L3 Flashcards
Oxygen diffuses from a/n _ cell in the blood stream to the plasma membrane of various cells in the body
endothelial
Almost every nutrient, substance, or even water requires some kind of transport, except _
oxygen
The plasma membrane is a gateway, into things to either enter or exit the cell, which is in the shape of a fluid _
mosaic
If a substance is unable to cross the plasma membrane, then we say the membrane is ___ to them
semi-permeable
Semi-permeability of the plasma suggests that it is _ for the substances that exits and enters it
selective
Nonpolar molecules are selectively permeable. They include: O2, CO2, and…
steroids
Small, uncharged polar molecules can/not easily permeate the plasma membrane
can.
Small, uncharged polar molecules include urea, and _
water
Ions, and large, UNCHARGED polar molecules require transport across a cell membrane. This includes ions such as Na+ or K+, and large, uncharged polar molecules such as _
glucose
Lipids are the plasma membrane for _, required for endo- and exocytosis
vesicles
Cholesterol, lipid bodies that form vesicles, and __ enable substances to cross the plasma membrane
transmembrane proteins
Dropping food colour into a glass changing the colour of the water, is an example of food colouring going __ the concentration gradient
down
Oxygen is found in _ quantities outside the membrane, and in _ quantities inside the cell. This precipitates that oxygen is obligated to go down the concentration gradient
oxygen higher outside (extracellular), lower inside (intracellular)
Na+ is highly concentrated _ of the cell, hoping to move _ the cell. However, active transport needs to take place, with the use of ATP.
Na+ is high in the extracellular fluid, and lower in the intracellular fluid
Another name for intracellular fluid is _
cytosol
The _ gradient is the difference in electrical charge between two regions, such as across the plasma membrane
electrical gradient
The ions that create charged components along the electrical gradient include:
Na+
K+
Cl-_
Ca2+
Where are negative charges at baseline, and conversely, where are positive charges kept? If so, why?
Negative charges typically are within the cell, whereas positive charges are typically outside the cell. This is because the greater number of Na+ and Ca2+ in the extracellular fluid, whereas K+ is typically within the cell
Substances that do NOT have a charge are acted on by _ gradients
CHEMICAL
Why are potassium ions confusing when along the electrochemical gradient?
K+ goes down the concentration gradient by leaving the cell, as well as goes down the ELECTROchemical gradient by leaving the cell. However, K+ is likely to return, or go UP the ELECTRICAL gradient because the general negative charge of the cytosol propels them to come back, making them not having to use active transport to get there
Why is the understanding the chemical and electrochemical gradient important for understanding physiology?
this is how cells function, with electro, chemical, and electrochemical gradients
