Cell Membrane Flashcards
What is a symport?
Secundary transport that lets two molecules at the same time in the same direction
What are the levels of organisation of life?
Atom-molecule-macromolecule-organelle-cell-tissue-organ-organsystem-organism
What are the bodyfluid contents of a body?
60% of body weight, 2/3 intracellular fluid (ICF), 1/3 extracellular fluid (ECF)
What are the reasons for water output?
Insensible loss= lungs/breathing, evaporation from skin
Sensible loss= sweating, feces, urine
What are reasons for water input?
Drinking
Food
Metabolically produced water
What is membrane proteins?
Peripheral proteins- loosely bound to surface, cell surface identity markers (antigens)
Integral proteins- goes through the membrane (transmembrane), transport proteins (channels, pumps)
What is the main solute in ECF and thereby responsible for ECF osmolarity?
Na+
What is an antiport?
Secundary transport of molecules in different directions (one in-one out)
What are the major differences between ICF and ECF?
ICF-more protein, more K+ ions, less Na+ ions, more PO3-
ECF-no protein (except in plasma), less K+ ions, more Na+ ions, more Cl- ions
What are the concequence of isotonic ECF?
None
What is secondary active transport?
Uses the gradient of one ion to let another one through at the same time. No ATP needed
What is osmolarity?
The concentration of solute particles dissolved in the fluid
What makes the cell membrane semi-permiable?
Protein channels
Specific channels allow soecific material across
How does large molecules move through the cell membrane?
Through vesicles and vacuoles
What is the use of membrane carbohydrates?
Cell-cell recognition (ability to distinguish one cell from another)
Antigens
Immune system (basis for rejection of foreign cells)
What does diffusion mean?
Since the universe strives for entropy (disorder) diffusion is movement from high concentration to low concentration