Unit 2 Structure And Function Flashcards
(59 cards)
What is the function of the cell membrane?
A selectively permeable barrier that regulates what enters and exits the cell
It allows O2, nutrients, and waste to pass through.
What are the two types of proteins found in the cell membrane?
- Peripheral proteins
- Integral proteins
Define ‘amphipathic molecules’.
Molecules that have both hydrophilic and hydrophobic regions.
What is compartmentalization in a cell?
The separation or bringing together of cellular components to increase efficiency.
What is water potential?
The ability of water molecules to move freely in a solution.
What is the water potential of distilled water?
0 bars (high water potential).
What happens to water in a hypertonic solution?
Water moves out of the cell, leading to cell shrinkage.
Define osmoregulation.
The control of water movement in and out of cells.
What does plasmolysis refer to?
Loss of water from a cell, causing it to shrink.
What is the formula for total water potential?
Ψ = Ψp + Ψs
What does Ψs represent in the water potential equation?
Solute Potential, calculated as Ψs = -iCRT.
What does the variable ‘i’ stand for in the solute potential equation?
Ionization constant (number of particles the solute breaks into).
What is the relationship between surface area and volume in cells?
As cells grow larger, volume increases faster than surface area, decreasing the surface area to volume ratio.
What is passive transport?
Movement of molecules across the membrane without energy input.
What is facilitated diffusion?
Passive transport aided by transport proteins.
What is active transport?
Movement of molecules against their concentration gradient, requiring energy.
What is the function of electrogenic pumps?
To generate voltage across a membrane for cellular work.
What is cotransport?
When one molecule’s transport indirectly drives the transport of another molecule.
What is exocytosis?
Process of transporting large molecules out of the cell.
What is endocytosis?
Process of taking in macromolecules by forming vesicles from the plasma membrane.
Differentiate between phagocytosis and pinocytosis.
- Phagocytosis: cell ‘eating’ large particles
- Pinocytosis: cell ‘drinking’ extracellular fluid
What is the function of the Golgi apparatus?
To modify, sort, and package proteins and lipids for transport.
What are lysosomes?
Membrane-bound sacs of hydrolytic enzymes used for digestion.
What is apoptosis?
Programmed cell death facilitated by lysosomal enzymes.
