Transcript MID YEAR BIOLOGY REVIEW

MID YEAR BIOLOGY REVIEW
Excerpts from powerpoints used in class
(with one exception) during the first
semester. Review
Scientific Method
• Scientific Method – way in
which scientists gather
information and answer
questions.
• The goal of science is to
investigate and understand
the natural world, explain
events, and use those
explanations to make useful
predictions.
• There are generally 7 steps
to the scientific method.
– This is a good flow chart of the
scientific method.
– Note: There are many versions
of the steps of the scientific
method, but they are
essentially all the same!
1. Stating the problem
2. Gathering information on the problem
• 1. Stating the problem is
something that you want to find
out.
– Example: Why did 10 people get
sick with E.coli at Saturday’s
picnic?
• 2. Gathering information on the
problem? You must first
Observe and gather facts!
– Observation: Everyone who got
sick with E. coli ate the chicken,
potato salad and/or ate ice cream
within 72 hours.
– Inference: What does this
suggest?
Observation Versus Inference
• There are two types of data scientists gather:
quantitative and qualitative.
• When scientists gather information, they begin with
observations or the process of recording information
in a careful or orderly way. This is called Quantitative
data.
• Scientists also use data to make inferences. This is
a logical interpretation based upon prior knowledge
or experiences. This is called Qualitative data.
Let’s start out easy and then test your skills with a
few observation versus inference games!
3. Forming a Hypothesis
• Hypothesis – proposed
solution or educated guess to
the problem.
• They must be proposed in
such a way that they can be
tested. (or testable.)
• There can be multiple
hypotheses or many solutions
to a scientific problem!
– Example: Remember the bad
picnic?
• 1. The chicken was bad (infected
with E.coli) and made people sick.
• 2. The potato salad was bad
(infected with E.coli) and made
The Suspects!
4. Performing experiments to
test the Hypothesis
• We must test the hypothesis to determine whether or not it
is correct or explains what is going on in our problem.
• Testing is done through experiments.
– Example: Compare the items that made people sick by growing
samples of bacteria (E.coli) on culture plates resistant to other types
of pathogen growth using sterile techniques.
– Why is it important to have specific media?
1
3
2
4
5
4. Experiment: Controls
• Controls – There are two types of controls
in every experiment used as a basis of
comparison.
– Positive Control: Your anticipated outcome of the
experiment. This control ensures that your
experiment is working properly and/or there are
not any outside factors influencing the outcome
of your experiment.
• Example: A pure sample of E.coli that made everyone
sick from the picnic.
• Outcome: A sample of E.coli will grow on this plate.
1
E.coli
– Negative Control: Contains no variables and
should have no effect or outcome in your
experiment. This control ensures that no
contamination has occurred in your experiment.
• Example: No sample of any food item added to the petri
dish.
• Outcome: Nothing should grow on this plate.
2
nothing
4. Experiment: Variables
• In designing an experiment, only one variable is tested at a
time with your positive and negative controls.
• Variable – the factor being tested
– Independent Variable – Factor you can manipulate
– Dependent Variable – Factor that responds to the
manipulation and can be measured.
• Example: Samples of the three food items from the picnic.
3
Chicken
4
Potato
salad
5
Ice
cream
5. Recording and Analyzing
Data
• A) Data are Recorded
observations and
measurements.
– Data is usually shown in
a table or chart.
• B) Then data is made
into a graph to show
trends.
– Makes information
easier to see!
– We’ll conduct a graphing
experiment later…
6.Stating a conclusion
7.Repeating the experiment
• 6. Once you have looked at your data, you can draw
conclusions.
– Example: Which plate showed growth? What food was
the culprit? What would you report based upon your
outcome?
• Other Outcomes/Conclusions:
– What if nothing was wrong with the food at all? How would
you revise your hypothesis and conduct another
experiment?
– What if there was no growth on plate 1?
– What is there was growth on plate 2?
• 7. In order to ensure your data is accurate AND to that your
hypothesis accurately explains what is scientifically going on,
experiments will be constantly repeated.
– Why is this important?
Safety Goggles
• Used for Eye protection.
• The most common used
safety item in the biology
laboratory.
• Use when there are
Chemicals, Flames or
Heating.
• They give you protection
against flying objects or
toxic substances.
• If your eyes come into
contact with a substance,
use the eye wash
Poison
• Do not let it on your skin or
inhale its vapor.
• Wash your hands after
handling.
• Can cause death if eaten or
drunk.
• Let your teacher know
immediately if you come
into direct contact.
• Always hold test tubes or
flasks away from your
nose and face and waft
odors towards you.
Fire Hazard
• Wear safety
goggles with fire
hazards.
• Tie back loose hair
and clothing.
• Ask your teacher
about lighting and
extinguishing fires
during a lab.
Physical Safety
• This activity
involves physical
activity.
• Use caution to
avoid injuring
yourself and others.
• Follow all
instructions from
your teacher.
• Alert your teacher if
there is any reason
you should not
participate in this
Glassware Hazard
• Glassware is
present and can
cause injury.
• Glassware should
be cleaned with
each use to avoid
contamination.
• Alert your teacher if
there is any broken
glassware.
• Broken glass goes
in a special “sharps”
container, not in the
Sharp Object
• Scissors, scalpels, razor
blades, pins, and knives
are sharp so use care.
• Always direct sharp
edges and points away
from yourself and others.
• If you are cut or
bleeding, let your
teacher know
immediately.
• Use only as directed.
• Use an oven mitt or gloves
when handling hot materials.
• Use clamps or tongs to hold
hot objects.
• Always heat objects in a test
tube away from you and
others.
• Hot plates, hot water and
hot glassware can cause
burns.
• Glassware looks the same
when hot or cold, so use
care when heating any type
of glass.
• Rapid changes in glass
temperature can cause it to
expand, crack and/or
explode!
• Plastic tools should never be
heated on a hot plate!
– They will melt!
Heat Hazard
Corrosive Chemical
• Indicates an acid or
other corrosive
chemical.
• Wear gloves at all
times and safety
goggles!
• Avoid getting in skin
or eyes.
• Do not inhale
vapors.
• Wash your hands
after lab activity.
Electrical Hazard
• Avoid electric shock.
• Never use electrical
equipment around water
or when your hands are
wet.
• Be sure cords are
untangled and
unplugged when not in
use.
Animal Safety
• Treat live animals
with care.
• Be careful when
dissecting
preserved animals.
– Wear safety
goggles!
– Wear latex gloves!
• Wash your hands
after lab.
Why Graph?
• When performing an experiment, a
scientist must be able to record an
immense amount of data and process
that data into useful information.
• This is done by converting raw data into
charts or tables.
• Then, the data must be graphed such
that it can be interpreted by the public.
• Graphs are visual representations of
data.
Part 1: Tables and Charts
• Tables and charts
are created for
organizing data
from raw data.
• The chart should
show how a trend
occurs over several
occurrences,
(months, trials,
categories, etc) or
over time.
• Once data is
organized, it can be
Part 2: Graphing Data
A) Pie Graphs
• Pie graphs are
useful in showing
percentages.
• Displays how
different categories
are represented
within a topic area.
– Sample: How
many land does
Asia take up in the
world?
Part 2: Graphing Data B) Bar Graphs
• A bar graph is a way of showing
relationships between variables,
typically items that being compared.
• It contains an x and y axis.
– These are 2 lines that meet at a
right angle.
• It uses a series of columns to display
data.
– Example, how does the number of
farms in 1910 compare with 1990?
• Notice:
– The x and y axis are always labeled.
– The graph has a title.
– The bars are vertical.
– The numbers on the Y axis are in
sequence for an accurate
comparison.
Part 2: Graphing Data
C) Line Graphs
• A line graph shows the best relationship
between 2 variables.
• Along the x-axis (horizontal) is the
manipulated or independent variable.
• Along the y-axis (vertical) is the
responding or dependent variable.
• Has one or more lines connecting a
series of points.
• Notice:
– Time is on the x-axis (independent
variable)
– Distance is on the y-axis (dependent
variable)
– Distance and time are in sequence.
Constructing a graph
• Decide which variable to place along the x and y
axis.
• Decide on a scale for your graph.
– Must be as large as possible within the limits of the paper
and still include the largest item of data.
– Select your scale with ease of locating points, multiples
of 1, 2, 5, or 10 are easiest.
• Your Turn! Flip on the back of your notes and let’s
conduct a graphing experiment!
Organic Polymers
• Polymers – macromolecules made of
repeating units called monomers.
• Four types: carbohydrates, lipids, nucleic
acids, proteins.
Monomers
Polymer
2-3
Carbohydrates
• Carbohydrates – compounds made of
carbon, hydrogen, and oxygen in a ratio
usually 1 : 2 : 1.
– Energy source!!!
– Ex: sugars, starches, glycogen, cellulose
– Monosaccharides (monomer) (glucose)
– Polysaccharides (polymer) (starch)
2-3
Carbohydrates
Lipids
• Lipids – made of mostly carbon and
hydrogen atoms.
– Fats, oils, waxes
– Three fatty acids and a glycerol
– Store energy, make membranes, waterproof
2-3
Lipids
Nucleic acids
• Nucleic acids – contain hydrogen, oxygen,
carbon, nitrogen, and phosphorus.
– Carry genetic information
– Monomers = Nucleotides
– Ex: DNA and RNA
2-3
Proteins
• Proteins – contain carbon, hydrogen,
oxygen, and nitrogen.
– Form bones/muscles, transport substances,
fight disease, control reactions, regulate cell
processes.
2-3
Proteins
–Monomers = amino acids
–Peptide bond – bond
between amino acids.
What are Enzymes?
• Enzymes are proteins which act as
biological catalysts.
• Their subunits are amino acids.
• Enzymes are used by cells to trigger and
control chemical reactions.
• Without enzymes, several reactions in
cells would never occur or happen to
slowly to be useful.
What is activation energy?
• Activation
energy is the
amount of
energy needed
to start a
chemical
reaction.
• Enzymes
speed up
chemical
reactions by
lowering
their
activation
energy.
What is a substrate?
• Enzymes bind to molecules called
substrates.
• These substrates are the reactants that
are catalyzed by the enzyme.
Lock and Key Hypothesis
• Each protein has a
specific shape, therefore
enzymes bind to
substrates based on
shape.
• The site on the enzyme
where the substrates bind
is called the active site.
• Enzymes bind to the
substrates based on their
complementary shape..
• The fit is so exact that the
active site and substrates
are compared to a “lock
and key”.
How are enzymes affected by the
reactions?
• Enzymes are
NOT changed
by the reactions
they catalyze,
therefore they
are reusable!
Induce Fit Hypothesis
• Enzymes can change shape
slightly to fit the substrate a little
better (like a hand in glove).
How can enzymes be affected?
• Enzymes can be affected by temperature and
pH.
• Temperatures outside the correct range can
cause enzymes to break down or change shape.
• This break down is called denaturation.
• Therefore, enzymes in our body work best at
37°C (98.6°F) and at a pH between 6.5 to 7.5.
Ex: Catalase is an enzyme that breaks down
hydrogen peroxide.
– H2O2 → H2O + O2 (gas)
– A raw potato in H2O2 gives off O2. The boiled potato
give no bubbles because the enzyme has changed due
to heat.
Enzymes can turn On & Off
• Most cells contain proteins that turn
enzymes on or off during critical stages of
development.
Diffusion
• Diffusion – net
movement of particles
from an area of higher
concentration to an area
of lower concentration
• Caused by random
movement
• Is a slow process
because it relies on the
random molecular motion
of atoms
Rate of Diffusion
• Three key factors affect
the rate of diffusion:
– 1. Concentration.
The most important
factor. The more the
concentrated the
substances, the faster
diffusion occurs.
– 2. Temperature.
Increased temperature
can speed diffusion
because of more rapid
molecular movement
– 3. Pressure.
Increased pressure will
accelerate molecular
movement and speed
up diffusion.
The Result of Diffusion
• Eventually, the two
different concentrations
(the concentration
gradient) will be
distributed evenly.
– This is called dynamic
equilibrium.
• Diffusion is one of the
methods that cells move
substances in and out
of the cell
Osmosis
• Osmosis – the diffusion
of water across a
selectively permeable
membrane
• Regulating water is a
very important factor in
maintaining
homeostasis in the cell.
What
controls
Osmosis?
• If two solutions are separated by a selectively permeable
membrane…
– Water will flow to the side of the membrane where the water
concentration is lower
– However, the substances in the water are prevented from moving and
keep their original concentrations.
• Therefore, osmosis is controlled by a concentration gradient,
that is an unequal distribution of particles across a membrane.
– Movement from a low solute concentration (high water potential) to a
solution with high solute concentration (low water potential)
Your Turn!
Which way will the water go?
On your sheet, record what will
happen to the red blood cells in
each of these three cases:
Red Blood Cells (5% salt) in
40% Salt Solution
Red Blood Cells (5% salt) in
5% Salt Solution
Red Blood Cells (5% salt) in
Pure Water (0% salt solution)
Check your work!
How Osmosis affects cells:
Isotonic Solution
• All cells are subject to
osmosis since they are
surrounded by water.
• In an Isotonic Solution,
the concentration of
dissolved substances in
the solution is the same
as the concentration of
dissolved substances
inside the cell.
• There is equal flow and
water goes in both
directions.
• Therefore, cells retain
their original shape since
the water concentrations
are equal.
How Osmosis affects cells:
Hypotonic Solution
• In an Hypotonic Solution,
the concentration of
dissolved substances in the
solution is lower than the
concentration of dissolved
substances inside the cell.
• Therefore, there is more
water outside the cell than
inside & water flows in!
– Animal cells may burst
– Plant cells become more
rigid…
• how does this explain the
misting machines in the
produce section of grocery
stores?
How Osmosis affects cells:
Hypertonic Solution
• In an Hypertonic Solution,
the concentration of
dissolved substances in the
solution is higher than as
the concentration of
dissolved substances inside
the cell.
• Therefore, there is less
water outside the cell than
inside & water flows out!
– Animal cells shrink
– Plant cells become less firm
called plasymolysis…
• How does this explain why
plants will wilt without water?
Passive Transport
• Passive Transport
When the cell uses
NO ENERGY to
move particles
across the
membrane via
DIFFUSION
• Includes Water,
Lipids, and LipidSoluble proteins
• Why? The
membrane is
attracted to them.
• Viruses are non-living particles
of nucleic acid, protein and
some lipids that cause
influenza.
• Composed of DNA or RNA in a
protein coat called a capsid.
• Viruses that only infect bacteria
are called bacteriophages.
• Named after their disease or
discoverer.
• Likely evolved later since they
are dependent on living things.
• Why Non-Living?
– Cannot reproduce without
infecting a host cell
– Do not grow and develop
– Do not respond to the
environment.
Viruses
Viral “Reproduction”
• Lysogenic cycle
– Virus attaches to host cell
– Inserts viral nucleic acid and
inserts it into the host
cell’s chromosome
(prophage)
– Gets replicated as host cell
divides (through mitosis)
– Can remain inactive for a
long period of time.
Like Bacteria, Viruses produce disease by disrupting the body’s normal
equilibrium. They either directly attack cells or cause cells to change their
patterns of growth or influence their function in the body.
Lytic Cycle
• Lytic cycle
– Starts as the lysogenic
cycle until triggered.
– Takes over cell
machinery to make
virus only! (Chops up
cell’s DNA to shut
down all defenses.)
– Viruses are assembled
in the host cell
– Burst out of the host
cell releasing new
virus
• 30 min = 200 viruses
Earth History
Earth History:
• Evolution is studied using concepts about earth history. The earth is
between 4.3 and 4.5 billion years old.
• Approximately 3.9 billion years ago, the surface was likely cool
enough for water vapor to condense. (Oceans formed.)
• Many of these events and organisms are recorded on the
geologic time scale.
•
As geologists provided evidence
about the age of the earth and the
rate at which changes happened,
biologists began to suspect that life,
and life forms also changed over the
same time.
Geologic and evolutionary change is
a long and slow process.
People wondered, how did life arise?
http://www.youtube.com/watch?v
=QDqskltCixA
Key Scientists – Origin of Life
Sidney Fox (1912- 1998)
• -Studied the development of the first cells;
found structures that have some cell life
characteristics.
•
•
•
•
•
•
•
•
Microspheres – microscopic droplet
enclosed by a membrane of organic
molecules. (Predominantly proteins.)
They can form buds, split and take up certain
substances from surroundings.
Sydney Fox produced protocells by heating
solutions of amino acids.
Microspheres
Coacervates – small organic droplet formed
by different types of organic molecules.
They can grow and take up substances from
surroundings. (lipid bi-layer)
NOTE: These are NOT ALIVE  no
heredity, instead of reproduction, they form
spontaneously under proper conditions.
Remember back to the Ecology unit, what are
some of the criteria to be considered living?
What is something else you know of that is
not considered to be alive?
Coacervates
Key Scientists
– Origin of Life
• Lynn Margulis (1938)
• Conducted experiments in the
1960’s
• Evidence:
– 1. Mitochondria and
Chloroplast DNA is similar to
bacterial DNA.
– 2. Mitochondria and
Chloroplasts have ribosomes
who size and structure
resemble bacteria.
– 3. Mitochondria and
Chloroplasts reproduce by
binary fission like bacteria.
• She determined the
endosymbiont theory that ancient
prokaryotes became the first
The Evolution of Cells
• 1st cells were prokaryotic heterotrophs.
Chemosynthetic bacteria came next like
archaebacteria.
• Photosynthetic cells came later and added
oxygen and the ozone to the atmosphere.
• Allowed for eukaryotes because the new ozone
layer protected from UV rays and oxygen
allowed for aerobic respiration.
Origin of Eukaryotic Cells
• Endosymbiont Theory:
Eukaryotic cells arose from
living communities formed by
prokaryotic organisms.
• The evolution towards
eukaryotic cells began between
1.5 and 2 billion years ago in
what is known as
“endosymbiosis”: an internal,
mutually beneficial relationship.
• Small aerobic prokaryotes are
thought to have entered and
lived inside larger anaerobic
prokaryotes. Later additional
small photosynthetic
prokaryotes are also thought to
have entered and lived inside.
• This is huge!
Chloroplasts!!
What is some evidence that you know of
that would lead you to think that
chloroplasts and mitochondria are
unrelated to our genetic history?
Early Life on Earth: What we
know
now!
Early Life on Earth:
• It is known that at the beginning there was little to no oxygen
available in the earth’s atmosphere. All living things must have been
anaerobic.
• The small size of the microfossils found indicates early organisms
were prokaryotes. Likely these were heterotrophs (does not make
their own food) that ate spontaneously formed organic compounds.
• Supply and Demand: as the supply of
these compounds became scarce, it
became necessary to evolve.
• Became Autotrophs (can make own food).
Early Life on Earth: What we
know now!
•
•
The “archaebacteria” of today are likely similar organisms to those early life
forms.
Archaebacterium – Kingdom of unicellular organisms that live in anaerobic
marine sediments.
-
They learned to use chemosynthesis: CO2
is the carbon source for needed organic
molecules, energy is obtained through
chemical oxidation of inorganic molecules.
•
Oxygen, as it became present in the atmosphere was often harmful to early
unicellular organisms, but by 3.5 billion years ago, some life forms had become
photosynthetic and oxygen in the atmosphere increased.
•
Evidence of a group similar to the cyanobacteria of today;
Cyanobacteria – (blue green) a group of
photosynthetic unicellular prokaryotes.
The Cell Theory
• Cell Theory:
1. All living things are
composed of cells
2. Cells are the basic living
units of all organisms
3. New cells are produced
from existing cells
-a cell divides to form two
identical cells
Virchow
7-1
• Cells are the basic unit of life
– Unicellular Organisms: Bacteria
– Multicellular Oganisms: Animal & Plant
Cells
Muscle cell
Pancreatic cell
Blood cell
All Cells have 3 characteristics:
1. surrounded by a barrier called a
cell membrane
2. have biological information (DNA)
3. have cytoplasm
Two Main Groups of Cells
• Prokaryotes
– NO membrane bound
organelles
– has circular DNA, no
nucleus
– cell functions carried out in
cytoplasm
– unicellular
– Example: Bacteria
• Eukaryotes:
– membrane bound organelles
– DNA is in the nucleus
– cell functions carried out by
organelles
– Most multicellular
– Example: Animal & Plant Cells
Eukaryotic Cell Structure
• Nucleus – contains DNA that codes for
proteins
• Cytoplasm – the portion of the cell outside
the nucleus; “jelly-like” fluid
www.nerdscience.com
7-2
Inside the Nucleus
• Nuclear Membrane – surrounds the
nucleus.
• Chromosomes – folded and twisted strands
of DNA in the nucleus.
• Nucleolus – makes ribosomes.
www.nerdscience.com
7-2
Inside the Nucleus
Nucleolus
Nuclear Envelope
www.nerdscience.com
7-2
Journey to the center of the cell!
An explanation of the cell organelles.
Use your paper to keep up and write down their functions.
Page 1: Once Upon a time…
There was a young girl
named Samantha. She
lived in a little town called
Carrboro.
She lived there with
her little dog Auggie.
One day there was a
big tornado and she and
her dog got whisked into
the air and transported to
a strange new world!
Page 2:
Samantha awoke in
a crazy new world and
said, “where am I?”
She felt that she was
stuck in some gooey
liquid and saw that her
dog was too although
Auggie looked very
different than before.
Where am I?
Then Auggie spoke
and she said, “this goo is
likely cytoplasm, the
liquid gel inside of all
eukaryotic cells. It acts
as a cushion and support
for the organelles!”
She continued, “kind
of like the packing
popcorn in shipping
boxes.”
Page 3: Who am I?
What
happene
d to me?
Cool! I
mean
“Woof!”
Hi
there!
Shocked that her dog
spoke, Sam looked and saw that
she was made of stacks and
green.
“You’re one of us,” a
mysterious voice said. “You’re
a chloroplast! Chloroplasts
trap light energy to be used by
plant cells.”
“Kind of like how solar
panels collect the sun energy to
be used later.” The voice
continued.
“Chloroplasts are only
found in plant cells, Auggie
exclaimed, “so that helps in our
mystery!”
Page 4: What happened to my Dog!?
Samantha was a bit
concerned about being
turned into a chloroplast,
but she was a bit more
curious about her dog.
Knowing now her dog could
talk, she asked her, “Auggie,
what the biscuits happened
to you?”
“I believe I am a
Ribosome. I help read DNA
and make it into protein for
the cell. We’re kind of like
the workers of the cell; the
cell’s best friend!”
Ribosome is
my name and
Protein is my
game!
Page 5: Okay, now let’s get out of here!
It’s like our
own
skeletons!
As Sam and Auggie
swam through the
cytoplasm, they headed past
all of these tubes and
filaments that kept getting
in their way.
“What is all of this stuff
Auggie?” Sam asked.
“This is likely parts of
the cytoskeleton that acts
to help support the cell.
Kind of like the concrete
blocks and structural
supports .” Auggie replied.
Page 6: Leaving is not so easy!
Samantha and Auggie reached the
end of the cell and found a security
guard at the cell boundary.
“Who are you?” asked Samantha.
“I’m the plasma membrane and I
act as the bouncer for the cell. I say
who goes in and who goes out.”
He continued, “Since this is a
plant cell, there is also another layer
outside of the membrane called the
cell wall which acts like a city wall
around a city. There are not present in
animal cells.”
“You two, my friends, are not
leaving.” The membrane added.
“If we want to leave, we’re going
to have to see the wizard or the
nucleus of the cell!” Said Auggie.
Come on
Sam, let’s go
see the
I had a
wizard.
feeling that
this wasn’t
going to be
easy.
Page 7: A new friend who needs some heart.
I just need the heart
to start making
energy again!
Let’s
keep
going!
I wonder
who else
we will
meet?
On the way we bump into
an organelle that seemed
unhappy.
“Hi, I’m a mitochrondrion,
I make energy for the cell,
kind of like the power plant
for a factory.”
“Lately I haven’t had the
heart to do it anymore and I
don’t know what to do!”
Auggie added, “I know!
Let’s all go see the Nucleus
and he’ll tell us what to do!”
The three then set off
looking for the Nucleus.
Page 8: A new friend who needs a brain.
While traveling with their new
friend, they passed by another organelle
with obvious issues. “And who are you
that is so blue?” Auggie asked.
“I’m the Golgi Apparatus, I package
proteins from Ribosomes and send them
out the rest of the cell, kind of like the
post office does for letters in a town.”
“What are those weird little things
coming off of you?” asked Samantha.
“Those are called Vesicles. This is
the transport method I move out
processed proteins. They are like the
letters from the post office.
“However, lately I’ve forgotten how
to package all these proteins so I haven’t
been doing my job and I don’t know
what to do!” He exclaimed.
Samantha told him, “Well, we’re all
off to see the Nucleus to get his
guidance, do you want to come?”
“Sure!” The Golgi Apparatus
exclaimed and happily joined the gang.
I need a brain to
figure out what to
do!
How do
you do?
Oh dear,
who
else?
Cool!
Another
friend!
Page 9: A new friend who needs some courage!
I need the
courage to do
my job again!
We’re going to
see the nucleus! I
bet he can help
us!
“I used to be scary,” said the
Lysosome. “I’m filled with
digestive enzymes and my job is
to digest and eat old cell parts
and microbes that enter the cell.
I’m kind of like the garbage
disposal of the cell. Everyone
fears me, but lately I haven’t had
the courage to go out and eat
anything!”
Alright, it’s getting
“Well,” Auggie started and
crowded here, let’s
then was cut off by Samantha.
go!
As the foursome moved towards the
“Blah, blah, you wanna see
nucleus, they encountered a dangerous
the Nucleus and try to solve your
foe! “Who are you?” Auggie timidly
problem?” Sam interjected.
asked. “I’m the … uh, the Lysosome.” It
“Sure!” the Lysosome replied
replied fearfully.
and off they went.
“Oh, he’s not scary, just scared!”
exclaimed Sam.
Page 10: Follow the Yellow Brick ER
“Oh, I get it,” said the
As our heroes went further to
the nucleus, they found a road mitochrondrion. “This is the
that led straight to it! “What is Endoplasmic Reticulum or ER.
this strange place?” asked Sam. It is the site of all chemical
Just then, Auggie perked up, reactions. It is like the assembly
starting barking and ran straight line for the cell.
The Smooth ER doesn’t have
to it.
any ribosomes, but the Rough ER
contains most of the Ribosomes.
Maybe that’s what Auggie went to
go see, the other Ribosomes.”
“WAIT! Auggie, come back!”
Shouted Sam. It was too late,
Auggie had ran ahead on the ER
Follow
right to the exterior of the
that dog!
Nucleus.
Page 11: Get Auggie Back!
The group chased after Auggie
up until they reached the nuclear
membrane where Auggie (because
she is a small ribosome) jumped in
through one of the small holes.
We can sneak in
through one of
those nuclear
pores!
“We have to sneak in, we have to
get Auggie back!” Sam cried.
“The Nuclear membrane is just
a membrane that separates the DNA
from the rest of the cell so it doesn’t
get damaged. It is kind of like a
plastic holder around a cell phone
or plastic shrink wrap! So it won’t
be so bad to go through, we’ll just
have to push through one at a time!”
Said the Lysosome.
The group snuck into the
nucleus and continued their search
for Auggie and the Wizard inside
the Nucleus.
Page 12: Inside the Nucleus…
“Auggie, Auggie, come here
girl! Where are you?” Called
Samantha.
“There she is!” said the
Golgi Apparatus. “Over there
with the Nucleolus!”
“What’s a nucleolus?” asked
Samantha.
“The Nucleolus is the
organelle inside the nucleus
that makes Ribosomes. It is
kind of like the Boss of all the
Ribosomes.”
Sure enough, Auggie was
wagging her tail next to the
Nucleolus which was giving
her some treats.
Treats are so
awesome!
You are such
a bad dog!
We were so
worried!
Page 13: Auggie
We’ve got to
be getting
close to the
Wizard!
& the Nucleolus
“Wait, so exactly who is
Yeah!
the wizard of the cell?” asked
Sam.
“That would be the DNA of
the cell,” the Mitochondria
Cool!
replied.
“The DNA is the genetic
code that makes all the
Ugh, I’m
organelles and enzymes
About
not feeling
inside the cell. It acts as the
time!
so good…
brain of the cell, directing all
of the cell activities. The DNA
lives inside of the Nucleus.
All Plant and Animal cells
“Auggie, there you are! You had
have DNA in their nucleus.”
us so worried!” exclaimed Samantha.
“Even prokaryotic cells
“Sorry,” Auggie said, “I knew if I
have DNA.” added the
found the Nucleous, then the wizard Lysosome.
would be close by!”
Page 14: Meeting the “Wizard.”
Finally, the group with Auggie
back, reached the DNA at the
center of the Nucleus.
Timidly, they approached the
DNA wizard and each organelle
with the group asked the wizard
for what they needed.
The Mitochondria went first and
got the heart to make energy again.
The Golgi Apparatus went next
and got the brain he needed to
package and sort proteins again.
The Lysosome went last and got
the courage to hunt down old
organelles , bacteria and viruses to
digest again.
Lastly, Samantha and Auggie went
before the DNA to ask their question
about why they were inside the cell.
I’ve found my brain
to package
proteins!
I’ve found
my heart
to make
energy!
I’ve found my
courage to digest
things, but I still don’t
feel good…
Page 15: The Test!
“Um, all knowing
Wizard, I mean
DNA, sir…” Sam
stammered,
“could you help us
find our way back
home?” she
pleaded.
“DEPENDS,” boomed the
DNA. “YOU MUST PASS MY
TEST ON CELL ORGANELLES
TO SEE IF YOU ARE WORTHY
TO GO TO THE VACUOLE AND
RETURN TO YOUR NORMAL
LIVES!”
Wait, how can we find the
vacuole?” Samantha asked.
The mitochrondrion
replied, “The vacuole is like
a storage area of the cell for
water or food items. It is
kind of like a giant storage
unit like a trunk or closet.
It’s huge in plant cells, you
can’t miss it. In animal cells
there are more of them, but
not as large.”
“Okay,” said Auggie.
“Let’s ace this test!”
Your Turn!
Identify the Letters to the Organelles!
The group put all their
heads together and came
up with a list of answers to
DNA’s test.
Luckily, since Samantha
and Auggie went around
and made friends with all
the organelles, it was an
easy job!
Help the group by
identifying the organelles
in your notes!
Page 16: Answers to DNA’s Test
The group put all their
heads together and came
up with a List of Answers.
Double check with
your list in your notes and
see how you did!
Correct any answers
you did not get the first
time!
A – Nucleus
B – DNA
C – Nucleolus
D – Nuclear Membrane
E – Rough ER
F – Smooth ER
G – Vacuole
H – Cytoskeleton
I – Chloroplast
J – Cell Wall
K – Plasma Membrane
L – Mitochondrion
M – Vesicle
N – Golgi Apparatus
O – Lysosome
P – Cytoplasm
Q - Ribosome
Page 17: One Last Question!?
“BEFORE I CAN LET
YOU GO, I WANT TO SEE IF
YOU HAVE TRUE
KNOWLEDGE OF
ORGANELLES.” The DNA
demanded.
“WHICH ORGANELLE
IS NOT FOUND IN PLANT
CELLS, BUT ONLY IN
ANIMAL CELLS THAT
HELPS IN CELL
DIVISION?”
Page 18: The last question… answered!
The group was dumbfounded, all
of them had spent their entire lives
inside of a plant cell and had no idea
what was the unique organelle of an
animal cell.
The Lysosome got so nervous,
he vomited on the floor all of the
contents in his gut!
Then, up popped an undigested
bacterium that must have escaped
death due to the previous lack of
courage from the lysosome.
“I know the answer you seek!”
cried the bacterium. “It’s a
Centriole! Centrioles are only
found in animal cells and act as
fishing poles to separate the
chromosomes in cell division!”
Oh, excuse me!
Eww!
Hmm.. Hey
are you going
to eat that?
Ugh, it was getting
stuffy in there!
Page 19: Onto the Vacuole and Home!
“YES, THAT IS
CORRECT.” Stated the DNA.
There’s no
place like
Carrboro,
there’s no place
like Carrboro!
Onto
the
vacuole
!
“NOW IF YOU WISH TO
GO HOME, FIND THE
CENTRAL VACUOLE OF
THE CELL AND SAY THE
MAGIC WORDS,
“THERE’S NO PLACE LIKE
CARRBORO!
“What are we waiting
for?” exclaimed Samantha.
“Come on Auggie, let’s go
home!”
And with that, the group
went to the Vacuole!
Page 20: Home Sweet Home
The group rushed to
the vacuole and said their
tearful goodbyes.
Samantha had learned a
lot from her organelle
friends and she would
never forget them.
Sam and Auggie
entered into the vacuole,
said the magic words and
then felt like they were in
a terrible storm!
We sure are
going to miss
you!
Thanks Samantha
and Auggie! We
couldn’t have done
it with you!
Epilogue
“Where am I? Who am I?
Am I still a chloroplast? Is
Auggie a talking Ribosome?”
Samantha said with a jolt
upright in her bed.
I bet she doesn’t
suspect a thing!
“No, no Samantha,” her
mother told her. “A tree
branch hit you on the head
during the storm and we
found you when Auggie was
barking and licking your
face. It was all just a
dream.”
Her mother left the room
and Auggie jumped on her
bed and said, “It was all a
dream so just go back to
sleep.”
Photosynthesis Overview
• Photo = light
• Synthesis = putting together
• Photosynthesis is the
process that plants use to
trap the sun’s energy and
build carbohydrates (called
glucose) that store energy
• Happens in 2 phases:
– 1) The Light (light dependent)
reaction creates ATP
– 2) The Dark (light independent)
reaction uses those ATP
molecules (from the light
reaction) to make glucose
Overview of Photosynthesis
The Role of Chlorophyll
• The Chloroplast is the
cell organelle where
photosynthesis occurs
• In the chloroplasts are
pigments that absorb
wavelengths of light
• Chlorophyll (a and b)
absorb all colors
except green so it is
reflected
• In Fall, trees reabsorb
chlorophyll leaving the
other pigments
visible
Summary: The light reaction
converts ADP and NADP+ into
ATP and NADPH with Oxygen
gas.
Light-Independent Reactions
• Does not need light
• Called the Calvin Cycle
• Uses CO2 to form
Carbohydrates
• Takes place in the stroma of
the chloroplast
• Called a Cycle because the
end products can be used
again to initiate the process
• Uses the NADPH and ATP
produced in the earlier light
reactions
http://www.tracy.k12.ca.us/thsadvbio/animat
ions/Photosynthesis.swf
Calvin
Cycle
• The Calvin cycle
uses the ATP and
NADPH from the
light dependent
reaction to create
sugar.
• Reactant: Carbon
Dioxide
• Product: a
6 Carbon Sugar
Calvin is in the dark
about
photosynthesis!
What’s the big deal about
Photosynthesis?
• The Calvin Cycle removes Carbon Dioxide from the Earth’s
atmosphere and creates sugars.
• Plants can use those sugars for food or to make larger
molecules like cellulose for growth and development.
• When we eat plants (or herbivores) eat plants, we use the
energy stored in the carbohydrates.
• A byproduct of our breathing is Carbon Dioxide, which is
used by plants for photosynthesis. It is also a greenhouse
gas contributing to global warming.
• Without plants to harvest the sun’s energy, there would be
no life for animals on Earth!
Cellular
Respiration
•
•
•
•
Cellular Respiration =
Process by which
mitochondria break down
food molecules to produce
ATP
Does not use Oxygen is
called Anaerobic
Does use Oxygen is called
Aerobic
There are 3 stages of Cellular
Respiration:
1) Glycolysis (Anaerobic)
2) Citric Acid Cycle (Aerobic)
3) Electron Transport Chain
(Aerobic)
Glycolysis - Anaerobic
• Glycolysis = series of chemical
reactions in the cytoplasm of a
cell that break down glucose (a 6
Carbon compound) into 2
molecules of pyruvic acid (a 3
Carbon compound)
• NAD+ accepts a pair of high
energy electrons to pass that
energy to other pathways in the
cell.
• 2 Molecules of ATP are used to
start Glycolysis and only 4 ATPs
are produced
• Net only 2 ATP
• Then pyruvic acid proceeds to the
Mitochondria to begin the Citric
Acid Cycle and the Electron
Transport Chain (in the presence
of Oxygen)
Anaerobic Processes
• Sometimes your cells are without
Oxygen for short periods of time
(during strenuous exercise, etc)
• In order to make ATP, the process
of Fermentation occurs after
Glycolysis until Oxygen becomes
available again.
• During fermentation, cells convert
NADH to NAD+ by passing high
energy electrons back to pyruvic
acid. This action converts NADH
back into the electron carrier NAD+
allowing glycolysis to continue
producing a steady supply of ATP.
• Some organisms simply live in
areas without Oxygen and must
produce their ATP this way.
• http://www.youtube.com/watch?v=
y_k8xLrBUfg
2 Anaerobic Processes:
Lactic Acid Fermentation & Alcoholic Fermentation
• Without Oxygen, the Electron
Transport Chain becomes
backed up since no Oxygen is
there to be the final electron
acceptor
• Pyruvic Acid + NADH →
lactic acid + NAD+
• Lactic Acid is the cause of
sore muscles.
• Certain organisms living in
anaerobic environments will
rely on this type of ATP
synthesis.
• Pyruvic acid + NADH →
alcohol + CO2 + NAD+
• Yeast use this type of
fermentation to create C02 and
ethyl alcohol.
Aerobic Respiration
• Most efficient type of
Cellular Respiration
• Requires Oxygen
• Occurs in 3 steps:
– 1) Glycolysis
– 2) Citric Acid Cycle
– 3) Electron Transport
Chain
• Glycolysis is the only
step that is Anaerobic
• The other Anaerobic
process was
fermentation
Aerobic Respiration - Mitochondria
Remember, Glycolysis breaks
down 1 glucose into 2 pyruvic
acid molecules
Heads to Mitochondria for
Aerobic Respiration
Citric Acid Cycle occurs in the
outer mitochondrial membrane
Calvin Cycle – glucose was
formed
Citric Acid Cycle – glucose is
being broken down
For 1 Glucose molecule, 1 ATP is
made for every turn of the cycle.
http://www.wiley.com/college/prat
t/0471393878/student/animation
s/citric_acid_cycle/index.html
Electron Transport Chain 1:2
• Very Similar to the ETC of the
thylakoid in plants
• NADH and FADH2 pas
energized electrons from protein
to protein releasing small
amounts of energy
• A Concentration gradient
forms in the mitochondria
– Hydrogen ions inside
– Lack of Hydrogen ions
outside
• An Electrical gradient forms in
the mitochondria (H+ ions
pumped inside)
– Positive in the center
– Negative on the outside
Electron Transport Chain 2:2
• The final electron acceptor is Oxygen
• Yields Carbon Dioxide (CO2), 2 Water, and 36 ATP
• Most efficient process since anaerobic respiration
only yields 2 ATP.
• http://www2.nl.edu/jste/electron_transport_system.ht
Overview of Cellular Respiration
Comparing
Photosynthesis & Respiration
• PHOTOSYNTHESIS
– Food accumulated
– Energy from the Sun
stored in Glucose
– CO2 taken in
– Oxygen given off
– Produces Glucose from
PGAL
– Goes on only in Light
– Occurs in the presence
of Chlorophyll of Plants
only
– Chloroplasts
• RESPIRATION
– Food Broken Down
– Energy of Glucose
Released
– CO2 given off
– Oxygen taken in
– Produces Carbon Dioxide,
Water & ATP
– Goes on Day & Night
– Occurs in all Living Cells
(Plants and Animals)
– Mitochondria