when ion membrane is at rest
Gated Ion Channels
open or closed by certain stimuli
Ligand gated channel
open in response to small molecules that bind to proteins or glycoprotiens
Voltage gated
open when there is a change in charge across plasma membrane
Carrier proteins (ie transporters)
integral protien that moves ions from one side to another
have specific binding sites
changes shape to transport ion and then resumes original shape
