Osmoregulation Lecture 2

Question 1

What is an advantage to being an osmoconformer? What is an advantage in which there is never an osmotic gradient between you and then environment?

Answer 1

More energy conservative! You develop a strategy where your cells never shrink and never expand and dont have to worry about it! Way cheaper than osmoregulation!

Question 2

In osmoregulators, large changes outside result in

Answer 2

small changes on the inside!

Question 3

When your exercising your kidney produces an inside environment that has what kind of osmotic concentration?

Answer 3

very high osmotic concentration. This reflects a situation when you need water, therefore the osmotic concentration will be higher (1200mOsm). Increased water permeability.

Question 4

When you have drank to much and need to pee what is the osmotic concentration gradient like now?

Answer 4

It will become lower around (800mOsm). No water permeability.

Question 5

Some cells from the loop of Henle (human kidney) are exposed to environments with varying osmotic concentration over time that can range from 600 to 1200 mOsm. What physiological mechanism allow these to survive these changes in the osmotic environment?

Answer 5

Animals developed different strategies. Some osmoconform and some osmoregulate.

Question 6

Osmoconformers

Answer 6

cells are equal in osmotic pressure to the environment. Mainly found in the ocean.

Question 7

Osmoregulators:

Answer 7

Osmotic pressure of body fluids is homeostatically regulated and usually different from the external environment

Question 8

in osmoconformers large changes on the outside result in

Answer 8

large changes on the inside

Question 9

Do osmoregulators or do osmoconformers have higher cellular osmotic osmolytes?

Answer 9

osmoconformers

Question 10

in osmoconformers cell and tissues can cope with high extracellular osmolarities by

Answer 10

increasing intraceullular osmolarities with compatible osmolytes this maintains cell volume.

Question 11

A flat line represents

Answer 11

a perfect osmoregulator

Question 12

A diagnol line going up represents

Answer 12

a strict osmoconformer

Question 13

what types of strategy does the shark use to help with osmosis?

Answer 13

osmoconformer

Question 14

Common organic osmolytes include

Answer 14

carbohydrates, free amino acids, methyaline, urea and methylsulfonium.

Question 15

Osmoconformers must maintain intraceullular inorganic levels within a range compatible with

Answer 15

protein functions. This involves compatible osmolytes.

Question 16

Types of osmoconformers:

Answer 16

stenohaline

Euryhaline

Question 17

Stenohalie

Answer 17

Unable to respond to large changes in the environment. Restricted to a narrow range of salinity.

Question 18

euryhaline

Answer 18

Tolerant of changes in salinity. Regulate organic osmolytes in their cells.

Question 19

what animal is an example of a euryhaline?

Answer 19

mosquito

Question 20

What type of osmoconformer would do well in an intertidal zone?

Answer 20

euryhaline

Question 21

euryhaline relies of what for their tolerance of changes to salinity.

Answer 21

osmolytes!

Question 22

If an animal does not use compatible osmolytes what does this restrict them too and talk about an example of this.

Answer 22

If it does not use compatible osmolytes it can only surivive in a single type of environment. Example is halobacterium lives in high salinity. Its strategy instead of compatible osmolytes requires massive amino acid subsitution in thousands of proteins

Question 23

So if an animal does use compatible osmolytes what kind of an advantage does this give them and give an example of an organism that lives better than halobacterium?

Answer 23

Compatible osmolytes gives an advantage of being able to tolerate a wide range of salinity. Dunaliella is a euryhaline and lives in a wide range of salinites.

Question 24

How does a mosquito know when it needs to increase protein concentration (protein concentration increases when the environment becomes more salty, proteins are the osmolytes.)

Answer 24

Scientist proposed the mosquito was sensing it with the environmental ions. When the mosquito was exposed to sea water the animal was exposed to sodium and chloride, and she was able to prove that it starts to osmoconform when it senses these changes. Not sorbitol

Question 25

What is the only vertebratethat is not a osmoregulator?

Answer 25

shark

Question 26

Are sharks stenohalines or euryhalines?

Answer 26

stenohalines

Question 27

What 2 molecules do sharks use and how are they unique to each other?

Answer 27

Sharks maintain a high concnetration with urea, however it also uses trimethylamine - N-oxide (TMAO). These two molecules are not compatible but when together they become compatible. The effect of urea is counteracted by TMAO.

Question 28

what does urea act as in sharks?

Answer 28

compatible osmolyte

Question 29

Euryhaline sharks that penetrate fresh water use what type of strategies to maintain osmolarity concentrations?

Answer 29

They have osmoregulatory strategies.

Question 30

What happens to a bull shark when it decides to live in freshwater for a bit?

Answer 30

Water rushes into the shark therefore the shark has to pee it out. Producing 20 times more urine. This is very energetically expensive.