Membrane Passive transport Flashcards
What is Passive Transport?
Passive Transport is the movement of the cell across a membrane without using energy
Give me two examples of passive Transport.
Diffusion and Osmosis
During passive transport , do particles move UP or DOWN the concentration gradient?
Down
Why does water move through a cell’s membrane?
Water moves to make sure there’s an equal amount of stuff (like salt or sugar) on both sides of the membrane.
What is Osmosis?
Osmosis is the diffusion of water across a selectively permeable membrane
Why is Osmosis important?
Osmosis regulates the water flow through the plasma membrane , which helps maintain homeostasis within a c
ell
what factor affecting transport?
Cell Membrane
The Membrane is Permeable to:
H2O,
Gases( O2 , CO2 ,N2)
Lipids
Small polar neutral (Urea)
What types of molecules is impermeable or less permeable in the cell membrane?
The membrane is less impermeable to small polar molecules, large unchained molecules such as amino acids, glucose, and large molecules( Fatty acids)
what are the two types transport across the membrane?
Active and Passive Transport
where do the active and passive transport move in regards to the concentration gradient?
Active transport is against the concentration gradient
Passive transport is down the concentration gradient
What does Fick’s Law of Diffusion describe?
Fick’s Law of Diffusion describes how substances move from areas of high concentration to areas of low concentration, with the rate depending on the concentration gradient, surface area, and distance.
How does the concentration gradient affect the rate of diffusion according to Fick’s Law?
The rate of diffusion is directly proportional to the concentration gradient; as the difference in concentration increases, the rate of diffusion also increases.
What does biomembrane permeability refer to?
Biomembrane permeability refers to the ability of membranes to allow certain substances to pass through while blocking others.
What is facilitated diffusion, and how does it differ from active transport?
Facilitated diffusion is a passive process that moves substances down their concentration gradient, using transport proteins to help larger or polar molecules cross the membrane without using energy.
What are the two models of facilitated diffusion, and how do they differ?
The two models of facilitated diffusion are the pore channel, which is a hole through the membrane allowing certain molecules to pass, and the carrier channel, where a small molecule carries substances across the membrane, typically for larger or less permeable species
Give 4 Examples for the pores model:
- Potassium Channel
- Aquaporin water channel
- Voltage gated sodium channel
- The Ionophore gramicidin
Give 2 Examples of carrier uniporters:
- The ionophore valinomycin
- The protein carrier of glucose – GLUT1
What are ionophores and what role do they play in ion movement?
Ionophores are molecules (either small antibiotics or synthetic) that help move ions across cell membranes. They act as either carriers or channels, making it easier for ions to pass through. Essentially, they are known as “ion carriers” because they facilitate the transport of ions, helping to maintain balance in cells.
