not rigid, fluid like with the movement of molecules. “proteins drift from place to place among the phospholipids; semipermeable barrier that allows only certain things to pass through
Fluid Mosaic Model
2 layers that create the main structure of the cell membrane
The phospholipid bilayer
primary component of the cell membrane
The phospholipid bilayer
allows small molecules (water, oxygen and carbon dioxide) to pass directly into and out of the cell.
The phospholipid bilayer
The membrane is permeable to small molecules
The phospholipid bilayer
This is a protein that is embedded throughout the entire phospholipid bilayer
A transport protein
What is another name for a transport protein
A channel or Carrier protein
What helps the cell to receive chemical information
A receptor cell
Allows substances to bind to the surface of the cell
A receptor cell
These help to identify cell type
Recognition proteins
These help with adhesion, cells stick to other cell to form tissues
recognition proteins
What are glycoproteins with carbohydrate branches
recognition proteins
What are the two categories of processes
passive and active
No energy is expended by the cell in what process
passive
What must exist for passive transport?
a concentration gradient
Explain how passive transport works.
a high vs. low in amount of molecule in a given space, movement from high to low concentration, the movement continues until equilibrium is reached, a balanced bunch of molecules
What are two examples of passive transport?
diffusion and osmosis
What is diffusion?
the movement of molecules of a high to low concentration until equilibrium is reached
Name an example of diffusion in everyday life.
Oxygen and carbon dioxide
Name an example of diffusion in a cell
A Human Muscle Cell Respiring Aerobically
What is osmosis?
Diffusion of water from an area of high concentration to low, It is dependent on solute in a solution where the solvent was water
What does a red blood cell look like in an isotonic solution?
It looks normal
What does a red blood cell look like in a hypertonic solution?
It looks shriveled
What does a red blood cell look like in a hypotonic solution?
It is expanded
Diffusion of a molecule that is aided by a transport protein.
Facilitated diffusion
True or False. Movement in facilitated diffusion is always from low to high concentration.
False. It is always from high to low concentration
Explain the three steps of facilitated diffusion of a glucose molecule.
#1 After a meal, the glucose is highly concentrated in the blood and there is low concentration in the cells #2 A transport protein specific for glucose accepts a glucose molecule #3 A carrier protein helps glucose molecule move into the cell.
In active transport, a cell must expend _____ energy to move molecules across the membranes
ATP
Name 2 types of active transport
Endocytosis and exocytosis
Active transport into cell, can involve transport proteins or cell membranes engulfing molecules
Endocytosis
Name an example of endocytosis
Transport of amino acids into the cell after the digestion of a protein
This occurs when the cell membrane engulfs solid particles to carry them into cytoplasm
Phagocytosis (THINK OF YOUR BROTHER EATING HIS TWIN) HAHAHAHAHAHA
Name two examples of phagocytosis
When an amoeba feeds on bacteria
When a white blood cell engulfing bacteria and destroying them
This occurs when cells are surrounded by tissue fluids, water can move from surrounding solution into a cell, direction of water movement depends on the concentration of water molecules on wither side of the cell membrane, water concentration same in the cell water will move into and out of the cell at the same rate, surrounding solution is isotonic, molecules highly concentration inside cell water will move out of the cell, surrounding solution is hypertonic molecules are more highly concentrated in surrounding solution water will move in the cell, the cell gets bigger (cytosis)
Pinocytosis
Explain exocytosis
#1 Food particle taken in by endocytosis #2 Fusion forms a secondary lysome #3 Food particles are digested #4 Waste is removed via exocytosis