Download Isotonic Hypotonic Hypertonic

Chemistry of Life (157 – 163)
6.3
Cell Processes
Active and Passive Transport,
Osmosis, Diffusion, Exocytosis, and
Endocytosis
pp. 155 – 156; 195 -200
6.2, 8.1
Hickox: Baker High School Biology
Most membranes
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involve
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molecules.
four main
biochemicals:
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Objective 2.0:
Describe cell processes necessary for achieving homeostasis, including active and passive transport, osmosis,
diffusion, exocytosis, and endocytosis
•
Identifying functions of carbohydrates, lipids, proteins, and nucleic acids in cellular activities
•
Comparing the reaction of plant and animal cells in isotonic, hypotonic, and hypertonic solutions
•
Explaining how surface area, cell size, temperature, light, and pH affect cellular activities
•
Applying the concept of fluid pressure to biological systems
Examples: blood pressure, turgor pressure, bends, strokes
Core concept:
Vocabulary
Most cell functions involve chemical reactions. Food molecules taken into cells react to
provide the chemical constituents needed to synthesize other molecules. There are four
main biochemicals: Carbohydrates, Proteins, Lipids and Nucleic acids. Cells use
carbohydrates to provide energy. Cells use proteins for cellular construction and repair,
cellular chemical activities, and as a back-up energy source if carbohydrates are not
available. Both breakdown and synthesis are made possible by a large set of protein
catalysts, called enzymes. Cells use lipids for cell membrane construction. Cells use
nucleic acids to store genetic information for protein synthesis.
•
•
•
•
•
Core concep: Cell membranes are selectively permeable. This gives them the
ability to maintain cell homeostasis by regulating what enters and leaves the
cell. The direction of water movement across the cell membrane depends on
the relative concentrations of free water molecules in the cytoplasm and in the
fluid outside the cell. Different kinds of cells have evolved different ways of
dealing with hypertonic, hypotonic, and isotonic solutions. The cells of plants
have rigid cell walls that keep the cells from expanding too much. Animal cells
can avoid swelling by moving dissolved particles from the cytoplasm.
Carbohydrate
Nucleic Acid
Lipids
Proteins
Enzyme
Vocabulary
• Passive transport
•Active transport
•Endocytosis
•Isotonic
•Exocytosis
•Diffusion
•Hypotonic
•Hypertonic
•Homeostasis
•Osmosis
Core Concept:
Small cells function more efficiently than large cells. Small cells can exchange
substances more readily than large cells because small objects have a higher
surface-area-to-volume ratio than larger objects. Most cells function best within a
narrow range of light, temperature and pH. At very low temperatures, reaction
rates are too slow. Extremes of light, temperature and pH can irreversibly change
the structure of most protein molecules. Vocabulary: pH, surface area, volume
Turgor pressure is the main pressure of the cell contents against the cell wall in
plant cells and bacteria cells, determined by the water content. Blood pressure
refers to the force exerted by circulating blood on the walls of blood vessels.
High blood pressure can cause stroke.
Breathing gas under pressure can present a myriad of possible medical problems.
One of these is decompression sickness or "the bends," caused by breathing
nitrogen or other gases under pressure, which are not metabolized by the body.
Vocabulary
• Bends
• Stroke
Hickox: Baker High School Biology
Simple to Complex
Life’s Levels of Organization
Our journey begins here, atoms like Hydrogen (H)
and Oxygen (O)
Atoms come together to male up
molecules like water, H2O.
Hickox: Baker High School Biology
Chemical Reactions
REACTANTS
Sun
CO2
+
H2O
CHEMICAL
EQUILIBRIUM
PRODUCT(S)
C6 H12 O6 + 02
Acids and Bases
• Acids are substances that forms in water and
release hydrogen ions (H+).
• Bases are substances that either take up
hydrogen ions (H+) or release hydroxide ions
(OH-).
• pH measures how acidic or basic a solution is
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pH Scale
• A pH scale is used to indicate how acid and
basic of a solution.
– Ranges from 0-14
• 7 = Neutral
• >7 = Base
• <7 = Acid
Hickox: Baker High School Biology
Hickox: Baker High School Biology
pH Matters
A strong acid is pH of 2
pH is a measure of
proton (hydrogen ion or
H+) concentration .
Low pH = lots of H+s,
high pH = few H+s.
In biology, keeping H+
levels within a narrow
range is critically
important.
A strong base is pH of 12
Essential Question
What are differences and similarities of Osmosis
and Diffusion?
Hickox: Baker High School Biology
VIDEO
FROM FILE
Diffusion
Diffusion is the net movement of
particles from an area of higher
concentration to an area of lower
concentration.
Diffusion continues until there is no
concentration gradient!
What affects the speed of Diffusion?
• concentration: main factor, higher the more
• temperature: if temp. increase greater diffusion
• pressure: increasing pressure increases diffusion
Dynamic equilibrium
no concentration
gradient!
Dynamic equilibrium
Osmosis
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13
Your turn:
Compare Osmosis and Diffusion
Osmosis
Diffusion
Hickox: Baker High School Biology
Osmosis
• Isotonic Solution - Solute and Solvent (water)
concentrations both inside and outside the
membrane are equal.
• Hypotonic Solution - Solution with a lower
concentration of solute than the solution on
the other side of the membrane.
– Cells placed in a hypotonic solution will swell.
• Lysis
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15
Osmosis
• Hypertonic Solution - Solution with a higher
concentration of solute than the solution on
the other side of the membrane.
– Cells placed in a hypertonic solution will shrink.
• Plasmolysis
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16
The results of diffusion
When a cell is in dynamic
equilibrium with its
environment, materials move
into and out of the cell at
equal rates. As a result,
there is no net change in
concentration inside or
outside the cell.
Material moving
out of cell equals
material moving
into cell
What type of osmosis is this?
(Isotonic, hypotonic, or hypertonic)
Does cell shrink, expand, or stay the same?
What type of osmosis is this?
(Isotonic, hypotonic, or hypertonic)
Does cell shrink, expand, or stay the same?
What type of osmosis is this?
(Isotonic, hypotonic, or hypertonic)
Does cell shrink, expand, or stay the same?
VIDEO
FROM FILE
Your Turn: OSMOSIS
______________ is the diffusion of particles through a semipermeable membrane.
__________________: movement of particles across cell
membranes by diffusion or osmosis. The cell uses NO energy to
move these particles
__________________: the transport of materials against the
gradient and this takes energy
___________________: the pushing out of water in a plant cell
against the cell wall
___________________: shrinking of cell due to water moving out
(dissolved solution outside cell high)
_____________: swelling of a cell due to water moving in
____________: concentrations inside and outside cell is balanced.
Diffusion in Living Systems: the way cells move substances in and
out of the cell
Osmosis is the diffusion of particles through a semi- permeable
membrane.
Hypotonic
Isotonic
Hypertonic
Essential Question
What are the essential molecules of Life?
Hickox: Baker High School Biology
Biomolecule: Structures vary
RINGS
Three views of glucose, a common simple sugar.
BUNCHED CHAINS
amino acids
lipids
LONG CHAINS
Molecules of Life
How do you build a cell?
Start with water, add lots of small carbon-containing
molecules and …….
Use these four major classes of biological molecules:
Carbohydrate, lipid, protein, nucleic acid.
Carbohydrates
Carbon, Hydrogen, and Oxygen
Carbohydrates are used for energy and to create structures.
The building blocks for carbohydrates are simple sugars.
Three views of glucose, a common simple sugar.
Lipids are large and are made mostly of carbon and
hydrogen and small amounts of oxygen.
Fat
Lipids do not
dissolve in water.
Lipids are used
by cells for
energy storage,
insulation, and
protective
coatings, such as
in membranes.
Phospholipid
Phospholipids Form Double-Layered Biological Membranes
Protein p. 66
Proteins are THE key elements
of life.
Proteins provide structure for tissue and organs and
carry out cell metabolism. Provide the body with the ability to
move muscles. They are needed to transport oxygen in the
bloodstream. Proteins are large and complex; made of carbon,
hydrogen, oxygen, nitrogen and sometimes sulfur.
Enzymes, a type of protein that change the speed of
chemicals reactions in the body.
An enzyme (p. 66) is a protein that enables other
molecules to undergo chemical changes to form new
products. Enzymes increase the speed of reactions that
would otherwise proceed too slowly.
Substrate
Active
site
Strands of the Protein Keratin Create Hair
Nucleotides are Chains of Linked Amino Acids
DNA and RNA
The building blocks of proteins
are amino acids!
There are two kinds of nucleic
acids, DNA and RNA. Both are
involved in the storage and flow of
information from gene to gene
product.
Nucleotides Are the
Monomers That
Create Polymers of
DNA and RNA
The small subunits that
make up nucleic acids
are nucleotides.
DNA
Hickox: Baker High School Biology
RNA
Mader: Biology 8th Ed.