Chapter 3 - Movement Into and Out of Cells Flashcards
what are particles?
the smallest pieces of which a substance is made; can be molecules, atoms and ions
what is kinetic energy?
energy of moving objects
what is diffusion?
the net movement of particles from a region of higher concentration to a reign of lower concentration (down a concentration gradient) as a result of their random movement
what is net movement?
overall or average movement
what is a concentration gradient?
an imaginary ‘slope’ from high concentration to low concentration
what is a compound?
a substance formed by the chemical combination of two or more elements in a fixed proportion
what does it mean by a partially permeable membrane?
a membrane (very thin layer) that lets some particles move through it but prevents others from passing through
what is osmosis?
the diffusion of water molecules through a partially permeable membrane
what is osmosis in terms of water potential?
the net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution) through a partially permeable membrane
what does it mean if a solution has a high water potential?
there are a lot of water molecules - dilute solution
what does it mean if a solution has a low water potential?
there aren’t many water molecules - concentrated solution
what does water potential gradient mean?
a difference in water potential between two areas
what does it mean if a plant cell is turgid?
its tight and firm
what is turgor pressure?
the pressure of the water pushing outwards on a plant cell wall
what does it mean if a plant cell is described to be flaccid?
its soft
what does it mean if a cell is described to be plasmolysed?
the cell membrane tears away from the cell wall
what is active transport?
the movement of molecules or ions through a cell membrane from a region of lower concentration to a region of higher concentration (against the concentration) using energy from respiration
what are carrier proteins (protein carriers)?
protein molecules in cell membranes that can use energy to change shape and move ions or molecules into or out of a cell
