Exam 3: Mechanism of Movement Across PM Flashcards
Diffusion
Movement of molecules from HIGH to LOW.
No energy is needed.
Example: exchange of oxygen and carbon dioxide between our blood and lungs.
What kind of solution do animals prefer?
Isotonic
What kind of internal environment do plants prefer?
Hypertonic, because the movement of water into their cells will provide turgor
Facilitated Diffusion
HIGH to LOW
Carrier proteins or Channel
NO ENERGY.
Example: glucose and ions, sodium, potassium and calcium.
Cystic Fibrosis
Faulty chloride channel. Thick and sticky mucus that clogs lung and pancreatic ducts.
Type 1 diabetes
Lack of insulin
Type 2 diabetes
Insufficient insulin receptors
Active Transport
ATP is needed.
From low concentration to high concentration. (against the gradient)
Example: Sodium-potassium pump.
Cotransport
First active transport and the facilitated diffusion.
Example? intestinal cell pump sodium out and then diffuses in carrying glucose in.
Phagocytosis
takes in solids
Example: amoeba feeding, white blood cells engulfing bacteria
Pinocytosis
membrane pinches in liquids.
examples: egg cells in the ovary take in liquid nutrition.
Receptor mediated endocytosis
Molecules attracted to and bind to receptors. Receptors migrate together. Membrane pinches in and molecules are released. Membrane and receptors join PM
How does temperature affect the diffusion rate?
High temps= fast diffusion rate
How does pressure affect diffusion rates?
High pressure, slower diffusion rates.
How does a gradient size affect diffusion?
The larger the gradient size the faster the diffusion.
