Plasma Membrane and Diffusion Flashcards
Remeber defintions
What is osmosis?
The passive movement of water molecules from an area of low solute concentration to an area of high solute concentration across a semi-permeable membrane until the concentrations are equal.
Osmosis is crucial for maintaining cell turgor and function.
What are the characteristics of fatty acid tails?
Hydrophobic and non-polar.
Fatty acid tails repel water, which affects membrane structure.
What are the characteristics of phosphate heads?
Hydrophilic and polar.
Phosphate heads attract water, contributing to membrane formation.
What is diffusion?
The passive movement of molecules from a high solute concentration to a low solute concentration across a semi-permeable membrane until equally dispersed.
Diffusion is a key process in cellular transport.
What does hypertonic mean?
Has a high concentration inside the cell and low in the solution.
This condition can lead to cell shrinkage.
What does hypotonic mean?
Has a low concentration inside the cell and high in the solution.
This condition can cause cells to swell or burst.
What does isotonic mean?
The same concentration of solute in solution and cell.
Isotonic conditions are ideal for cell stability.
What happens to a plant cell when it is hypertonic?
It becomes plasmolysed.
Plasmolysis can lead to cell damage.
What happens to an animal cell when it is hypertonic?
It becomes shriveled.
Shrinkage can impair cell function.
What happens to a plant cell when it is isotonic?
It becomes flaccid.
Flaccidity can affect the plant’s structural integrity.
What happens to an animal cell when it is isotonic?
It is normal.
Normal conditions allow for proper cellular function.
What happens to an animal cell when it is hypotonic?
It is lysed.
Lysis can result in cell death.
What happens to a plant cell when it is hypotonic?
It is turgid.
Turgidity is important for plant structure.
What role does a carrier protein play?
Assists in carrying large polar molecules across the membrane.
Carrier proteins are essential for transporting substances that cannot diffuse freely.
What are non-polar molecules?
Uncharged and repel water.
Non-polar molecules can easily cross lipid membranes.
What is facilitated diffusion?
The transport of polar molecules via specific proteins.
Facilitated diffusion does not require energy.
What is passive transport?
The movement of substances that doesn’t require energy.
Passive transport includes diffusion and osmosis.
How is the Fluid Mosaic model defined?
Free and flexible.
This model describes the dynamic nature of cell membranes.
What do receptor proteins or glycoproteins do?
Bind hormones and other substances that cause changes to cell activities.
Receptor proteins are vital for cell signaling.
What is the function of transport proteins?
Form channels for substances to move across the membrane.
Transport proteins are crucial for selective permeability.
What are integral proteins?
Proteins embedded in the membrane.
Integral proteins play roles in transport and signaling.
What are transmembrane proteins?
Proteins that are embedded in the membrane and span to the outside.
Transmembrane proteins often serve as channels or receptors.
What are peripheral proteins?
Proteins that float on the outside.
Peripheral proteins typically play roles in signaling and maintaining the cell’s shape.
What role does cholesterol play in membranes?
Improves stability among phospholipids.
Cholesterol helps maintain membrane fluidity and integrity.
