Transcript What is diffusion?

Jeopardy
Diffusion Osmosis
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Organelles Membranes Transport Chemistry
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$100 Question: Diffusion
What is diffusion?
$100 Answer: Diffusion
The movement of molecules
from areas of higher concentration to
areas of lower concentration.
$200 Question: Diffusion
Does diffusion require energy?
What is meant by passive
transport?
$200 Answer: Diffusion
No. It occurs with no added energy.
Passive transport is transport that
does not require energy.
$300 Question: Diffusion
Why are cells small?
$300 Answer: Diffusion
Diffusion is a slow process.
Diffusion into larger cells would take
too long to transport materials in and
out of the cell.
$400 Question: Diffusion
Heat is simply molecules moving
quickly. Would increasing temperature
increase or decrease the rate of diffusion?
$400 Answer: Diffusion
Increasing temperature would
INCREASE the rate of diffusion.
Molecules move faster when heated!
$500 Question: Diffusion
Which cell would experience the higher rate of
diffusion of material into it: a chicken egg or an
ostrich egg?Which would have the larger surface
area to volume ratio?
CHICKEN EGG
OSTRICH EGG
$500 Answer: Diffusion
Diffusion would occur faster into
the chicken egg because of its smaller
size. It would have the larger
surface area to volume ratio.
$100 Question: Osmosis
What is osmosis?
$100 Answer: Osmosis
The diffusion of water across a
selectively permeable membrane.
$200 Question: Osmosis
Why shouldn’t you drink salt water?
$200 Answer: Osmosis
The salt dehydrates your cells
by pulling water from them. Salt
water is hypertonic to cells,
therefore water osmoses out of the
cell into the surrounding solution.
$300 Question: Osmosis
Which of the following is better for
animal cells: being in a hypotonic
solution; being in a hypertonic
solution; or being in an isotonic
solution?
$300 Answer: Osmosis
Being in an isotonic solution.
Both hypotonic and hypertonic
solutions lead to cell death for
animal cells.
$400 Question: Osmosis
What would happen if you put eggs
laid by a salamander (a frog relative)
in fresh water into salt water? Is this
a hypotonic, hypertonic, or isotonic
solution?
$400 Answer: Osmosis
The water in the eggs (which
are cells) would leave the eggs.
The eggs would shrivel and die.
This is a hypertonic situation.
$500 Question: Osmosis
Compare the effect of putting an
animal cell and a plant cell into a
hypotonic solution.
$500 Answer: Osmosis
Water moves into both cells. The
plant cell will swell, but won’t burst because
of the plant cell wall.
The animal cell will burst, because it does
not have a cell wall.
$100 Question: Organelles
Which organelle is responsible for housing
the DNA in eukaryotic cells?
$100 Answer: Organelles
The nucleus.
$200 Question: Organelles
What parts are found in ALL cells?
List at least THREE!
$200 Answer: Organelles
Cytoplasm, ribosomes, DNA,
cell membrane.
$300 Question: Organelles
If the cell needs to export a protein
produced in the rough endoplasmic
reticulum, what other organelles could that
protein travel through? Your answer should
trace the path of the protein from the ER out
of the cell.
$300 Answer: Organelles
The protein would likely travel through the
rough ER to the Golgi. It would be packaged
in a vesicle and sent through the cell membrane.
$400 Question: Organelles
A cell converts energy from food it eats into
energy that’s usable by the cell using an
organelle. What kind of cell is this likely to
be? How do you know?
$400 Answer: Organelles
The cell could be any eukaryotic heterotroph
Including an animal cell, fungal cell or “protist”
cell. It’s a eukaryote because it has membranebound organelles (in this case, mitochondria).
It’s a heterotroph because it obtains food from
outside sources.
$500 Question: Organelles
Not all plant cells have chloroplasts, yet no
plant cells have to obtain food the way
animals do. Explain based on your
knowledge of cells and organelles.
$500 Answer: Organelles
Plant cells in leaves (and to some extent in
stems, tendrils, etc.) have chloroplasts that
can take sunlight energy and convert it to food
energy. That sugar is transported to other parts
of the plant, such as the bulb of an onion, and
stored or used.
$100 Question: Membranes
Define “selective permeability.”
$100 Answer: Membranes
Cells are choosy about what
enters into and exits from them.
$200 Question: Membranes
What structures in the cell membrane are
responsible for it being selectively permeable?
$200 Answer: Membranes
Phospholipids, proteins and carbohydrates
$300 Question: Membranes
Draw a phospholipid. Which part is
attracted to water? Which part is
repelled by water?
$300 Answer: Membranes
O
The phosphate head is
attracted to water. The fatty
acid tails are repelled by it.
$400 Question: Membranes
A colander (metal or plastic bowl
with a lot of holes in it used to drain
pasta) will let water out but not food.
Is this selective permeability? Why or
why not?
$400 Answer: Membranes
Yes, this is selective permeability,
because the colander is choosing
what passes through it.
$500 Question: Membranes
Mitochondria evolved from bacteria that
moved into eukaryotic cells and stayed.
What structures do you think are necessary
to transport materials into and out of
mitochondria? WHY?
$500 Answer: Membranes
Mitochondria are surrounded by a phospholipid
bilayer with proteins in it for active transport
and facilitated diffusion. Since mitochondria
evolved from bacteria, they have similar
structures to those found in prokaryotic cell
membranes. Those structures are homologous
to those found in cell membranes.
$100 Question: Transport
Does passive transport require
energy?
$100 Answer: Transport
No. It doesn’t need any additional
energy.
$200 Question: Transport
Name three types of active transport.
$200 Answer: Transport
Ion pumps; exocytosis; endocytosis.
$300 Question: Transport
What kinds of molecules can diffuse
easily into and out of cells? What
kinds of molecules cannot diffuse
easily into and out of cells?
$300 Answer: Transport
Small nonpolar molecules (oxygen, CO2)
can diffuse into and out of cells easily.
Large polar molecules (starch, glucose,
proteins) cannot diffuse into and out of
cells easily.
$400 Question: Transport
Endocytosis requires energy to bring
food particles and liquids into the cell.
This is an example of:
a. Passive Transport
b. Osmosis
c. Diffusion
d. Active Transport
$400 Answer: Transport
D. Active Transport.
$500 Question: Transport
Compare active transport and
facilitated diffusion.
$500 Answer: Transport
Facilitated diffusion does not use energy. Active
transport does. Both can use transmembrane
proteins (proteins that go through the cell
membrane). Facilitated diffusion transports
substances from areas of high concentration to
areas of low concentration. Active transport
transports substances from areas of low
concentration to areas of high concentration.
$100 Question: Chemistry
A sodium atom donates an electron to
a chlorine atom. The sodium becomes
positively charged and the chlorine negatively
charged. What kind of bond do they form?
$100 Answer: Chemistry
An ionic bond.
$200 Question: Chemistry
A molecule is made of an oxygen atom and
two hydrogen atoms that share electrons
unequally. What kind of bond holds this
molecule together?
$200 Answer: Chemistry
Polar covalent bond because electrons
are shared unequally between molecules.
$300 Question: Chemistry
Draw and label a hydrogen bond between
molecules of water. Label each element in
the molecules of water and the charges on
each.
$300 Answer: Chemistry
BACK.
O
H
H
$400 Question: Chemistry
How does hydrogen bonding contribute to one
property of water? Describe one property of
Water, how hydrogen bonding contributes to it,
and give an example of that property found in
nature.
$400 Answer: Chemistry
Water sticks to iteself and other polar objects
through hydrogen bonding.
Cohesion: Water sticks to itself to form the
surface of lakes/oceans/etc.
Adhesion: Water sticks to the tubes in plants.
Surface Tension: Insects/lizards can walk/run on
water.
Capillary action: Water climbs up tubes in plants.
$500 Question: Chemistry
Boiling point is the temperature at which
A liquid becomes a gas. Water has a much
higher boiling point than benzene, a nonpolar
molecule. Why? Your answer should relate
to polar and nonpolar covalent bonds!
$500 Answer: Chemistry
Hydrogen bonds (caused by polar covalent
bonds) cause water molecules to stick together.
Since water molecules stick together, it takes
energy to pull them apart, therefore giving
water a higher boiling point. Benzene, which
has nonpolar covalent bonds, doesn’t form
hydrogen bonds, doesn’t stick together and
therefore boils at low temperatures.