Transcript Ch. 5 Review

Ch. 5 Review
5.1 Passive Transport
Differentiate the terms solute and solvent.
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Solute = substance being dissolved
Solvent = substance doing the dissolving
What is the solvent inside and outside of the
cell?
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Water
What are the four components of the cell
membrane?
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Phospholipids
Carbs
Proteins – both integral and peripheral
Steroids (cholesterol)
What does selectively permeable or semipermeable mean?
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Only certain things can pass through
What are the two main types of transport?
What’s the difference between the two?
Passive transport
Active transport
•No ATP needed
•ATP needed
•Movement of particles from high to low
concentration
•Movement of particles from low to high
concentration
List the four types of passive transport.
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Simple diffusion
Osmosis
Facilitated diffusion
Diffusion through ion channels
Define diffusion. Why does it occur?
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Movement of particles from high conc. to low
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Occurs naturally due to kinetic energy of particles
Give an example of diffusion.
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Food coloring in water
Perfume/cologne
Loss of helium from a balloon
Smoke
Oxygen, carbon dioxide, and other small nonpolar
molecules across the cell membrane
What is equilibrium?
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Particles are spread evenly throughout a space
Do the particles stop moving in equilibrium?
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No!
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Why not?
They have kinetic energy!
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What is osmosis?
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Movement of water from high to low conc. through a
membrane
Define hypertonic, hypotonic, and isotonic.
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Hypertonic = high solute
Hypotonic = low solute
Isotonic = same solute
In which of those solutions are the particles
in equilibrium?
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Isotonic
Which way does water flow when cells are in
a hypotonic solution?
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In
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What happens to animal cells?
Cytolysis
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What happens to plant cells?
Turgor pressure
What is cytolysis?
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Cell bursting
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Why don’t plant cells experience cytolysis?
They have cell walls
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What is turgor pressure?
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Pressure of membrane pushing against the cell wall
Which way does water flow when cells are in
a hypertonic solution?
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Out
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What happens to animal cells?
Crenation
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What happens to plant cells?
Plasmolysis
What is crenation?
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Cell shrinking/shriveling
What is plamolysis?
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Cell membrane pulls away from cell wall
If you are stranded at sea, why shouldn’t
you drink the ocean water?
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It’s too salty! You would be putting your cells in a
hypertonic environment which would cause them to lose
water!!
What is facilitated diffusion?
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Assisted diffusion
Movement of particles from high conc. to low through a
transport protein called a carrier protein
Do carrier proteins transport lots of different
types of molecules or one type of molecule?
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One type… they are specific!
List the steps of facilitated diffusion.
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Carrier protein binds to molecule
Carrier protein changes shape
Molecule moves through
Molecule released on other side; carrier protein returns
to original shape and is reusable
What types of molecules move by facilitated
diffusion?
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Glucose
Small polar molecules
What is diffusion through ion channels?
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Movement of ions from high conc. to low through carrier
proteins called ion channels or channel proteins
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Ion channels are also specific – they only move one type
of ion
What is the everyday word for an ion?
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electrolyte
Why can’t ions move through the cell
membrane on their own?
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They are charged – repelled by nonpolar interior of cell
membrane
Some ion channels open and close. What
are they called?
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Gated channels
What controls the opening/closing of gated
ion channels?
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Cell membrane stretching
Electrical signals
Chemical signals
What are some common ions?
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sodium (Na+)
potassium (K+)
calcium (Ca2+)
magnesium (Mg+)
chlorine (Cl-)
phosphate (PO4-)
bicarbonate (HCO3-)
Why are ions important?
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Heartbeat and nerve function
Fluid balance
Oxygen delivery
Acid-base balance
5.2 Active transport
What’s the difference between active and
passive transport?
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Active transport moves substances against the gradient
Active transport requires ATP!!
List the types of active transport
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Protein pumps
Endocytosis
Exocytosis
What is a protein pump?
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Transport protein that moves molecules from low to high
conc. ; requires energy
What are the basic steps of how protein
pumps work?
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Protein binds to molecule
Protein changes shape; this requires ATP!
Molecule moves through protein and is released on the
opposite side
Protein returns to original shape and is reusable
Give an example of a protein pump.
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Sodium-potassium pump
Cells must maintain higher sodium _______
and higher potassium _________ the cell.
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Outside
Inside
Sodium and potassium always move in a
________ ratio.
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3:2
Describe how the sodium-potassium pump
works.
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3 sodiums bind to the pump on the inside of the cell
Protein splits a phosphate from ATP and releases energy; the
free phosphate binds to the pump causing it to change shape
3 sodiums move out
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2 potassiums bind to pump on outside of cell
Phosphate is released from pump causing it to change shape
Potassiums move in
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Protein returns to original shape and is reusable
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Define endocytosis.
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Talking bulky materials into a cell
What are the two types of endocytosis?
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Pinocytosis
Phagocytosis
What’s the difference between the two?
Pinocytosis – fluids, cell “drinking”
Phagocytosis – solids, cell “eating”
How does endocytosis work?
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Cell membrane folds inward around material to be
ingested
Membrane pinches off inside of cell forming a vesicle
Vesicle fuses with a lysosome to digest materials
Define exocytosis.
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Forcing material out of the cell in bulk
How does it work?
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Vesicle containing material fuses with the cell membrane
releasing contents outside
The cell membrane changes shape… this
requires ___________.
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Energy
Give three examples of materials released
from a cell by exocytosis.
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Hormones
Proteins
Wastes