Passive Transport
What is the main difference between passive and active transport?
passive transport does not require energy, while active transport does
Define active transport
Movement of molecules across a cell membrane against their gradient concentration
This molecule makes up most of the cell membrane and has a hydrophilic head and hydrophobic tail.
Phospholipid
What is the function of phospholipids?
They form the structure and maintain the functions of the cell membrane.
This process allows water to move across a selectively permeable membrane from an area of high water concentration to a low water concentration.
osmosis
What energy is used in active transport to move molecules across the cell membrane?
ATP
These lipids help maintain the fluidity and rigidity of the cell membrane.
Cholesterol
What is the function of channel proteins?
To act as gateways to permit the transport of specific substances across the membrane.
In passive transport, what determines the rate at which molecules diffuse across the membrane, and how do temperature and molecule size affect this rate?
the concentration gradient, temperature, and molecule size. High temp increases diffusion rate, and smaller molecules diffuse faster.
What role do protein pumps play in active transport?
They move substances across the cell membrane against their gradient concentration
These carbohydrate chains attach to proteins on the cell membrane and play a role in cell recognition
Glycoproteins
What is the function of oligosaccharides?
To act as “street addresses” that identify individual cells.
What is the role of the cell membrane in passive transport?
controls what enters and leaves the cell while allowing passive transport to happen
How does bulk transport differ from other forms of active transport?
Bulk transport deals with larger molecules
These proteins are embedded within the lipid bilayer and can sometimes span the entire membrane, helping with transport.
Integral Protein
What is the function of pumps in transport?
These transmembrane proteins actively move ions across the membrane against a concentration gradient.
Glucose cannot easily pass through the lipid bilayer, so it enters the cell using this specific type of transport protein in facilitated diffusion
carrier protein
What does the sodium-potassium pump do
Maintains concentration differences
This model displays the structure of the cell membrane as a dynamic and flexible combination of lipids, proteins, and carbohydrates
Fluid Mosaic Model
What are the functions of glycolipids?
This type of lipid molecule helps to maintain membrane stability and to facilitate cellular recognition and cell-to-cell communication