Even More About Water

1
Even More About Water

• Lesson 2 part 2

2
Mixtures

• Heterogeneous Mixtures
• Parts of the mixture are noticeably different
  from one another
• Homogenous Mixtures
• Evenly distributed, hard to tell the difference
  between one part and another

3
Solutions

• Type of homogenous mixture
• When substances dissolve in another
• Particles are too small to settle out, filtered
  or scatter light

4
Solvent vs Solute

• Water has many properties, but one of the most
  important is that water acts as a UNIVERSAL
  solvent
• Solvent Substance that does the dissolving
• Solute Substance that dissolves in the solvent
• The solubility of a substance is its ability to
  dissolve another substance
• Water is very good at dissolving
• Hot water can hold more solute (can dissolve
  more) than cold water

5
Water The Universal Solvent

• Waters polarity contribute to water as a
  universal solvent
• Salt is part metal, part nonmetal
• Metal and nonmetal bonding form ionic bonds
• Ionic bonds form from IONS
• Elements that have a or charge
• Opposites Attract

6
Ocean

• Ocean is filled with dissolved particles
• Elements that have opposite electrical charges
  are called SALTS
• This makes a Saline solution
• Na, Cl, Sulfate, Magnesium, Calcium, Potassium,
  Bicarbonate
• Distilled water no salinity
• Fresh water is .01 salt or less
• Ocean average is 3.5 salt or more
• Every liter has 1.2 ounces of salt

7
Why is the Ocean Salty?

• Waters excellent ability to dissolve solutes
  means it is carrying materials with it
• Water does the same in all organisms
• Where do these salts come from?
• Fresh water streams contain salts
• Rivers dump into the oceans
• 4 billion tons of salts are emptied into the
  oceans each year
• Water also evaporates
• Leaves behind salts

8
Where else?

• Inside the Earth
• Deep Sea Vents
• From the Atmosphere
• Wind and Rain carry minerals
• Human made
• Only removed by incorporating into rocks,
  sediments and organisms

9
Salinity Marine Organisms

• Marine organisms are designed to live in the salt
  water
• Brackish in between salty or fresh
• Mangrove forests and salt marshes
• Called estuaries
• Where rivers meet oceans
• Many juvenile organisms live here
• Nursery of the Sea
• Also protect coastlines from erosion

10
Regulation of Solute/Water Balance

• Marine organisms go through Osmosis
• Water moves from low salinity (high water
  concentration) to high salinity (lower water
  concentration
• Osmoconformers-
• Do not attempt to control solute/water balance
• Their internal concentration varies as the
  salinity in the water around them changes
• Most can only tolerate a very narrow range of
  salinity

11
Regulation of Solute/Water Balance

• Osmoregulators
• These organisms control their internal
  concentrations
• Can generally tolerate a wider range of
  salinities than osmoconformers
• Some animals require different amounts of salt
  for different life-cycles
• This can be done in a variety of ways such as
  secreting very little urine or using specialized
  glands to secrete salts as examples

12
Salt Organisms

• Osmoregulation Individual cells control the
  balance of water
• Mangroves will release salt from their leaves
• Some sea turtles and marine birds have special
  salt glands that remove excess salt

13
Osmoregulation

• In high salt environments, fish and other
  organisms lose water to the salty sea
• Must drink more water
• Adding more salts
• Need a way to remove the excess salts and
  maintain homeostasis
• Constant internal environment
• Opposite for Freshwater Fish
• This way cells stay the same size

14
Marine Mammals

• Marine MAMMALS
• Do not drink sea water
• Get water from the food they eat and have a
  higher urine salt concentration

15
Density and Marine Organisms

• Maintain neutral buoyancy
• Float, sink

Less dense than water