Composition + structure of Membrane

Composition + structure of Membrane

1. Eukaryotic cell

   • Nucleus
     • Genetic information that encodes RNA and protein

2. Prokaryotes

   • No true nucleus
     • Genetic information flow around cytosol

3. Microbiome

   • the population fo microbiotic organisms in human
     • Body makes of 10 times more microbiotic organism
       • Essential for physiological function
         • May be harmful but controlled by immune system
       • Make up of 2-3% of body weight
     • Streptococcus Salivarius
       • inhibits upper respiratory tract and oral cavity
       • Makes up the bacteria that forms dental plaque
       • First microbiotic organisms to inhibit the oral cavity and gastrointestinal tract of new borns
     • Staphylococcus Haemolyticus
       • Resides on skin
       • pathogenic when inside the body
     • Bacteriode Thetaiotamicron
       • produce enzymes that break down palnt materials
       • Inhibits intestinal tract

4. Human develop as single cell

   • Egg + sperm to form fertilized egg, embryo
     • Mitotic division
       • Divide into multiple cells that comes from same gene heritage but different functions

5. cell membrane

   • made up of phospholipid bilayer
     • Fluidity
       • viscosity of bilayer
         • Phospholipids move laterally
           • Does not flip from one side to another without use of energy
       • Factors Influecing
         • 1. Temperature
           • Increase in Temp, In crease in fluidity, constant shaking
             • Decrease in Temp, decrease in fluidity, less shaking of phospholipids
           • More adapted to cold weather have more saturated phospholipid to maintain fluidity
         • 2. Type of Hydrocarbon
           • Unsaturated bonds, increase in fluidty
             • kinked tails, that pushes phospholipids apart
           • Saturated bond, decrease in fluidty
             • Straight tails that cause phospholipids to be more packed together
         • 3. Prescence of Cholesterol
           • Normal temperature, decreases fluidity because fills the space btw phospholipids
           • Cold weather, increases in fluidty, because keeps phospholipids apart
           • Steroids packs closely to neighbouring phospholipids
         • 4. # of Hydrocarbons in tail
           • Increase in length of tail, increase in van der wall interactions, dcreases fluidity
     • subsequently aggregates without energy
       • forms lipid micelles
         • absorb fat soluble vitamins and complex lipids
   • Semipermeable
     • allows entrance of important components and dispose of wastes
     • Protect against toxins
     • fluid mosaic models
       • made up of protein, lipids and carbs
         • carbs and protein attaches to lipid or proteins
   • steroids
     • Amphipathic
       • hydrophilic head: glycerol + phosphate grou
         • Interacts with aqueous surroundings
       • hydrophobic Tail: 16-18 carbons
         • form core of membrane, and interacts by Van der Waal forces
     • makes up about 50% of lipid bilayer
     • 4 hydrocarbon ring structure
   • Lipid Draft
     • low fluidity region in membrane
       • long and saturated hydrocarbon tails which increased interaction
         • Closely Packed together
       • Hold macromolecule
         • Gathering of proteins for syntehsis
           • collection of receptors on surfaces

6. Cell

   • membrane bounded molecules containing macromolecules
   • Nucleic Acid
     • Hereditary information of cell in DNA, chromose, nucleoids
     • encoded to produce functional produces such as RNA and protein
   • Carbohydrates
     • energy storage
       • structural component of cell( cell wall)
   • Proteins
     • Majore structrual component of cell
       • flagellum
     • transport products acroos membrane
     • perform metabolic processes
   • Phospholipids
     • important component of cell membrane

7. Transporting Molecuels Across Membrane

   • Diffusion
     • Requires NO ENERGY
     • From low to high concentration
     • Small hypertonic molecules, non polar molecuels and 1% H20
     • Molecule come driectly in contact with lipid layer and cross lipid porins
   • Active Transport
     • Moving against Concentratio gradient
     • Primary Active Transport
       • Energy cause a transformational change of membrane protein
         • pumps out substances
     • requries energy from hydrolosis of ATP
     • Secondary Transport
       • Sodium Potassium Pump
         • 1. Every 3 sodium pumped out, 2 potassium are pumped in
           • 2. Atp gives up a phosphate group to transport protein, causing conformation change in shape of protein
             • 3.binds 2 K ions into the cell, phosphate group is released, return original shape and release potassium into cytoplasm
       • transmembrane protein uses the electro chemical gradient created by primary transport to move own against graident
   • Facilitated Transport
     • NO ENERGY
     • move with gradient
     • Help of Transmembrane Proteins
     • Channel
       • Open
     • Carrier
       • Molecules, bind and change shape
     • ions and hydrophilic molecules
   • no energy
     • Osmosis
       • water can be transported faster with aquaporin transmembrane proteins
         • diffuse from more concentrated to low concentrated
       • isotonic
         • Equal concentration in and out of cell
           • No net movement
       • Hypertonic
         • water moves out of cell due to low concentration of solute in cell
           • Cell shrinks
       • Hypotonic
         • water moves into the cell , due to high concentration of solute in cytosol
           • cell bursts

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