Ion and Water Balance 2 Flashcards
how are solutes classified
- by their effects on macromolecules
what are the classifications of solutes (3)
- perturbing
- compatible
- counteracting
perturbing solutes (2)
- disrupt macromolecular function
- change structure/function of proteins/enzymes
perturbing solutes: examples (5)
- Na+
- K+
- Cl-
- SO4+
- charged amino acids
compatible solutes
- little affect on macromolecular function
compatible solutes: examples (2)
- polyols (glycerol, glucose)
- uncharged amino acids
counteracting solutes (2)
- disrupt function on their own
- counteract disruptive effects of other solutes when employed in combination
counteracting solutes: examples (2)
- urea
- TMAO
Km
- affinity of an enzyme for a substrate
what do changes in Km indicate
- changes in Km allude to disruptions in enzyme function
epithelial tissue (2)
- form boundary between animal and environment
- involved in physiological functions such as respiration, digestion, and ion and osmoregulation
how do animals compensate for passive ion and water movements
- active transport of ions across osmoregulatory epithelia
what are the primarily osmoregulatory epithelia of vertebrates (3)
- gills
- kidney
- digestive system
why is drinking salt water lethal for humans (2)
- urine is less concentrated then sea water
- will lead to dehydration
what is a function unique to the kidneys of birds/mammals
- produce concentrated (hyperosmotic relative to blood) urine
marine elasmobranch
- blood [ ] relative to environment
- urine [ ] relative to blood
- slightly hyperosmotic
- isoosmotic
marine elasmobranch: osmoregulatory mechanisms (2)
- does not drink seawater
- hyperosmotic NaCl from rectal gland
marine teleost:
- blood [ ] relative to environment
- urine [ ] relative to blood
- hypoosmotic
- isoosmotic
marine teleost: osmoregulatory mechanisms (2)
- drinks sea water
- secretes salt from the gills
freshwater teleost:
- blood [ ] relative to environment
- urine [ ] relative to blood
- hyperosmotic
- hypoosmotic
freshwater teleost: osmoregulatory mechanisms (3)
- drinks no water
- absorbs salt with gills
- produces large quantities of urine
amphibian:
- blood [ ] relative to environment
- urine [ ] relative to blood
- hyperosmotic
- hypoosmotic
amphibian: osmoregulatory mechanisms
- absorbs salts through skin
marine reptile:
- blood [ ] relative to environment
- urine [ ] relative to blood
- hypoosmotic
- isoosmotic
marine reptile: osmoregulatory mechanisms (2)
- drinks seawater
- hyperosmotic salt-gland secretion
desert mammal:
- urine [ ] relative to blood
- hyperosmotic
desert mammal: osmoregulatory mechanisms (2)
- drinks no water, depends on metabolic water instead
- produces concentrated urine to conservewater
marine mammal:
- blood [ ] relative to environment
- urine [ ] relative to blood
- hypoosmotic
- hyperosmotic
marine mammal: osmoregulatory mechanisms
- does not drink seawater
marine bird:
- urine [ ] relative to blood
- hyperosmotic
marine bird: osmoregulatory mammal (2)
- drinks seawater
- hyperosmotic salt-gland secretion
why can marine birds drinks seawater (2)
- their kidneys alone cannot produce more concentrated urine than seawater
- additional salt secretion gland allow for birds to handle seawater
terrestrial bird:
- urine [ ] relative to blood
- hyperosmotic
terrestrial bird: osmoregulatory mechanism
- drinks freshwater
what are the properties of epithelial tissue that allows for ion movement (4)
- asymmetrical distribution of membrane transporters
- cells are interconnected to form an impermeable sheet of tissue
- high cell diversity within tissues
- mitochondria-rich cells to provide ATP for transport
what terms describe the asymmetrical distribution of membrane transporters (2)
- apical membrane
- basolateral membrane
what helps epithelial cells form an impermeable sheet
- tight cell-cell junctions
what are main routes of solute transport in epithelial cells (2)
- transcellular transport
- paracellular transport
transcellular transport
- movement through the cell
paracellular transport
- movement between cells in “leaky epithelia”
what are the types of solute transporters (4)
- electrogenic Na+/K+ ATPase (NKA)
- various solute-specific channels (Cl-, K+, Na+)
- electroneutral cotransporters
- electroneutral exchangers
osmoregulation in freshwater fish: passive movement (2)
- gain of water
- loss of ions across gill and gut
osmoregulation of freshwater fish: active movement (2)
- produce lots of dilute urine in kidney to get rid of water
- active absorption of ions at the gill
osmoregulation in marine fish: passive movement (2)
- loss of water
- gain of ions across gill and gut
osmoregulation in marine fish: active movement (3)
- cannot produce concentrated urine to conserve water
- drinks to obtain water
- actively secretes ions at the gill
what do fish cells possess for osmoregulation
- ionocytes
where are ionocytes located in fish gills (2)
- filaments
- lamellae
ionocyte function
- cells that regulate and transport ions
how do ionocytes transport ions (2)
- cells are generally mitochondria-rich
- high levels of Na+/K+ ATPase to actively drive ion movement
how do gills move ions in marine fish
- excrete ions
how do gills move ions in freshwater fish
- uptake ions
what is the driving force for ion regulation in marine and freshwater gills (2)
- Na+/K+ ATPase
- it is used to establish a negative potential inside the cell
what cells assist in ion movement in freshwater gills (2)
- PNA- cells
- PNA+ cells
freshwater fish gills: PNA- cell function
- Na+ uptake from the environment into the cell/blood
freshwater fish gills: PNA- cell basolateral transporters (3)
- electrogenic Na+/K+ ATPase creates negative charge inside cell and transports Na+ into the blood stream
- Na+/HCO3- cotransporter further moves Na+ into the bloodstream
- CO2 diffuses into the cell to be converted into HCO3- and H+ by carbonic anhydrase
freshwater fish gills: PNA- cell apical transporters (3)
- Na+ transporter is opened for Na+ transport into the cell
- H+/Na+ exchanger further drives Na+ into the cell
- H+ from carbonic anhydrase reaction is removed from the cell to further create negative charge
freshwater fish gills: PNA+ cell function
- Ca2+ and Cl- uptake from the environment into the cell/blood
freshwater fish gills: PNA+ cell basolateral transporters (6)
- Ca+ transporter to move Ca+ into the blood
- Ca+/Na+ exchanger to move Ca+ into the blood
- Na+/K+ ATPase to establish negative potential inside cell
- H+ transporter to remove H+ from the carbonic anhydrase reaction
- CO2 diffuses into the cell to be converted into HCO3- and H+ by carbonic anhydrase
- Cl- transporter to move Cl- into the blood
freshwater fish gills: PNA+ cell apical transporters (2)
- Ca2+ ATPase to move Ca2+ from the environment into the cell
- Cl-/HCO3- exchanger to move Cl- into the cell from the environment
marine fish gills: ionocyte basolateral transporters (4)
- Na+/K+ ATPase creates negative electrical potential inside cell
- Na+/K+/2Cl- cotransporter moves ions into the cell
- K+ transporter moves K+ back into the blood
- Na+ is moved out of the gills by paracellular transport between cells
marine fish gills: ionocyte apical transporters
- Cl- transporter moves Cl- from the cell into the environment
diadromous fish
- fish that move between fresh and seawater during their life cycle
what are the classifications of diadromous fish (2)
- catadromous
- anadromous
catadromous fish (2)
- adults live in freshwater
- breeding occurs in seawater
anadromous fish (2)
- adults live in seawater
- breeding occurs in freshwater
what is the term used to describe fish that move between seawater and freshwater in their life cycle
- diadromous
what is the life cycle of salmon (6)
- eggs
- alevin
- fry
- parr
- smolt
- adult
in what stage of the life cycle do salmon transition from marine to freshwater
- in the smolt phase
what is the first stage of the anadromous smolting salmon (3)
- metabolic changes
- initiation of smoltification
- growth acceleration
what is the second stage of the anadromous smolting salmon (4)
- morphological changes
- silvering
- outmigration
- homing imprinting
what is the third stage of the anadromous smolting salmon
- seawater tolerance
what hormones change during salmon smoltification (5)
- thyroxine
- insulin
- estradiol
- cortisol
- catecholamine
how does thyroxine change during salmon smoltification
- increases dramatically, peaks in the middle of the process, before falling again
how does insulin change during salmon smoltification
- rises slighting, before falling
how does estradiol change during salmon smoltification
- slight increase in the middle of the process
how does cortisol change during salmon smoltification (2)
- gradual increase, with peak near the end of the process
- most important hormone in process
how does catecholamine change during salmon smoltification
- stays low and begins to rise near the end of the process, with peak occurring after the process ends
which protein isoform is associated with freshwater in salmon gills
- NKAα1a
what protein isoform is associated with seawater in salmon gills
- NKAα1b
