Download Standard 2

Standard 2
Addison
&
Claire
Homeostasis
• Homeostasis- The ability of an organism or cell to
maintain internal balance and stability by adjusting to
physiological processes.
• Homeo= equal
• Plant and animals use this process.
• Example: If a plant does not have enough water, then it
wilts. When the plant gets water, it is balanced again.
ACTIVE Transport
• Active Transport- The movement of a substance across a biological
membrane against its concentration or electrochemical gradient with
the help of energy input and specific transport proteins.
• In other words, it is the process of moving molecules and other
substances across membranes.
• The cell actively moves to get food or water.
• It involves energy.
• Active transport is used in animal cells.
• Endocytosis and exocytosis are types of active transport.
Endocytosis
• Endocytosis- The
cellular uptake of
macromolecules and
particulate substances
by localized regions of
the cell membrane that
surround the substance
and pinch off to form an
intracellular vesicle
• Endo= within
• The cell takes in
something by
swallowing the material
with its cell membrane.
Exocytosis
• Exocytosis- The cellular
secretion of
macromolecules by the
fusion of vesicles with the
cell membrane.
• Exo= external
• Something leaves the cell.
• It is the opposite of
endocytosis.
PASSIVE Transport
• Passive Transport- The diffusion of a substance across a
biological membrane.
• In other words, the cell just sits and things go in and out
by themselves.
• It does not use energy.
• Diffusion and osmosis are types of passive transport.
Diffusion
• Diffusion- The spontaneous tendency of a
substance to move down its concentration
gradient
• In other words, particles move from an area of
higher concentration to an area of lower
concentration.
• The result is a slow mixing of the material. For
example, when food coloring is dropped into a
bowl of water, the coloring eventually spreads
evenly throughout the water.
Osmosis
• Osmosis- The diffusion of water across a
selectively permeable membrane.
• The amount of water inside and outside
the cell determines whether it is isotonic,
hypotonic, or hypertonic.
• ISOTONIC- The solutions inside and
outside the cell are equal.
• HYPOTONIC- The solution outside of the
cell is more concentrated than the solution
inside of the cell.
• HYPERTONIC- The solution inside of the
cell is more concentrated than the solution
outside of the cell.
#1. Molecules move from areas of high
concentration to areas of low
concentration through the process of
A. osmosis
B. diffusion
C. passive transport
D. active transport
The answer is…
• B- Diffusion
• Diffusion causes molecules to go
from high concentration to low
concentration.
#2. Which statement describes the amount of
water in a cell after it has been placed in a
sugar solution?
A. It is larger because sugar entered the cell by
diffusion.
B. It is larger because water entered the cell by
osmosis.
C. It is smaller because sugar left the cell by
diffusion.
D. It is smaller because water left the cell by
osmosis.
The answer is…
• D- It is smaller because water left the
cell by osmosis.
• Since more water is inside the cell,
water goes from an area of high
concentration, the cell, to an area of
low concentration, the sugar solution.
#3.Is this an example of active transport or
passive transport?
The answer is…
• Active Transport
• The organism is actively moving to
get a particle.
#4. Which statement describes the cellular conditions in
which passive transport would occur?
A.
B.
C.
D.
Energy is used to move molecules from an area of low
concentration to an area of high concentration.
Energy is used to move molecules from an area of
high concentration to an area of low concentration.
There is a concentration gradient across a semipermeable membrane where molecules move from an
area of low concentration to an area of high
concentration.
Energy is not used to move molecules across a semipermeable membrane from an area of high
concentration to an area of low concentration.
The answer is…
•D- Energy is not used to move molecules across a
semi-permeable membrane from an area of high
concentration to an area of low concentration.
•In passive transport, energy is not used. Also,
molecules are moved to an area of lower
concentration.
#5. Study the diagram below.
Which arrow shows the direction the solute molecules
would move to achieve homeostasis?
A.
B.
C.
D.
The answer is…
•B
• The molecules would move to the
left to achieve balance.
#6. Study the diagram below.
A potato slice is placed in distilled water in Breaker 1. A
similar potato slice is placed in salt water in Breaker 2.
Which statement correctly explains the movement of water
across cell membranes in one of the potato slices?
A.
B.
C.
D.
Water will move out of the potato cells in Breaker 1 because the solution
is more concentrated.
Water will move into the potato slices in Breaker 1 because the solution is
more concentrated.
Water will move out of the potato cells in Beaker 2 because the solution
has less water.
Water will move into the potato cells in Beaker 2 because the solution is
more concentrated.
The answer is…
•C- Water will move out of the potato cells in Beaker
2 because the solution has less water.
•Water moves out to dilute the salt water solution.
The salt water solution has less water, so the water
in the potato cell moves out to a lower
concentration.
#7. Study the figure below.
If the membrane shown is permeable to molecules of X but
impermeable to molecules of Y, what will be the result of diffusion
over time?
A.
B.
C.
D.
Molecules of X on each side of the membrane will become equal
in concentration.
Molecules of Y on each side of the membrane will become equal
in concentration.
Molecules of X will increase in concentration on the right side.
Molecules of Y will increase in concentration on the right side.
The answer is…
• A- Molecules of X on each side of the
membrane will become equal in
concentration.
• Because the membrane is permeable to X
molecules, they will diffuse from an area of
higher concentration to an area of lower
concentration.
#8. Study the information below.
A.
B.
C.
D.
Two cells are separated
by semi-permeable
membranes. The starch
molecules cannot pass
through the
membranes, but the salt
molecules can pass
through the
membranes. Which
statement describes the
process for
achieving homeostasis
between the cells?
Salt will move from 2 to 1 by diffusion.
Salt will move from 1 to 2 by diffusion.
Salt will move from 2 to 1 by osmosis.
Salt will move from 1 to 2 by osmosis.
The answer is…
• B- Salt will move from 1 to 2 by
diffusion.
• Since more salt molecules are
present on part 1 of the cell,
they will move to part 2 of the
cell through diffusion.
#9. Which choice is NOT an example of
homeostasis?
A.
B.
C.
D.
Shivering
Sweating
Growing
Breathing
The answer is…
• C- Growing.
• Shivering, sweating, and breathing are
all examples of homeostasis. Shivering
helps maintain body heat, sweating
cools the body down, and breathing
regulates the balance of carbon dioxide
and oxygen; however growing is not an
example of homeostasis.
#10. True or false:
Passive transport has do to do with the
diffusion of particles.
The answer is…
•True
•Particles are diffused across a
membrane.
#11. True or False:
Osmosis is the transfer of air particles
around the cell.
The answer is…
• False
• Osmosis is the diffusion of water
across a permeable membrane.
#12. What is the difference between
exocytosis and endocytosis?
The answer is…
• Exocytosis- a substance leaves the cell
• Endocytosis- a substance enters the
cell
#13. Does passive transport use energy?
The answer is…
• No
• Things just pass in and out of the
membrane in passive transport.
#14. Is this an example of an isotonic,
hypotonic, or hypertonic solution.
The answer is…
• Hypotonic
• The solution on the outside is
more concentrated.
#15. Endocytosis and exocytosis are
examples of
A.
B.
C.
D.
Passive Transport
Diffusion
Active Transport
Osmosis
The answer is…
• C- Active Transport
• Endocytosis and exocytosis use
energy, which means they are
active.