Transcript Warmup for Monday 12/3 and Powerpoint on Cellular Respiration

WARM UP
Take today’s handout.
Get out your journal. If you do not have a
journal, you will need a sheet of lined
paper.
Turn to page 37 of your journal, which is
the table of contents for the Biochemistry
Unit.
Add the following two entries:
Grain Elevators
48 Cellular
49
Respiration Notes
Grain Elevators
We are going to do a writing assignment
on Journal page 48.
Turn to Page 48 of your journal.
Title the Page “Grain Elevators”
If you don’t have your journal, do this on a
separate sheet of paper!
Grain Elevators
(information – not notes)
A grain elevator is a huge group of
buildings used to store grains like wheat,
oats, and barley, after it is harvested.
We are about to see two movies. One
shows a truck driving in to deliver wheat to
a grain elevator.
The second is a news report about a
problem at a grain elevator.
Grain Elevator Delivery
Grain Elevator News Report
Grain Elevator
QUESTIONS TO ANSWER in your journal
on page 48:
In your own opinion, why would a building
full of wheat explode?
Where does the energy for the fire come
from?
EXPECTATION: a paragraph of at least 5
sentences.
Cellular Respiration Notes
As we go through this,
complete your handout for
page 49.
Heterotrophs
If you cannot do photosynthesis like all
plants, some protists, and some
prokaryotes, you must collect your energy
in another way.
All animals, all fungi, some protists, and
some prokaryotes are heterotrophs, or
“other makers,” which means they
consume calories.
We get your energy from food
Carbohydrates, proteins,
and fats are reservoirs of
energy
A series of chemical
reactions known as
cellular respiration makes
that energy can become
available to cells.
The process starts in your digestive
system
The large molecules in food are broken
down into small molecules.
Proteins become amino acids.
The process starts in your digestive
system
The large molecules in food are broken
down into small molecules.
Starches become sugars.
The process starts in your digestive
system
The large
molecules in food
are broken down
into small
molecules.
Lipids break
down into
glycerol and fatty
acids.
The one most important molecule
for making energy is a specific
sugar, glucose.
Your body
can change
fats or
proteins into
glucose, if
necessary.
Energy = Calories.
One physics calorie will increase the
temperature of 1 g water by 1 C.
A biology Calorie is equal to 1000 physics
calories.
One gram of fat produces about 9
Calories; a gram of carbohydrate or of
protein produces about 4 Calories.
Glucose is Best!
When you need to burn lipids or amino
acids, the process is less efficient, since it
takes energy to convert them into glucose
before you can use them for cellular
respiration.
When you convert amino acids into
glucose, you also have to remove the
nitrogen (“deamination”) – this waste is
removed in your urine.
The most important organelle in
each cell is your mitochondria.
Every eukaryotic cell has mitochondria
The more active the cell is, the
more mitochondria it has.
Which type of cell has more mitochondria:
liver or fat?
Origin of Mitochondria
Scientists believe
that mitochondria
were once bacteria,
and are now
symbiotic with
eukaryotic cells.
One piece of
evidence for this
theory is that
mitochondria have
their own DNA.
Endosymbiosis
The Structure of the Mitochondria
Outer
A lipid bilayer, the
outside layer of
Membrane
the cell.
Cristae
Folds made of the
inner membrane.
Matrix
The cytosol fluid
inside the
mitochondrion.
Three Steps of Cellular Respiration
1. Glycolysis
2. The Krebs Cycle
3. The Electron Transport Chain
Homework
Update your journal: On page 49:
summarize all of today’s notes and
thinking in a paragraph. Then write four
study questions for yourself.
Did you finish your paragraph on page 48
about Grain Elevators? If not, you can do
that now.
You have until 12/21 to finish the five
coloring pages
THE STEPS OF CELLULAR
RESPIRATION
There are a few other steps, but you are
only responsible for these three.
You can fill in the graphic organizer as we
go….
Glycolysis
Where it happens: Glycolysis occurs in the
cytoplasm of the cell.
It is the only step that does not occur in
the mitochondria.
Glycolysis
Summary of what happens: Glycolysis
means “break sugar” Glucose is
broken in half.
Glycolysis
The reactant is a molecule of glucose.
NOTE: Oxygen is not needed for this
step.
Glycolysis
The products are two “half-glucose”
molecules, called pyruvate and a small
amount of ATP.
Step 2: The Krebs Cycle
This cycle is also called
the Citric Acid Cycle or
tricarboxylic cycle or
TCA.
You should know all
three names, since a
test might use any of
them, even though your
book only uses “the
Krebs cycle”
The Krebs Cycle…
occurs in the matrix of the mitochondria.
The Krebs Cycle…
is a whole
long series of
complicated
chemical
reactions ….
…involving
all sorts of
chemicals –
pyruvate,
pyruvic acid,
Acetyl Co-A,
acetate, and
many
enzymes
The Krebs Cycle
The process starts where glycolysis ends,
with pyruvate turned into a new molecule
called “Acetyl Co-A’
Oxygen is also required.
The Krebs Cycle
The products include carbon dioxide, a
small amount of ATP and a lot of
electrons.
The carbon dioxide is waste.
The electrons are needed for the next step
Electron Transport Chain
This step happens in the inner membranes
(cristae) of the mitochondria.
Like the Krebs Cycle, it has many smaller
steps.
This is the part of cellular respiration which
releases the most energy.
Electron Transport Chain
This process
starts with the
electrons
released by the
Krebs cycle.
Oxygen is also
required.
A chemical called
ADP is also a
reactant.
Electron Transport Chain
The products of
the electron
transport chain
are water and a
large amount of
ATP.
Oopsies!
If there is no oxygen, the Krebs Cycle and
Electron Transport Chain can’t happen.
Some cells stop with glycolysis.
Some cells perform anaerobic (without
oxygen) fermentation.
Fermentation
Fermentation creates poisons, like
methane gas, lactic acid and alcohol.
Some humans make a lot of money by
fermenting compost or alcoholic drinks.
Making wine or beer involves
fermentation, and eventually kills the
yeast.
Lactic Acid?
Remember: lactic acid does not cause
muscle soreness!
It is caused by microscopic tears in the
muscle.
HOMEWORK:
Summarize today’s notes, and write at
least four study questions for yourself.