Maintaining Homeostasis: Control of the Cell's Internal Environment Flashcards
Phospholipid Head region
polar (slightly charged), hydrophilic “water-loving”
Tail region
non-polar (no charge), hydrophobic “water-fearing”
cholesterol molecule
helps maintain the fluid conditions of the bilater
integral protein
channel for ions + larger molecules to get into and out of the cell
peripheral protein
connected to cytoskeleton filament
alphahetic protein
channel for nutrients entering the cytoplasm
gycoprotein
protein with attatched carbohydrates
carbohydrate
involved in cell recognition as receptors for things like hormones + insulin
In order for the ___to survive. it needs to ___what goes in and out of it.
cell
control
Cell membrane is set up to do?
hydrophilic
hydrophobic
What will hydrophilic heads do?
repel uncharged molecules, like CO2
What will hydrophobic tails do?
repel charged molecules, like NA2+
Will small particles pass through the cell membrane freely?
yes
The cell needs to allow certain things inside (food, water, hormones, ions, etc) and things to leave (wastes, poisons, etc.). It does this either___(__ __ __), or ___(__ __)?
passively (without using energy)
actively (requires energy
What is passive transport?
The movement of molecules across the cel lmembrane without the expenditure of chemical energy (ATP).
Why does passive transport take place?
Some molecules are able to apss through tiny gaps in the cell membrane.
What are the four types of passive transport?
diffusion
osmosis
facilitated diffusion
ion channels
What is the concentration gradient?
all particles will naturally move from an area of high concentration to an area of low concentration.
What is diffusion?
The movement of small molecules (oxygen, carbon dioxide) from an area of high concentration to an area of low concentration.
What is concentration?
The number of molecules divided by the volume.
Diffusion occurs in___and___via random movement (collisions, bouncing).
liquids and gases
Diffusion requires only the energy provided by what? Why?
heat since a large amount of motion cannot occur in frozen cells.
What does increasing temperature cause the molecules to do in diffusion?
causes the molecules to move more rapidly therefore they collide more often and diffuse more rapidly
Diffusion will occur until there is no what? At this point, we say that___has been reached?
no net movement from one area to another
equilibrium
What is osmosis?
The natural movement of water across a selectively permeable membrane from an area of high water concentration to an area of low water concentration.
What is the opposite of osmosis?
diffusion