8.3 Flashcards
What is homeostasis and how does it work
It is a state of relatively constant internal, physical, and chemical conditions that the organisms maintain. It does this by regulating the movement of molecules and other substances from one side of the membrane to the other side.
What’s diffusion
It I’d the process by which particles move from an area of high concentration to an area of low concentration.
Give an example of diffusion
When you add sugar to coffee or tea the molecules disperse throughout the liquid until equilibrium is reached.
Give an example of diffusion across a cell membrane
In the membrane there’s a higher concentration of solute on one side compared to the other. These particles will disperse until equilibrium is reached.
Passive Transport
The movement of molecules across the cell membrane without using energy.
Facilitated diffusion
When molecules pass across the cell membrane through protein channels.
Channel proteins
Proteins in the cell membrane that act as carriers, or channels, which make it easy for certain molecules to cross the membrane.
Does facilitated diffusion require energy
No
Osmosis
Diffusion of water through selectively permeable membrane
Aquaporin
It is a channel protein that allows water to pass through it.
What can cross the membrane during osmosis
Only water
Isotonic solution
When the concentration of the two solutions are the same. Water moving equally in and out of the cell.
Hypertonic Solution
When the comparing the two solutions it is the solution with the greater concentration of solutes
Hypotonic Solution
When the comparing the two solutions it is the solution with the lesser concentration of solutes
What is active transport
The movement of materials against a concentration difference that requires energy.
Endoctysis
The process of taking material into the cell by means of infoldings, or pockets or the cell membrane
What are the two types of Endocytosis
Phagocytosis-extensions of the cytoplasm surround a particle and package it with a vacuole.
Amoebas-Method for taking in food. Engulfing material in this way requires a significant amount of energy.
Exocytosis
When many cells release large amounts of material. During this process , the membrane of the resicle or vacuole surrounding the material fuses with the cell membrane. This forces all contents out of the cell.
