Physiology ToS questions B Flashcards
Explain different transport mechanisms for solutes and other substances in the cell
Generally, what are the substances that are transported across the cell membrane? (9)
Gases
Water
Alchohol
Glucose (sugars)
Amino acids
Nucleoside
Proteins
Lipids
Ions
What are the three major transport mechanisms that occur in plasma membrane?
Passive transport
Active transport
Special mechanisms (2)
A type of membrane transport of substrates that does not require energy to move substances across cell membranes. This relies on the second law of thermodynamics to drive the movement of substances across cell membranes, Fick’s first law: from an area of high concentration to an area of low concentration.
Passive transport
What are the three mechanism under passive transport that occurs in plasma membrane?
Simple diffusion
Facilitated diffusion
Osmosis
This is one of the three types of passive transport where net transfer of molecule down electrochemical gradient
Simple diffusion
This is one of the three types of passive transport where there is carrier molecules but still no energy is required for transfer of molecules. “choosy”, “not like other passive transport”
Facilitated diffusion
This is one of the three types of passive transport where this focuses on the flow of water across a semi-permeable membrane, but still following the Fick’s law
Osmosis
A type of membrane transport where the net movement of substrates is against the electrochemical gradient, thus requiring energy.
Active transport
What are the three mechanism under active transport that occurs in plasma membrane?
Primary active transport
Secondary active transport
Exocytosis
This is one of the three mechanisms of active transport where the movement of molecules against their concentration gradient using ATP as the energy source, usually using pumps and transporters
Primary active transport
This is one of the three mechanisms of active transport where the movement of molecules against their concentration gradient using energy created by concentration gradient as the energy source, usually using co-transport mechanism
Secondary active transport
What are examples of solutes transported via secondary active transport which means this depends on sodium gradient? (2)
Non-electrolytes:
Sugars
Amino acids
What are the two mechanism under special mechanism that occurs in plasma membrane?
Vectorial metabolism
Osmoregulation
This is one of the two mechanisms of special mechanism which specifically focuses comparison of glucose uptake to sucrose. It being that sucrose being the faster energy source
Vectorial metabolism
This is one of the two mechanisms of special mechanism which specifically focuses on the cell’s ability to regulate osmotic pressures and maintain proper solute concentration
Osmoregulation
What are the specific transport mechanism of importance? (3)
Sodium pump (Na-K-ATPase)
Chloride ion transport
Calcium transport
This transport mechanism of importance is a system which is responsible for the asymmetrical distribution of sodium and potassium across the cell (3:2 ratio respectively). This is a form of secondary active transport
Sodium pump/Na-K-ATPase
What is the importance of sodium pump? (4)
-Maintains cell volume
-Maintains cells resting potential
-Nerve cells depends on this for respond-stimuli and
-Impulse transmission
This transport mechanism of importance is a system which focuses on translocation of chloride ions
Chloride ion transport
What is the importance of chloride ion transport? (6)
-Regulates intestinal chloride-bicarbonate exchange
-Has roles in voltage gated channels
-Immune defense due to role in generation hypochlorous acid by myeloperoxidase
-Acid-base balance
-Electrolyte balance
-Developmental processes (NKCC1 & KCC2)
-Neurotransmitter transport
What are the two ways that causes chloride ion translocation?
Hamburger effect
Active transport
What happens in Hamburger effect involving chloride ion translocation?
Chloride is exchanged with bicarbonate
What happens in active transport involving chloride ion translocation? (2)
-energy from active chloride transport= sodium electrochemical gradient that is maintained by sodium pump
-Active transport + sodium pump
This transport mechanism of importance which is analogous to Na-K-ATPase. Important for reducing calcium concentration in cytosol of muscle cells for relaxation
Calcium transport
This is a type of transport mechanism that is similar to simple diffusion but the rate of diffusion is altered by the structure and composition of the membrane through which diffusion occurs
Restricted diffusion
This is the term used for when water moving in bulk can accelerate or impede solute transfer if both move through the same channel
Solvent drag
How are macromolecules transferred across the membrane? (2)
Endocytosis
Exocytosis
What are examples of macromolecules that may be transferred through cell membrane via endo- or exo- cytosis? (3)
Proteins
Carbohydrates
Polysaccharides
This is a type of endocytosis which can selectively internalize physiologically significant proteins
Receptor mediated endocytosis
What is an example of receptor mediated endocytosis?
Ingestion of cholesterol by mammalian cells for synthesis of new membranes
What do you call the pits on the cell membrane of plasma where ligands bind with special vesicles to
Clathrin-coated pits
Generally what are the 8 examples of electrolytes found the body?
Na+ (sodium)
K+ (potassium)
Ca++ (calcium)
Mg++ (magnesium)
Cl- (chloride)
HCO3- (bicarbonate)
Phosphates
SO4- (sulfates)
Generally, what are the 10 examples of non-electrolytes found in the body?
Phospholipids
Cholesterol
Neutral fat
Glucose
Urea
Lactic acid
Uric acid
Creatinine
Bilirubin
Bile salts
