Transport/Membranes Flashcards
What makes up a Cell Membrane?
Phospholipid Bilayer Intrinsic Proteins Extrinsic Proteins Cholesterol Glycolipids
What is the Role of Cholesterol in the Cell Membrane?
Provide Stability
What makes up Phospholipids?
2 Fatty Acids
Glycerol
Phosphate Group
-Hydrophobic tail and Hydrophilic head
What can pass through Phospholipid Bilayer?
Lipid soluble molecules
Water and other small substances
-Diffuse through
What cannot pass through Phospholipid Bilayer?
Water soluble (polar) and larger molecules
What is the Fluid-mosaic Model?
Fluid-Molecules are moving
Mosaic-Proteins and Phospholipids fit together
What is Diffusion?
Net movement of particles from area of High to Low Concentration
Passive Process- Down Conc Gradient
What Increases rate of Diffusion?
Bigger SA
Shorter Diffusion Path
Higher Temp
Bigger Conc Gradient
Why might Carrier Proteins become a Limiting Factor in Facilitated Diffusion?
May become Fully Saturated with molecules-can’t carry any more across membrane
What is Facilitated Diffusion?
Where molecule is too large/polar-cannot diffuse through Bilayer
Diffuses via Carrier Proteins- Specific to the Substance
Similar to diffusion-down conc gradient so passive
What is Osmosis?
Net movement of Water from area of High to Low Concentration, across Partially Permeable Membrane
Passive Process- Down Conc Gradient
What will happen to animal cells in a Hypotonic Solution?
They may burst
What will happen to animal cells ion an Isotonic Solution?
They will stay the same
What will happen to animal cells in a Hypertonic Solution?
They may shrink
What are the steps of Active Transport?
Ion binds to Carrier Protein on Receptor Sites
On inside of Membrane, ATP binds to Protein
ATP Hydrolysed to form ADP and Pi
Protein Changes Shape and Opens to other side
Ion Released
Pi released from Protein
Protein changes back to Original Shape
