Transcript Cell Processes

Cell Transport
S. Dickinson
HHS
Biology
How do “smells” get out of the
balloon?
• Diffusion
• Selectively permeable membrane
• Homeostasis
• Active transport
• Hypertonic/hypotonic/isotonic
• Osmosis
Concentration
• The mass of a solute in a given volume of
solution
• If you dissolve 12 grams of salt in 3 liters
of water, what is the concentration of salt
in the solution?
• 12g/3L = 4g/L
• Suppose you add 12 more grams of salt in
to the solution. What would be the
resulting concentration?
• 12g + 12g = 24 g
• 24g/3L = 8g/L
• What if you then added another 3 liters of
water to that solution. What would be the
resulting concentration?
• 3L + 3L = 6L
• 24g/6L = 4g/L
4g/L; 8g/L; 4g/L
• Which solution would be called the most
concentrated?
• 8g/L
• Why?
– 8g in 1L is more than 4g in 1L
Selectively Permeable
• A membrane through which some
substances can pass through, but some
cannot
Diffusion
• Movement of particles from an area of high
concentration to an area of low concentration
• Particles try to reach equilibrium/homeostasis
• Equilibrium/homeostasis is reached when the
concentration of the solute is the same
throughout the system
Diffusion
• Substances diffuse across membranes
without requiring the cell to use energy
• Particles of a solution continue to move
across the membrane even when
equilibrium is reached, there is just no
further change in concentration
Passive Transport
• Does not require energy
Active Transport (Fig. 7-19)
• Movement of materials against the
concentration gradient
• Requires energy
• Generally carried out by transport proteins
in cell membrane
• Can be used to transport calcium,
potassium, and sodium ions across the
membrane
Endocytosis
• Membrane infolds to take in materials
• Pocket breaks loose to form vacuole in
the cytoplasm
– Phagocytosis: taking in food; amoeba's use
this to take in food
– Pinocytosis: membranes form pockets that fill
with water and break off as vacuoles in the
cytoplasm
Exocytosis
• Membrane of vacuole fuses with cell
membrane
• Forces contents out of cell
Facilitated Diffusion
• Does not require energy but does require
a protein channel
• Movement from high [] to low []
Osmosis
• Diffusion of water through a selectively
permeable membrane
• Water moves from an area of high water
concentration to an area of low water
concentration
Osmosis Cartoon Project
• Draw an Osmosis Cartoon Project on the
left side
Biomolecule Foldable
• Make a foldable like the Organelle
Foldable only this time you need 4 flaps
• You will write the Polymer/Biomolecule on
the outside with a picture representation.
On the inside, you will have the function
on the side not cut and the monomer with
a picture on the side you cut.
Carbohydrates
Made up on carbon, hydrogen, and
oxygen
 Body’s main source of energy
 Can also be used for structural purpose
 Sugars

Monosaccharides
Single sugars
 Ex: glucose, galactose, fructose

Disaccharides
Two monosaccharides bound together
(Monomer = monosaccharide; polymer =
monosaccharides bound together.
 Ex: lactose (glucose and galactose),
sucrose (glucose and fructose), and
maltose (two glucose molecules)
 Monomer – building block of a molecule
 Polymer – the “building” or actual
molecule

Polysaccharide
Thousands of monosaccharides linked
together
 Ex: glycogen, starch cellulose

Lipids
Made mostly of carbon and hydrogen
 Not soluble in water
 Consists of fats, oils, and waxes
 Can be used to store energy
 Many lipids are formed with glycerol and a
fatty acid tail
 Steroids are lipids

Saturated
Lipid with only single bonds
 “Saturated with hydrogens”
 Solid at room temperature
 Ex: animal fat (lard), fatty meats

Unsaturated
Has at least one double bond
 Liquid at room temperature
 Ex: vegetable oil, olive oil, canola oil

Polyunsaturated

Many double bonds (more than one can
be considered polyunsaturated)
Nucleic Acids





Nucleotides joined covalently
Contain carbon, hydrogen, oxygen, nitrogen,
and phosphorous
Polymers from monomers called nucleotides
Nucleotide has 5-carbon sugar, phosphate
group, and a nitrogenous baase
RNA – ribose sugar; DNA – deoxyribose sugar
– Store genetic information
Proteins
Contain carbon, nitrogen, hydrogen, and
oxygen
 Monomer of protein (polymer) is amino
acid

– Have amino group (-NH2) at one end and a
carboxyl group (-COOH) at the other end

More than 20 different amino acids found
in nature
When two or more amino acids are bound,
still has amino group on one end and
carboxyl group on the other end
 Polypeptide chain has three or more
amino acids bound together
 Polypeptide bond forms as a condensation
reaction (rxn) joins the amino group of
one amino acid with the carboxyl group of
the next in line  H2O released

Peptides

Short polymers
Hypertonic
• Solution has higher solute concentration
than the cell
• Water will move from inside the cell to
outside the cell
• Figure 7-16 (pg. 186)
Hypotonic
• Solution has a lower solute concentration
than the cell
• Water moves into the cell
Isotonic
• Concentration of solutes is the same in
and out of the cell
Utilize Fig. 7-16
• A homeowner contracts a lawn company
to add fertilizer to the lawn in order to
make the grass grow better. This process
is normally done by spraying a mixture of
fertilizer and water onto the lawn
• What would happen if too much fertilizer
and too little water were sprayed onto the
lawn?
• Can you suggest what happened to the
cells of the grass?
• In that case, was the fertilizer-water
mixture hypotonic or hypertonic compared
to the grass cells?
Figure 7-15
• In the beaker on the left, which solution is
hypertonic and which is hypotonic?
– The solution on the left side of the membrane
is hypertonic and the solution on the right is
hypotonic
• In this model, to which material is the
membrane permeable, water or sugar?
– Water!! This makes the membrane selectively
permeable