Science Lessons 8.3-8.4 Flashcards
how does osmosis work
水 goes through cell membrane to make inside and outside equal.
水 moves through selectively permeable barrier from lower to higher concentration.
In the cell, 水去 osmosis through aquaporins in cell membrane.
Water can cross barrier in both directions, but sugar can’t.
（Sugar molecules wont go from one side to other）
Water move across membrane from area of low concentration to high until equilibrium reached.
Equilibrium 是 reached, both sides will have the same amount of solute and be considered isotonic.
what are hypertonic and hypotonic solutions
Hypertonic solutions have a more concentrated solution, or “above strength”
Hypotonic solutions have a more diluted solution, or “below strength”
What is facilitated diffusion
Facilitated diffusion 是 when molecules pass through special protein channels because 他们 can’t diffuse across the cell membrane directly.
What are the types of passive transport
passive agressive
F(ork)acilitated diffusion
O(ff)smosis
D(illhead) iffusion
What are the types of active transport
M(may)olecular transport
B(be)ulk transport
endocytosis
exocytosis
What is diffusion and how does it work
Diffusion is when particles move from an area of high concentration to an area of low concentration. It is the driving force behind the movement of substances across a cell membrane.
What is exocytosis and endocytosis and how do they work
Exocytosis is when the membrane of the vesicle or vacuole surrounds a material and forces it to fuse, or join with, the cell membrane. This forces contents out of the cell, like water.
Endocytosis is the process of taking material into the cell by folding it into the cell membrane. It forms a pocket around the a particle and engulfs it.
What is the role of aquaporins during osmosis and diffusion
protiens- to assist the particles so they dont have t go though the membrane
What do bacteria and amoebas have in common
They both reproduce individually.
What is a receptor
receptor accepts and responds to molecular signals.
Cells must have receptor to which signal molecule can bind.
What defines a tissue in your body
group of similar cells that perform same function
How do cells maintain homeostasis
Homeostasis 是 state of constant internal physical and chemical conditions.
一个 cell can maintain homeostasis by controlling movement of molecules and other substances from one side of the membrane to other
how does diffusion work
Diffusion causes a net movement of solute particles from the side of the membrane with the higher solute concentration to the side with the lower solute concentration. Once equilibrium is reached, solute particles continue to diffuse across the membrane in both directions at equal rates, so there is no change in solute concentration.
