A Cell Mitochondrion Nucleus Selectively permeable cell membrane Cytoplasm.
Cell Membrane. Function 1.Separates cytoplasm from external environment 2.Regulates what enters and...
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Transcript of Cell Membrane. Function 1.Separates cytoplasm from external environment 2.Regulates what enters and...
Cell Membrane
Function
1. Separates cytoplasm from external environment
2. Regulates what enters and leaves cell
3. Cell identification
4. Cell-cell communication
Plasma membrane regulates movement of
materials due to its chemical
composition:Phospholipids
CholesterolProteins
Phospholipids
• Phospholipids BilayerPhospholipids have:1. Hydrophilic head
2.Nonpolar hydrophobic tail
Hydrophilic "heads" faces the watery environment inside and outside cell
Hydrophobic tail forced to face inward – away from water.
The phospholipids are
not bound together –
gives the membrane a
fluid nature
CHOLESTEROL
• Function:
1.Stabilizes membrane (structural support)
2.Cell communication (cell-cell and cell-hormone)
Some interesting facts
• Most common molecule in membrane (>50%)
• Due small size and weight – only 20% of membrane mass
• Is an amphipathic molecule Homework – find out what this means
Proteins
• Are embedded in membrane
• Serve different functions
Functions
• 1. Channel Proteins - small openings for molecules to diffuse through
• 2. Carrier Proteins- binding site on protein "grabs” molecules, pulls them into cell
• 3. Receptor Proteins – act as triggers that set off cell responses (such as release of hormones or opening of channel proteins)
• 4. Cell Recognition Proteins - ID tags, identify cell to immune system
• 5. Enzymatic Proteins - carry out metabolic reactions
LABEL YOUR DIAGRAM WITH THE FOLLOWING
DETAILS
Task: Due end of class
• Read pages 47 -49 in your text
• Answer questions 1 – 5 in practice section
• Explain the structure and function of glycoproteins.
• How are liposomes used in cancer treatment and gene therapy?
• What role might receptor proteins have in medical disorders such as Hypertension?