Upload
tanek
View
55
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Chapter 6 and 7. Marine biology Michael Slemp. Polar bear Ursus Maritimus. Native largely within the Arctic circle Largest land carnivore (eats meat) Largest bear (together with Kodiak bear) Born on land, spend most of their time at sea - PowerPoint PPT Presentation
Citation preview
Chapter 6 and 7Marine biologyMichael Slemp
Polar bearUrsus Maritimus
Native largely within the Arctic circle Largest land carnivore (eats meat) Largest bear (together with Kodiak bear) Born on land, spend most of their time at sea The polar bear has an extremely well developed sense of smell,
being able to detect seals nearly 1 mile away and buried under 3 feet of snow
Superbly insulated by up to 4 inches of blubber The white coat usually yellows with age The polar bear is an excellent swimmer and individuals have been
seen in open Arctic waters as far as 200 mi from land With its body fat providing buoyancy, it swims in a dog paddle
fashion using its large forepaws for propulsion
The Water Planet What percentage of the earth surface is covered by
water? 71% of earths surface is covered by water. Can all the earth’s water be used for drinking? The majority of the water that covers the earth is
salt water and can not be used for drinking. Where does most of the drinking water come from? Most of the water that we rely on comes from
underground aquifers and rivers Because drinking water is essential for life, wars and
disputes have occurred over drinking water.
The Water Planet The average depth
of the ocean is 12,238 feet
Challenger Deep in the Mariana Trench is the deepest in the ocean (35, 558 feet)
Mt Everest could fit in the trench and still be 6,527 feet from the surface from the top of the mountain
Water molecule H2OO = Oxygen (one)
H = Hydrogen (two)
Covalent bond between O and H
(covalent = sharing)
Unequal sharing
causing water molecule to be
polar molecule. This
results in positive and
negative ends.
O = negative region
(minus)
H = positive region (plus)
Review - Water molecule H2O
What does “O” stand for?
What does “H” stand for?
What is the name of the bond
between “O” and “H” ?
What type of molecule is
water?
What region is around “O” ?
What region is around “H” ?
Oxygen
Hydrogen
CovalentWhat does
covalent mean?Sharing
What causes polar
molecule?
Polar molecule
Unequal sharingWhat is the result of unequal
sharing?Positive and negative regions
Negative (minus)
Positive (plus)
Water = many H2O molecules
Oxygen is a region with
negative chargeHydrogen is
a region with
positive charge
Opposite charges attracts resulting in creation of a bond
between oxygen of one water molecule and hydrogen of another
water molecule This bond is
called HYDROGEN
BOND
HYDROGEN BOND
Hydrogen bond:
• Weak covalent bond• Easily breaks and reforms• Cumulative strength in
numbers• Causes water to be a
liquid at room temperature (without hydrogen bonds it would be gas)
• Makes water more viscous (viscosity = tendency for fluid to resist a flow)
HYDROGEN BOND
Hydrogen bond:
• Causes surface tension (forms skin-like surface)
• Imagine water strider that walks on the top of the water
• Surface tension also affects how quickly the ocean takes up atmospheric CO2 and releases O into the air
• Think of air pollution in relationship with ocean?
HYDROGEN BOND
Hydrogen bond:
• Causes water cohesion • It means that water
molecules stick together which allows for a more organized structure
• Causes water adhesion• It means that water
molecules stick to other materials
Cohesion = water molecules stick together• Water sticks together• Water flows• Water creates rain drops
Adhesion = water molecules stick to other materials• Water sticks to a knife• Water sticks to spider web• Water sticks to leaves
HYDROGEN BOND
Hydrogen bond:
• When liquid water changes to ice, hydrogen bonds cause unique phenomenon.
• As ice forms, hydrogen bonds cause water molecule to spread apart and rearrange into crystal structure
• This makes ice less dense than liquid water
• This property of water explains why ice floats in water and also why there is volume expansion when liquid water becomes ice
• Floating ice forms a layer that insulates the water below.
• This causes the water below to retain heat and remain liquid.
• Ultimately this water property supports ocean life
Review - waterWhat type of bond is
between “O” and “H” of the same water molecule?
1. What type of bond is the bond between “O” of
one water molecule and
“H” of another water molecule?2. What is the bond’s name?
covalent
1. Covalent2. Hydrogen bond
What property caused by
hydrogen bonds allows water
strides to walk on water?Surface
tensionWhat is cohesion?Water molecules stick together What is adhesion?
Water molecules stick to other materials
What happens with the structure
when water changes to ice?Molecules spread apart
and rearrange into crystal structure
What is denser?
Ice or liquid water?Water, that
is why ice floats in
liquid water.
Solutions and MixturesSolution
molecules of one substance are evenly dispersed among the molecules of another
substance.
Mixture two or more substances are intermingling, yet retain their individual
characteristics water suga
r
Visually you cannot tell there are two different molecules – water and sugar
oil vinegar
Visually you can tell there are two different molecules – oil and vinegar
Solutions water suga
r
SOLVENT• The more
abundant substance in a solution
• Usually a liquid• Water is great
solvent
SOLUTE• The substance
being dissolved
solvent
solute
What do you think? Is seawater solution or mixture? What is the solute and what is the
solvent?
Review -Solutions and MixturesWhen molecules of one
substance are evenly dispersed among the molecules of another
substance, it is called…
When two or more substances are intermingling, yet retain their individual characteristics, it is
called…
Water + sugarCan you visually tell there are two
different molecules – water and sugar?
yes
Oil + vinegar
Can you visually tell there are two different molecules – oil and vinegar?
solution
mixture
What is an example of a
mixture?What is an example of solution?
no
In water-sugar solution, what is solute?
In water-sugar solution, what is solvent?
sugar
water
SalinityIs the total quantity (or concentration) of all
dissolved inorganic solids called ions
• In seawater there are several dissolved salts such as NaCl (sodium chloride) and KCl (potassium chloride)
• Salinity of seawater measures concentration of NaCl, KCl and other dissolved salts
• Salinity is expressed in parts per thousand (symbol ‰ )• The ocean’s average salinity is 35 ‰• Mouths of the rivers entering ocean has salinity near zero• Regions like Red Sea has Salinity more than 40 • To convert salinity to percentages you divide by 10 (for
oceans 3.5%)• Salinity is measured by salinometer (based on the
conductivity of water)
Colligative Properties • Properties of a liquid that may be altered by
the presence of a solute • The properties are: raising boiling point, decrease freezing
temperature, crates osmotic pressure, electrically conductive, slowed evaporation.• Example:• In seawater the solute is NaCl, KCl and other salts• The dissolved salts in the ocean cause saltwater to have a
higher boiling temp than does regular water• As the salinity increases the water resist freezing
Why are seas salty?Salts come from various sources
• Fresh water: from minerals and chemical eroding and dissolving into fresh water which then flows into the oceans
• Waves and surf: help with erosion into the sea• Hydrothermal vents (possible volcanos): bring
minerals into the ocean from the ocean floor • Storms, precipitation and evaporation all have effect
on the amount of salinity that is in the ocean• Salinity and sea water seem to be at a constant (chemical
equilibrium)• Although pH is relatively stable, it changes with depth. It is
due to the amount of Co2 which tends to vary with depth.
Review What is salinity?Is the total
quantity (or concentration) of
all dissolved inorganic solids
called ionsHow is salinity
expressed?Parts per thousand (‰)What is the average
salinity of the ocean?35 ‰
Name example of salt dissolved in the
ocean?NaCl, KClWhat are colligative
properties?Properties of a liquid that may be
altered by the presence of a solute How does solute (salt)
effect the boiling temperature of the
seawater?
How does solute (salt) effect seawater
freezing ?
The boiling temperature of
seawater is higher than
regular water
Increased salinity causes
seawater to resist
freezing Name 3 examples where oceans get their saltiness?Fresh water,
waves and surf, hydrothermal
vent and volcanoes,
storms, precipitation
and evaporation
Diffusion and osmosisIs the tendency for a liquid, a gas, or a solute to
flow from an area of high concentration to an area of low concentration
Diffusion
A great example of diffusion is movement of molecules across a cell
membrane
High concentra
tion of molecule
Low concentra
tion of molecule
Movement of molecules from high to low
Heat can speed up
the rate of diffusion
Diffusion and osmosisis diffusion of water through a semipermeable membrane from an area of lower concentration of water to the area of higher
concentration of water
Osmosis
Semipermeable membrane only allows some molecule cross
• High concentration of molecule (e.g. sugar)
• low water concentration
• Low concentration of molecule (e.g. sugar)
• high water concentration
Osmosis = Movement of water molecules from high to low
Membrane will not let molecules of solute across
Diffusion and osmosisArea with higher concentration of
solute (e.g. sugar) is
considered HYPERTONI
C
Area with lower concentration of
solute (e.g. sugar) is
considered HYPOTONIC
hypertonic
hypotonic
Diffusion and osmosis
Hypertonic = high solute, low
water
Hypotonic =low solute,
high water
Let’s assume cell membrane allows movement of both, solute and waterDiffusion
• Movement of solute from high solute concentration to low solute concentration
• From hypertonic to hypotonic
Osmosis• Movement of water from
area of high water concentration to area of low water concentration
• From hypotonic to hypertonicdiffusion
osmosis
Becomes isotonic(iso=sa
me)
Becomes isotonic(iso=sa
me)
In isotonic solution• No change
In hypotonic solution
• Water enters cell
• Cells swell and burst
In hypertonic solution• Water moves
outside of the cells
• Cells shrivels
Cells in solutions
Passive and active transportPassive
transport• No energy
needed• Molecules
move via diffusion
• Movement from area of higher concentration to lower concentration
Active transport
• Needs energy• Movement
from area of lower concentration to higher concentration
high
low
low
high
energy
ReviewWhat is
diffusion?
What is osmosis?
Movement of liquid, gas or solute from
hypertonic to hypotonic
The area on left is?
The area on right is?
hypotonic – low solute concentration and high water
concentrationhypertonic – high solute concentration and low water
concentration
Movement of water from high
water concentration to
low water concentration
diffusion
osmosis
What is semipermeable
membrane?Membrane that allows only some molecules
to cross
What happens to cells when they are placed in
1.hypotonic or 2.hypertonic solution?1. Cells swell and
burst2. Cells shrinkWhat is passive
transport?
What is active transport?
Diffusion across membrane from high to
low concentration, needs no energy
Movement of molecules across membrane from
low to high concentration, needs energy