Adaptations to Aquatic Environment

At what temperature does pure water become solid?

0 degrees C

At what temperature does pure water become a vapor?

Above 100 degrees C

When is water the most dense?

4 degrees C

What happens to the freezing temperature of water when it contains dissolved compounds?

It drops below 0 degrees C

What type of specific heat does water have?

It has a high specific heat

What does water having a high specific heat mean?

Makes it resistant to changing states
Helps prevent water bodies from freezing completely solid during the winter

Why can ice float?

It floats due to its crystalline structure

What level of viscosity does water have?

It has a high viscosity

What are some ways that some organisims have evolved to deal with water’s high viscosity?

Streamlined bodies that reduce the drag

Long, filamentous appendages that increase drag

What are some of the dissolved inorganic nutrients that aquatic organisms need to build organic compounds?

Hydrogen

Carbon

Oxygen

Nitrogen

Phosphorus

Potassium

Calcium

What does precipitation do regarding minerals?

It dissolves some of the minerals in rocks and soils, and carries them through streams and to the ocean

What happens to the minerals beyond saturation?

They precipitate out of the water

Water with a low pH

Acidic

Water with a medium pH

Neutral

Water with a high pH

Basic/Alkaline

What can acidic water do?

It can dissolve toxic metals and negatively affect enzyme activity

What is a common strategy to adapt to the salinity of an environment?

Change the osmotic potential of body fluids by synthesizing large quantities of organic solutes

How do some aquatic animals maintain salt balance?

Maintaining some urea in the bloodstream, which raises the osmotic potential of their blood to that of seawater

How do some aquatic animals protect their proteins from the harmful effects of urea?

They accumulate trimethylamine oxide

What can the low solubility and slow diffusion of O2 do?

It can limit the metabolism of organisms that obtain O2 from the water

What is thermal optima determined by?

The properties of an organism that influence the ability to function

What can heat do to biological molecules?

Change their shape
Accelerate chemical reactions

Can cause them to become less stable

Can impair their functions

Can denature them

What can the crystal structure of ice do to living cells?

It can damage them