Lecture 1 Flashcards
INTRO
Cell membrane composition
55% protein
42% lipid
3% carbohydrates
Cell Membrane function
Acts to divide the intracellular and extracellular compartments
Na+ composition
High extracellularly
Low intracellularly
K+ composition
High Intracellularly
Low Extracellularly
Ca2+ Composition
Low intracellular (1mm)
Low extracellularly
Driving force for Ca2+ influx
HCO3-
Acts to buffer against pH changes
Cl- composition
Low intracellularly
Driving force for influx of Cl-
Chloride-secreting cells have high intracellular Cl-
PO4 2- Composition
High intracellularly
Required for ATP
Lipid soluble molecule transport
Move by diffusion
Small molecules and ions transport
Transport proteins
Large molecules transport
Endocytosis
Active transport
Absence of/against electrochemical gradients
Uses pumps
Low turnover - <100 events per second
Electrochemical gradient
The concentration and the electrical potential gradient
Passive transport
Following electrochemical gradient Includes diffusion and electro-diffusion High turnover 10^2/10^3 events er second highly selective Can become situated
Symporters
Two solutes moved in the same direction