Chapter 9 Flashcards
osmosis
diffusiton of water through a membrane- toward high solute concentration
when does osmosis stop
when solution reaches equilibrium
What makes Na+ want to go from out to in?
The Na+ concentration gradient
Remember that the 2nd law of thermodynamics says that disorder should increase (entropy increases).
What makes Na+ want to go from out to in?
Diffusion is the random movement of molecules.Net result of diffusion is movement from a high concentration to a low.
Why do things move across membranes in a particular direction?
A concentration gradient is too ordered.
Net diffusion occurs down the gradient.
Why do things move across membranes in a particular direction?
Eventually equilibrium could be reached. Movements in both directions are then equal.
concentration gradient
Na+ ion concentrations are higher outside a cell than inside a cell.
Are ions soluble in water?
yes
Are ions soluble in lipids?
no
Could ions diffuse across a lipid bilayer?
no
Are lipids in membranes soluble in water?
no
hypotonic solution
soulutes outside< inside
hypertonic solution
solutes outside> inside
isotonic solution
solutes outside= inside
When you donate blood, your blood is collected into a bag that contains a solution of buffers and some sugar that prevents the cells from clotting and stabilizes the blood so that it can be used later.
In order for your blood to be useful, the solution in the bag should:
be isotonic relative to the blood cells
If your phlebotomist made a mistake with the solution and it turned out to be hypotonic relative to the blood cells, what would happen?
The blood cells would take-in water, swell-up and eventually lyse
proteins
made of 20 amino acids
kinds of AAs
- uncharged and hydophobic (nonpolar)
- polar uncharged and hydrophilic
- polar charged and hyrdophilic
Amino Acids are held together by?
held together by peptide bonds in proteins
four levels of protein structure
primary (unique sequence of AAs), secondary (regions of localized folding, coiled and folded) , tertiary (folding of 2nd) , quaternary (more than one coming together)
The proper shape of a protein is
determined by the sequence of its amino acids
called its conformation.
required for the protein to function.
held together by bonding interactions between the amino acid side chains.
