9.2 Diffusion and Osmosis Flashcards
What is simple diffusion?
The passive movement of particles from an area of higher concentration to an area of lower concentration
Simple diffusion does not require energy or transport proteins.
What is facilitated diffusion?
The process of transporting molecules across a cell membrane via protein channels due to concentration gradients
Facilitated diffusion is passive and does not require energy.
Define osmosis.
The diffusion of water across a selectively permeable membrane
Osmosis occurs from an area of lower solute concentration to an area of higher solute concentration.
What does hypertonic mean?
A solution that has a higher concentration of solutes compared to another solution
In a hypertonic solution, cells may lose water and shrink.
What does hypotonic mean?
A solution that has a lower concentration of solutes compared to another solution
In a hypotonic solution, cells may gain water and swell.
What does isotonic mean?
A solution that has the same concentration of solutes as another solution
In an isotonic solution, there is no net movement of water into or out of the cell.
What is active transport?
The movement of particles against a concentration gradient, requiring energy
Active transport utilizes ATP to move substances.
Define endocytosis.
The process by which cells engulf external substances, bringing them into the cell
Endocytosis can occur via phagocytosis or pinocytosis.
Define exocytosis.
The process by which cells expel materials from the cell via vesicles
Exocytosis is vital for secretion of substances like hormones.
What are the properties and structure of phospholipids?
Phospholipids consist of a hydrophilic head and two hydrophobic tails
They form the bilayer of cell membranes, allowing selective permeability.
Identify parts of the cell membrane.
Includes phospholipids, cholesterol, proteins, and carbohydrates
Each component plays a role in membrane fluidity, transport, and signaling.
What is the importance of surface area to volume ratio?
A higher surface area to volume ratio allows for more efficient exchange of materials
Cells need to maximize their surface area to support metabolic processes.
Compare and contrast different types of transport.
Transport types include:
* Passive Transport: moves down concentration gradient, no energy, includes diffusion and facilitated diffusion
* Active Transport: moves against concentration gradient, requires energy
* Bulk Transport: includes endocytosis and exocytosis
Passive transport does not require transport proteins, while active transport does.
How can you predict which way solutes will diffuse across a membrane?
Solutes will diffuse from an area of higher concentration to an area of lower concentration
The direction of diffusion is influenced by the concentration gradient.
How can you predict which way water will diffuse across a membrane via osmosis?
Water will diffuse from an area of lower solute concentration to an area of higher solute concentration
This movement continues until equilibrium is reached.
