Transcript Cell Energy

Marking Period 2
Quarterly Exam Review
2014-2015
Cell Transport, Homeostasis,
Photosynthesis, Cellular Respiration,
Mitosis
Cell Membrane (aka Plasma Membrane)
1. Label the following parts of the cell
membrane pictured below: hydrophilic heads,
hydrophobic tails, membrane protein channels,
cholesterol, and carbohydrate chains.
Carbohydrate Chain
Hydrophilic head
(polar)
Hydrophobic
tails (nonpolar)
Membrane
Transport Protein
Cell Membrane (aka Plasma Membrane)
2. Explain why the heads and tails either
face the watery environments or repel it.
How does this help the cell?
O The heads are polar and are attracted to
water so they face it (outside and in)
O The tails are nonpolar and repel water so
they turn against it.
O THIS ALLOWS THE CELL MEMBRANE TO BE
SEMI-PERMEABLE, ALLOWING THE PASSAGE
OF MATERIALS IN AND OUT OF THE CELL.
Cell Membrane (aka Plasma Membrane)
3. Why do we call the cell membrane a fluid
mosaic model?
O The cell membrane is fluid-like because the
parts that are in it move in a way that looks
like a fluid.
O It is a mosaic because it has many pieces to
it, like a mosaic tile piece of art.
Cell Membrane (aka Plasma Membrane)
O Cell Membranes Rap:
O https://www.youtube.com/watch?v=Pfu1DE
9PK2w
Cell Transport
1. How does passive transport relate to the
concentration gradient? How does the
concentration gradient affect how molecules
move?
O Passive transport moves DOWN the
concentration gradient.
O This means that molecules will move from
the side of the membrane where there are a
lot of molecules to the side of the
membrane where there are less molecules
O High  Low
Cell Transport
2. What is diffusion? Give an example of something
that could easily diffuse into or out of a cell. Show a
simple picture of diffusion of food coloring in a beaker
of water.
O Diffusion = movement of molecules from high to low
concentration
O Example: Oxygen or Carbon Dioxide
Cell Transport
3. What is osmosis? Give 3 examples (draw/explain) of what would
happen to a cell if it were placed into an isotonic, hypotonic, or a
hypertonic environment. Why would osmosis cause these things to
happen?
Osmosis = diffusion of water (movement of a solvent from high to
low concentration
Hypertonic: Water moves out of the cell and the
contents inside the cell shrink because there was more
water in the cell than its surrounding environment.
Isotonic: Water moves equally in and out because the
solute concentration is equal inside the cell and outside
the cell.
Hypotonic: Water moves into the cell and the cell
expands because there was more water in the surrounding
environment than there was inside the cell.
Cell Transport
4. What is facilitated diffusion? Give an
example of something that could enter a cell
this way. How is facilitated diffusion
different from regular diffusion?
O Movement of molecules from high to low
concentration with the help of a transport
protein
O Glucose enters the cell this way
O Different than regular/simple diffusion
because it uses a carrier protein while
simple diffusion does not use a protein
Cell Transport
Diffusion vs. Facilitated Diffusion
O Facilitated Diffusion Video:
O https://www.youtube.com/watch?v=b0-
0tKHfzNE
Cell Transport
5. What is active transport? How does active
transport relate to the concentration gradient?
O Movement of molecules from LOW to HIGH
concentration using energy
O Goes UP or AGAINST the concentration gradient
O (Think about trying to paddle a boat upstream
against the current – you would have to use a lot
of energy to do this)
Cell Transport
6. Give three examples of active transport
and explain each.
1. Endocytosis: plasma membrane wraps around
particles and brings them into a cell, creating a
vesicle (Phagocytosis = solids; Pinocytosis = liquids)
2. Exocytosis: vesicle fuses with the plasma membrane
and releases substances outside of the cell
3. Sodium-Potassium Pump: ATP energy is used to
change the shape of a protein in the membrane to
exchange three sodium ions outside of the cell to
bring two potassium ions into the cell
Cell Transport
7. What are three differences between active
and passive transport?
Passive Transport
Active Transport
No ATP energy needed
Uses ATP energy
High to Low concentration
Low to High concentration
Down the concentration
gradient
Against/Up the concentration
gradient
Cell Transport
8. Where are membrane protein receptors
found and how do they aid in cell transport?
O They are found in the cell membrane.
O A receptor is a protein that detects a signal
molecule and preforms an action in
response. They move needed molecules into
a cell.
Cell Transport
9. What is homeostasis? How do cells maintain
homeostasis? How can our bodies maintain
homeostasis?
O Homeostasis is when an organism is able to maintain
a stable internal environment even when external
conditions change.
O Cells maintain homeostasis by making changes
(example – they use biological buffers to regulate pH
and keep it stable)
O Bodies maintain homeostasis by doing things like
sweating to cool the body or shivering to warm the
body up (muscle cells contract to make us move and
produce heat) - called thermoregulation
Cell Energy
1. What is the purpose of photosynthesis? What
organelle is responsible for photosynthesis?
O The purpose of photosynthesis is for autotrophic
organisms to transform light energy into chemical
energy (glucose). (Make food)
O The organelle responsible for photosynthesis is the
chloroplast.
Cell Energy
2. What are the energy changes/transformations that
happen in photosynthesis? Explain the difference
between the light dependent reaction and light
independent reaction.
O Light to Chemical Energy (glucose)
O The light dependent reaction takes place in the
thylakoid and uses the light to split water (release
oxygen) and make ATP and NADPH.
O The light independent reaction takes place in the
stroma and uses carbon dioxide from the
atmosphere and the ATP and NADPH from the
previous reaction to make chemical energy (glucose).
Cell Energy
3. What is the purpose of cellular respiration?
What organelle is responsible for producing the
energy in cellular respiration?
O The purpose of cellular respiration is to
change chemical energy (glucose) into
useable energy (ATP) for cellular
work/activities.
O The mitochondria is responsible for cellular
respiration.
Cell Energy
4. What are the energy
changes/transformations that happen in
cellular respiration?
O Chemical Energy (glucose) to Chemical
Energy (ATP).
Cell Energy
5. What is ATP used for in living things? Draw a
diagram showing how energy is released from an ATP
molecule when we “use” energy.
O ATP is adenosine triphosphate, it is an energy carrier
in living things.
O It is used by cells so they can do their “work” (make
proteins, copy DNA, etc.)
Cell Energy
6. Draw a diagram showing how energy is
stored when ADP is converted into ATP.
Cell Energy
7. In terms of cellular respiration, explain
why we need to eat and why we need to
breathe.
O Eat: get glucose (since we cannot make it
through photosynthesis)
O Breathe: in – oxygen
out – carbon dioxide and water
Cell Energy
8. Explain why plants do not need to eat.
O Plants are able to make their own source of
glucose to use in cellular respiration since
they are able to perform photosynthesis
Cell Energy
9. What are the inputs of photosynthesis?
The outputs?
Inputs
Outputs
Cell Energy
10. What are the inputs of cellular
respiration? The outputs?
Inputs
Outputs
Cell Energy
11. Refer to your previous two answers: How
do photosynthesis and cellular respiration
form a cycle?
Cell Energy
Extra Question: What is similar about the
energy transfers in photosynthesis and
cellular respiration?
O Both processes store energy in chemical
bonds.
Mitosis
O Big Bang Theory Mitosis Clip:
O https://www.youtube.com/watch?v=HV5kPi
DYC3M
Mitosis
1. What does G1 stand for, what happens to a
cell in G1?
O Gap One
O The cell grows, replicates its organelles.
Mitosis
2. What does S stand for, what happens to a
cell in S?
O Synthesis
O DNA is replicated (copied)
Mitosis
3. What does G2 stand for, what happens to
a cell in G2?
O Gap Two
O The cell grows more and goes through a
final checkpoint.
Mitosis
4. What three parts make up Interphase?
O Gap One
O Synthesis
O Gap Two
O Gap Zero sometimes occurs between Gap 1
and S phase – it is a temporary or
permanent resting stage
Mitosis
5. What does M stand for, what happens to a
cell in M? Describe what happens in PMAT.
O M stands for Mitosis
O The contents of the nucleus divide in 4 phases
O
O
O
O
(prophase, metaphase, anaphase, telophase).
P = Prophase: chromosomes appear, nuclear
membrane disappears
M = Metaphase: chromosomes line up in the
middle of the cell
A = Anaphase: sister chromatids are pulled
apart
T = Telophase: two nuclear membranes
reappear; DNA uncoils back into chromatin
Mitosis
O Mitosis Animation:
O https://www.youtube.com/watch?v=Cg4ASx
SKH2o
Mitosis
6. Describe what happens in mitosis in one
sentence.
O DNA is copied once, the cell divides once,
and two genetically identical daughter cells
are made.
Mitosis
7. What is the second part of the M phase
before a cell goes back into Interphase?
O Cytokinesis (cytoplasm splits)
Mitosis
8. Why are there 2 genetically identical cells
drawn after cytokinesis?
O Mitosis produces 2 genetically identical
cells.
Mitosis
9. If the original somatic cell had 36
chromosomes in it, how many
chromosomes would be in the resulting
somatic cells? Draw a picture to show this.
O 36 in each new cell (mitosis makes identical
cells)
36
36
36