Lipids And Membranes Osmosis Flashcards
List some properties of lipids
Made up of C,H and O Macromolecules They are insoluble in water Dissolve in ethanol Good energy source Poor conductor heat and electricity
List some functions of lipids
Component of cell membranes Protection of vital organs Water proofing, to prevent evaporation To thermally insulate the body For electrical insulation, forming the myelin sheath around some neurones As a water source
Testing for lipids
- Break up small sample into a test tube with a glass rod. Add approx 2cm3 of ethanol mix well with glass rod
- Put approx 2cm3 of distilled water in a test tube
- Pour ethanol from first test tube into the body water in the second test tube and invert it to mix
Milky white emulsion forms lipid is present
Triglyceride:-
Formed by?
Molecules?
Bond?
Formed by a condensation reaction between a Glycerol and 3 fatty acids
Draw how a triglyceride is formed
Remove the H20
Called esterification
Draw fluid mosaic model
Phospholipid bilayer with embedded proteins.
Glycoproteins and glycolipids involved in cell recognition and signalling
Cholesterol
Functions of the plasma membrane
Partially permeable membrane
Selectively permeable
Cell recognition
Cell signalling
Movement of molecules across the plasma membrane list?
Simple diffusion
Facilitated diffusion
Active transport
Endocytosis and exocytosis
Define diffusion
The passive movement of molecules from an area of high concentration to an area of low concentration until an equilibrium is reached
Define osmosis
The diffusion of water from an area of higher water potential to an area of lower water potential, through a partially permeable membrane
What is a isotonic solution
What is a hypotonic solution
What is a hypertonic solution
Where there is no net movement of water
Water may enter the cell
Water may leave the cell
Percentage change equation
Change = (change/original)x100
What is facilitated diffusion?
A passive process where substances pass through a carrier protein, down a concentration gradient e.g amino acids, glucose