Chapter 7
Cellular Respiration
Vocabulary Pretest Section 1
1. Cellular Respiration
2. Pyruvic Acid
3. NADH
4. Anaerobic
5.
6.
7.
8.
Aerobic Respiration
9. Lactic Acid Fermentation_______
Glycolysis
10. Alcoholic Fermentation_______
NAD+
11. Kilocalorie__________________
Fermentation______________________________________________
Cellular Respiration
*Cellular Respiration—the process by which cells ________________________________;
Oxygen combines with _____________ to form __________________________________
*Equation:
*The equation is a _____________________ of a very complex process.
*The purpose is to convert ____________ into _______________ by breaking down
_____________________________.
*If oxygen is present = ______________________________(which is most efficient)
*If no oxygen is present = ______________________________(which is much less efficient)
*Both types start with a process called ___________________________
Glycolysis
*First stage of _____________________________
*Means “_________________________”
*Occurs in the ____________________
*No _____________________ is needed
*Glucose molecules are broken down into two 3-carbon molecules of __________________
*Pyruvic acid is then used in the ___________________
*Specific __________________________________
*_____________________________ are produced
*_____________________________ of NADH (an electron carrier molecule) are produced
4 Stages of Glycolysis
1. 2 phosphates are added to _______________. They are released from 2 molecules
of _______ (changing it to _________). Draw the first stage of Glycolysis.
2. The glucose molecule (with its 2 phosphates) is then _________________________
(glyceraldehyde 3-phosphate) Draw the second stage of Glycolysis.
3. Each ________ gets oxidized by adding another phosphate group. Also, electrons
and __________________ are removed from the 3C molecule. They are added to
______________________ (nicotinamide adenine dinucleotide) to create
____________ and __________. These will go to the ________________________
Draw the third stage of glycolysis.
4. The phosphate groups are removed from each molecule creating 2 molecules of
__________________ (3C). The phosphates are added to 4 molecules of _______
producing __________molecules. Draw the fourth stage of glycolysis.
Summary of Glycolysis
*___________________ (6C) is broken into two molecules of _____________________ (3C)
*If oxygen is available, the ___________________ will move into the __________________
and aerobic respiration will begin.
*___________ molecules are produced. ________________ to break apart the next glucose
molecule and keep glycolysis going.
*This leaves a net yield of _______________________ for use by the cell.
*Two _______ are converted into __________ and _______. These go to Electron Transport
Efficiency of Glycolysis
*Measured in ____________________ (kcal) One kilocalorie = _____________ (cal)
*Complete oxidation of glucose releases _______________
*Production of ATP absorbs ______________
*2ATP are produced from every glucose molecule broken down by glycolysis
*Efficiency formula:
Section 2 Vocabulary Pretest
1. Mitochondrial matrix
2. Acetyl CoA
3. Krebs Cycle
4. Oxaloacetic Acid________________
5. Citric Acid_____________________
6. FAD__________________________
Aerobic Respiration
*In most cells, the __________________________ produced in glycolysis enters the pathway
of ___________________________
*Aerobic respiration produces 20 times as much _____ as is produced by ______________
*______________must be available
*Two major stages: __________________________________________________________
Intermediate Step
*Aerobic Respiration takes place in the _______________________
*Before the Krebs Cycle can begin, each of the two ______________________________
must be converted.
*The pyruvic acid enters the ____________________________
*It reacts with a molecule called ___________________ to form ______________________
Draw the intermediate step:
*Notice that acetyl CoA only has
2 carbon atoms
*The lost carbon is released in a
molecule of _________
*A molecule of NAD+ is reduced to
__________________
*Since this happens to both molecules
of pyruvic acid the end result is:
_______________________________________
_______________________________________
_______________________________________
The Krebs Cycle
*Named for ___________________________
*It is a biochemical pathway that breaks down _____________________
*Two turns of the Krebs Cycle produce:
1. ____________________________
2. ____________________________
3. ____________________________
4. ____________________________
5 Steps of the Krebs Cycle
1. Acetyl CoA combines with ______________________________ to produce
Citric Acid. This regenerates and releases CoA.
Draw the first stage of The Krebs Cycle
2. ________________ releases a ________ molecule and is oxidized by losing a
hydrogen atom. This forms a new 5 carbon compound. The hydrogen atoms is
transferred to ___________, reducing it to NADH.
Draw the second stage of the Krebs Cycle
3. The 5 carbon compound now releases a ________ molecule and a hydrogen atom.
This creates a 4 carbon compound and the hydrogen atom is again added to
________, reducing it to ___________. A molecule of ATP is synthesized from ADP;
Draw the third stage of the Krebs Cycle
4. The 4 carbon compound releases a hydrogen atom which is used to reduce
_______(Flavin Adenine Dinucleotide) to _________ (FAD also accepts electrons
during redox reactions).
Draw the fourth stage of the Krebs Cycle
5. The 4 carbon compound now releases a hydrogen atom to regenerate oxaloacetic
acid, which can be used to start the Krebs cycle over again. The hydrogen atom
released again reduces ___________________________
Draw the last stage of the Krebs Cycle
Review of Glycolysis and the Krebs Cycle
*In Glycolysis, _________________ molecule produces _____________________molecules,
Which can then form two molecules of ______________________
*Both of the Acetyl CoA molecules enter the Krebs Cycle creating two turns of the cycle
*This produces _______________________________________________________________
(the CO2 is a waste product that diffuses out of the cell).
*The ________________ and _____________ molecules drive the next stage of aerobic
respiration---the ________________________________
The Electron Transport Chain
*The Electron Transport Chain, linked with ____________________ makes up the second
stage of aerobic respiration.
*Electrons are transferred from one molecule to another by several electron carrying
molecules located in the membrane of the ________________________.
*All steps occur in the _______________ (inner membrane) of the mitochondria.
Follow the steps of the Electron Transport Chain:
1. ATP is produced when __________ and ___________ release hydrogen atoms (this
regenerates NAD+ and FAD, which return to the Krebs Cycle to be reused). Each
hydrogen atom gives up electrons and hydrogen ions (H+)
2. The ________________ released move down the chain. They lose energy as they move
from molecule to molecule.
3. The lost energy pumps the _____________________ from the matrix to the other side
of the membrane.
4. A __________________________ ___of hydrogen ions across the membrane is created.
5. H+ are pumped back in by _______________________
6. ATP is made from ADP and ____________________
7. ______________ is the final electron acceptor and also accepts H+ ions to make
____________.
Efficiency of Cellular Respiration
*Through Aerobic Respiration, a maximum of _____________ molecules can be produced
from __________________________________.
2 come from ___________________
2 come from ____________________
32-34 come from the ______________________________
Fill in steps if you need them
*The actual number of ATP molecules generated through Aerobic Respiration varies from
cell to cell (36-38).
*Most ____________________________ produce only 36 molecules per glucose molecule
because the active transport of __________ uses up some ATP
*When 38 ATP molecules are generated the efficiency is calculated by the following formula:
*This is _________________ more efficient than glycolysis alone.
Anaerobic Respiration
*If _____________________is present, the Krebs Cycle and Electron Transport Chain can not
work.
*The cell must have a way to _____________________________________.
*Glycolysis would stop without a process to recycle NAD+ and NADH.
*It would use up all the NAD+, Glycolysis would stop and the cell would and die.
*Fermentation must kick in to prevent this.
Fermentation
*Fermentation is the chemical pathway that recycles NAD+ without oxygen. It keeps
glycolysis going. No additional _______ is made.
*Therefore, you still have a ______________________ efficiency rate for energy release.
*Two types of fermentation:
1. ____________________________
2. ____________________________
Lactic Acid Fermentation
*_______________________ is converted by an enzyme into __________________
*Two hydrogen atoms from NADH and H+ are transferred to ______________ to form the
Lactic acid molecule.
*NADH is oxidized to _________ and reused to keep glycolysis going.
*Occurs in foods such as _________________________
*Occurs in _______________________during hard exercise.
*Leads to sharp muscle pain----Slow Down!!
Alcoholic Fermentation
*Converts pyruvic acid to carbon dioxide and _________________________
*NAD+ is recycled in the same manner as before.
*Yeast uses this process---producing CO2----causing bread dough to rise.
*When the dough is baked, yeast cells die and the ________________________________