Download Chapter 9 Lecture

Chapter 9 Lecture
Chemical Energy/ Cell Respiration
Food provides chemical building blocks to make muscle and new cells. It also provides energy for
growth and movement.
There is a lot of energy in food. One gram of sugar had 4 Calories which is 4000 calories. The capital
“C” means it is a kilocalorie. 1C= 1000 c. Our ___________________measured in Kilocalories.
Our body slowly releases this energy in the form of ______________________ (Latin: Sugar-cutting).
This slow release is important. You wouldn’t want your car to burn up all the gasoline at once. The
same is true with your body.
Cellular respiration is the process that releases energy by breaking down food molecules and it
must have __________________________.
Key Notes
ATP, used for cell energy
NADH: Electrons holders to be converted later top ATP
FADH: Electrons holders to be converted later top ATP
Glycolysis takes place in the _________________________. The other stage of the cell respiration
takes place inside the mitochondria and the cell membrane of the mitochondrion.
6O2+ C6H12O6  6CO2 + 6H2O + energy
Notice the formula is opposite from ___________________________
GLYCOLYSIS
One glucose molecule (C2H12O6) is broken in half, which are 2 molecules of __________ ________
Glucose
Needs Energy
______ATP Units
Pyruvic Acid (next stop Krebs Cycle)
Releases
_____ATP Units
To break the glucose in half requires 2 units of ATP energy. When the 3 carbon molecules are
rearranged however, they get 4 ATP, for a net gain of 2 ATP.
NADH is another energy ________________________ molecule.
It holds the electrons that are removed from the 2 pyruvic acid molecules and then later
____________________ them to create more ATP in the mitochondrion.
Thousands of ATP each millisecond can be produced in Glycolysis.
It doesn’t even need oxygen from the cell.
This part of cellular respiration is ___________________________.
If oxygen is present the 2 pyruvic acids go to the_______________________.
Sometimes oxygen is not present in the cell or not enough oxygen is present.
When this lack of oxygen occurs, the 2 pyruvic acids go through a process called
_________________________.
Step 1: The NADH electron holder gives back the 2 electrons to the Pyruvic acids.(pg 224)
Step 2: the e- enhanced pyruvic acid molecules can go to lactic acid fermentation or alcoholic
fermentation.
Step 3: Alcoholic or Lactic acids fermentation (only yeast and bacteria create _________________)
Alcoholic Fermentation
Bread, Wine, Alcohol
Pyruvic acid + NADH  alcohol + CO2 + NAD+
Bread / Pizza dough rises because of AL-Ferm. CO2 is given off in beer and the bread rises due to
CO2 bubbles. Alcohol evaporates when the bread is cooked.
Lactic Acid Fermentation: L-A Ferm: L.A.F
The pyruvic acid is converted into lactic acid which is still 3-carbon molecule, but it has a different
structural shape. L.A build up is what makes ____________________ store and burn. It takes a few
days for the LA to be broken down in the muscle cells.
Krebs’s Citric Acid Cycle Nobel prize 1953 ( If there is Oxygen!)



Aerobic- requires oxygen
There are parts- steps involved to get ALL the energy from the pyruvic acid.
Takes place in the mitochondrion
Phase A pg227
1. Py-A, enters the mitochondrion and ________________ one carbon to create CO2.
2. The 2 carbon molecule attach to a Co-enzyme ( part vitamin/ part enzyme)
3. Acetyl-Co enzyme connects to the 4 carbon citric acid molecules- the first molecule of the
Krebs cycle. ( the Co-enzyme A detaches to be reused)
Phase B
1. Citric acid and the Acetyl formed a 6 carbon molecule but one Carbon is released as Co2.
2. This allows energy ( electrons) to be stored by NADH
3. the citric acid removes 2 more carbon which create more NADH and one ATP
Phase C. Net profit of one Pyruvic acid molecule
1 _________
3 _________
1 _________
Summary of one glucose molecule before electron transport
Glycolysis= 2 ATP and 2 NADH
( for both pyruvic acids) Krebs Cycle= 2 ATP, 8 NADH, 2 FADH2
Before going to the ETC ( electron transport chain)
2 units of ATP- usable energy
8 NADH
2 FADH  stored electron energy to be converted into ATP, by the ETC.
The ETC converts high energy electrons into ATP

The electrons are removed from the NADH and FADH by integral channel proteins in the
cell membrane of the mitochondrion.

As each e- is moved from protein to protein it creates water molecules by attaching to H+
ions in the cell.

The oxygen that you breathe is where the O2 comes from to create the water.

The movement of positive H+ ions and the movement of negative e- given off from NADH,
cause the plasma membrane to flip flop from positive to negative inside the mitochondrion.

When the inside is negative, an H+ ion enters through the specialized protein channel
attached to an enzyme make ADP turn into ATP.
On average, each electron (e-) makes 3 ATP.
Fill out pg 229
Krebs’ Cycle and ETC
Total ATP Produced
Energy and Power Shopping(or other Moving Activity)
Given:
1. Muscles have a small amount of stored ATP for energy
2. Muscles can get energy by LA- Ferm.
3. Muscles with 2 can get 36 ATP unit from glucose stored in cells
Speed shopping- Anaerobic
Huge shoe sale! Doors open at 8:00 am! Only one shoe size for each other type of shoe! A
certain biology teacher who has a severe shoe habit has to park 300 meters away from the door!
There are others that are also in the parking lot. There are others that are also already standing at
the door.
Ms. Bio must sprint to the door and push her way to the front.
Ms. Bio would be using her quick stored energy in her muscles.
Sadly, this energy last for a few seconds or in her case 50 meters. Her muscles are now
producing lactic acid. However this lactic acid energy will only last for about one minute.
After a minute the muscles cannot keep the high speed. Will Ms. Bio make it to the door? Can she
sprint faster than the other ladies in the parking lot?
No! She wore a pair of 4 inch strappy sandals. The lady who beat her was wearing “sensible”
shoes. “Sensible” means ugly shoes.
Ms. Bio is determined to buy shoes. She no longer has to sprint. She jogs over to her size. Her
muscles are in aerobic cellular respiration. She can shop for hours now and not just for shoes!
Real Lesson:
Lactic Acid fermentation can only supply a small amount of energy before the muscle fatigues. Or
If your muscles cannot get oxygen fast enough for the work load you are requiring, it will resort to
anaerobic fermentation.
Your muscles have a type of sugar stored called glycogen. This sugar will supply energy for about
20 minutes, after 20 minutes such as all day shopping; other molecules such as fat are used for
energy. Sadly one must exercise 20 minutes before any fat is even burned!
* Fatty acids and amino acids also enter the Krebs Cycle. Fats produce over 2.5 x the ATP energy
of one glucose.