Movement of solutes across a lipid bilayer plasma membrane can occur in many ways:
1. Osmosis: diffusion of water across membranes to balance solute concentrations.
- No energy req
- Water passes through membrane via aquaporins, pores in the membrane permeable only to water.
2. Simple diffusion: diffusion of only small, hydrophobic (nonpolar) molecules across a membrane down their concentration gradient.
- No energy req
- Only moves small nonpolar molecules down their concentration gradient
3. Facilitated diffusion (passive transport): uses transmembrane protein transporters (channels and carriers) to move polar molecules (ions) across a membrane
- No energy required
- Channel proteins: Allow for rapid diffusion of specific ions down their concentration gradient
- Can be activated by:
- Voltage
- Ligand
- Mechanical force
- Carrier proteins: Allow for selective diffusion of specific ions down their concentration gradient.
- Uniport carriers: only transport one specific ion down its concentration gradient
- Symport carriers: move two different types of ions in the same direction.
- Antiport carriers: moves two different ions in opposite directions
-Can use the energy created moving one molecule down its concentration gradient to move an ion against its concentration gradient
- Carrier proteins exhibit saturation, competition, and specificity.
4. Active transport: transport of solutes across a membrane against their concentration gradient.
- ATP req
- Uses carrier proteins
- Leads to creation of potential energy stored in electrochemical gradients
Liquids and gases are amorphous (shapeless), viscous (can flow), and diffuse (have internal space) due to the movement of their molecules.
Molecules made of carbon and hydrogen are various and diffuse. The best description is that they are hydrocarbons and they burn well.
The random motion of the gas molecules allows them to diffuse throughout the space available to them.
my mom
The rate of diffusion of a gas depends on the weight of the gas molecules. The heavier the molecules, the slower they move - the lighter the molecules, the faster they move. Nitrogen molecules weigh about 28 units. Chlorine molecules weigh 71 units. So we would expect nitrogen to diffuse more quickly than chlorine.
All types of molecules
Oxygen molecules diffuse across the membrane.
Water molecules freely diffuse across a semipermeable membrane.
No.
no because different molecules have different sizes. Smaller molecules will diffuse faster than larger molecules.
The concentration gradient is what causes molecules to diffuse.
the reach equilibrium
The molecules of food and oxygen diffuse into cells. oh and btfw co2 and waste chemicals diffuse ut of cells. im in year 3
The Kidneys
Carbon dioxide, oxygen and some nonpolar molecules diffuse easily.
No, smaller molecules generally diffuse more readily than larger molecules because they can move through pores and gaps in substances more easily due to their smaller size. This is why smaller molecules like oxygen and carbon dioxide can diffuse through cell membranes more quickly than larger molecules like proteins.
veins