Cell Transport Flashcards
Define diffusion.
The net movement of molecules into regions of low concentration.
Define osmosis.
The net movement of water molecules into regions with high concentrations of solute.
What is an isotonic environment?
When the solute concentration is the same on the outside and inside of the cell.
What kind of cells can survive in an isotonic environment?
Animal cells are normally in an isotonic environment, but plant cells can’t survive because they need to draw in water and nutrients.
What is a hypotonic environment?
When the solute concentration is lower on the outside of the cell than on the inside.
What kind of cells can survive in hypotonic environments?
Plant cells like hypotonic environments, as well as cells with contractile vacuoles such as freshwater protists, unlike animal cells which will lyse/explode.
What is a hypertonic environment?
When the solute concentration is higher on the outside of the cell than on the inside.
What kind of cells can survive in hypertonic environments?
Most cells cannot survive; animal cells shrivel and plant cells pull away from cell walls.
Which molecules can diffuse across the phospholipid bilayer?
Small, non-polar molecules like gasses, steroids and hormones.
How do amino acids, monosaccharides, ions, and other small polar molecules cross the phospholipid bilayer?
Membrane transport proteins.
What kind of molecules are moved across the cell membrane via exo or endocytosis?
Large molecules such as proteins.
Where are Na+ pumps found?
Animals.
Is Na+ pumped into or out of animal cells?
Out of animal cells.
Where are H+ pumps found?
In plants, fungi, protists, prokaryotes.
Is H+ pumped into or out of cells?
Out of cells.
What do H+ powered transporters transport?
They actively transport ions and monomers.
What do Na+ powered transporters transport?
They actively transport ions and monomers.
What is the difference between phagocytosis and receptor mediated endocytosis?
Phagocytosis is when a cell extends outward to engulf a single large object; receptor mediated endocytosis is when target molecules (ligands) bind to membrane proteins (receptors) and are brought within a vescicle.
