Lipids, membrane and transport Flashcards
What does saturated mean?
single bonds
What does unsaturated mean?
double bonds
What reaction joins glycerol together into a triglycerides?
Condensation reactions
What bond is formed between glyercol
Ester bond
What are the features of a phospholipid?
Polar/hydrophilic head
non-polar/hydrophobic tail
What is the test for lipids?
add ethanol to sample shake thoroughly to dissolve any lipid then add water the shake gently milky white colour suggests lipid
What do plasma membranes do?
control transport of substances
act as a receptor site
separates cell from environment
What does a phospholipid bilayer do?
acts as a barrier to polar/water soluble/large molecules
allows non polar/insoluble/small molecules through
What is simple diffusion?
moves down a concentration gradient
reaches dynamic equilibrium
What is facilitated diffusion?
channel protein allows molecules through
specify - calcium channels will transfer calcium down the concentration gradient
What does hypertonic mean?
lower water potential
What does hypotonic mean?
higher water potential
What does isotonic mean?
same water potential as cell
Why is active transport different to osmosis?
it goes against the concentration gradient instead of down it
it requires ATP whereas osmosis does not
