Download An Introduction to Cellular Respiration

Biology 30 - Ch. 6 – Cellular Respiration Notes
An Introduction to Cellular Respiration
• Humans and other animals consume food and convert it into a useable form
of energy called ____________________ often abbreviated as _________.
• The conversion of food energy into _____ is called __________________.
• There are two basic types of cellular respiration: ____________________.
• _______________ respiration requires ___________ and ______________
respiration does ________________________. _______________ is a type
of anaerobic respiration.
• Proteins, fats, and carbohydrates may be converted into ATP during cellular
respiration, but glucose is commonly used to examine the reactions involved.
• Respiration can be divided into three pathways:
• ____________________
• ____________________
• ____________________
• Glycolysis occurs in the __________________________ while the other two
stages occur in the ___________________________.
• Some great tutorials and animations about cellular respiration and
photosynthesis can be found at:
http://www.wwnorton.com/college/biology/discoverbio3/core/content/ch8/animations.asp
•
•
•
•
•
•
•
•
•
•
•
•
The Importance of ATP and NADH
Adenosine triphosphate is the molecule all cells use for ______________.
Muscle cells, nerve cells, bacteria, plant cells etc. all use ATP.
The purpose of cellular respiration is to ____________________________.
This occurs in the ____________________________ of our cells.
ATP: The Most Important Energy Storage Molecule
The only form of energy a cell can use is ATP
All the food we consume for energy is useless to our tissues unless it is
converted to a useable form ... ATP
ATP production and usage is best accomplished in the ________________
Adenosine Tri - Phosphate (ATP) acts like a ________________________
___________________________ when energy is required, and _________
___________________ during the storage of energy (Cellular Respiration).
NAD+ acts like a _____________________________________________.
The 'filled' NADH taxi ________________________________________.
Most important electron carrier is NAD+.
1
Biology 30 - Ch. 6 – Cellular Respiration Notes
• NAD+ acts as an oxidizing agent, accepts a hydrogen atom and one
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
electron, becoming NADH.
NADH can carry electrons on to another acceptor, thus being regenerated.
Enzymes coordinate these transfers.
The electron transfer process stores a great deal of energy which will
____________________________________________________________
Glycolysis
Glycolysis is the first step of _______________________________.
It occurs in the liquid cytosol of the cell.
During glycolysis a ________________________ is chemically snipped
into two three-carbon compounds called _________________________.
The food we consume is of no use to our cells until it is converted to ATP.
The conversion of ___________________________ is the ultimate goal
of cellular respiration.
During glycolysis the energy of glucose is released through a series of
reactions producing smaller quantities of useful ATP.
These enzyme controlled reactions slow down the release of energy so no
damage is done to the cell.
The amount of ATP that can be produced depends on ________________
___________________________________________________________.
Glycolysis Summary
Enzymes in cytoplasm catalyze series of reactions in metabolic pathway.
Requires some _______________________________________________.
Reactions of the 2 invested ATP split one 6-carbon sugar into two 3-carbon
sugars.
2 NAD+ accepts high-energy electrons from the split glucose molecule.
Enough energy is generated to attach phosphates to 4 ADP to make 4 ATP
(+4 ATP).
Not much energy, but fast and no oxygen was required (anaerobic). 5
The result of glycolysis is a net gain of ____________________________
____________________________________________________________.
A great deal of energy is still available in the ______________________
____________________________________________________________.
This energy will be released during the Kreb's Cycle and the Electron
Transport Chain in the mitochondria.
If no oxygen is present the NADH molecules and pyruvic acid ferment.
2
Biology 30 - Ch. 6 – Cellular Respiration Notes
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Fermentation
________________________were produced via the process of glycolysis.
In many cells, oxygen may not be present in sufficient quantities to break
down the pyruvic acid to produce another 34 ATP.
In the absence of oxygen at this point the pyruvic acid generated by
glycolysis accepts hydrogen from _______________________.
This is fermentation. Pyruvic acid is converted to a less harmful substance
and the NADH supplies the H atoms.
Fermentation complements glycolysis and makes it possible for ______ to
be continually produced in the __________________________.
By oxidizing the NADH produced in glycolysis, fermentation regenerates
NAD+, which can take part in glycolysis once again to produce more ATP.
There are two pathways that pyruvate can take. One pathway describes plant
fermentation, sometimes called _____________________. The other
pathway describes animal cell fermentation, often called ______________
Alcohol Fermentation
_________________ is the byproduct if oxygen is not present. In addition,
_______________________________ is released.
When yeast and fruit ferments in bread and wine production we utilize this
gas to assist in these industrial processes.
Bread-makers cover the rising dough. The dough rises because of the carbon
dioxide gas creating bubbles.
If your family makes their own beer or wine you have probably seen the
'bubblers' in the large flasks producing carbon dioxide.
Lactic Acid Fermentation
In lactic acid fermentation the pyruvic acid produced at the end of
glycolysis is used to capture the __________________________________.
In the process _________________________ is produced.
Lactic acid shuts down muscle function very quickly. It is the feeling of
muscle soreness after heavy exertion.
After shoveling snow, lifting weights, sprinting, our muscles need to
recover. We can't force enough _______________into those large muscles
to satisfy their needs. Our recovery is called ________________________.
3
Biology 30 - Ch. 6 – Cellular Respiration Notes
Krebs Cycle
• Following the reactions in the _______________ the pyruvic acid stores a
great deal of _________________________________.
• If oxygen becomes present that potential energy can be released during the
aerobic stages of cellular respiration in the ________________________.
These stages are:
• ______________________________________
• ______________________________________
• The pyruvic acid product of glycolysis does not enter directly into the Krebs
cycle.
• It must first be transformed into __________________________________.
• The consequences of this reaction are the production of _________, which
_________________________________________________.
• A _____________molecule is produced, which continues onto the _______
______________________________.
• Because one molecule of glucose produces two molecules of pyruvic acid,
two molecules of __________ are produced per glucose molecule in this
transitional step.
Importance of the Krebs Cycle
• ________________ reacts with __________ to prepare for the Krebs cycle.
• Acetyl CoA is completely broken down into CO2 during the cycle.
• __________________ is made for each acetyl CoA that enters (total _____
per glucose).
• But, most of the electrons have been captured onto ___________________
(per glucose) for the next stage (__________________________).
• The names of the various stages of the Krebs cycle indicate the chemicals
produced...you are not responsible for these.
Electron Transport Chain (ETC)
• The electron transport chain allows the release of the large amount of
chemical energy stored in reduced ___________________ and reduced
_____________________________.
• The energy released is captured in the form of ATP (__________________
________________________________).
• During the previous two stages (Glycolysis, Krebs cycle) several FADH2
and NADH molecules were produced.
4
Biology 30 - Ch. 6 – Cellular Respiration Notes
• The electron transport chain (ETC) consists of a series of molecules, mostly
proteins, embedded in the _________________________________.
• NADH and FADH2 drop off electrons onto a series of molecules in the
mitochondrial inner membrane.
• Greatest amount of ATP is made in this stage (____________ per glucose).
• At the end of the chain ________________combines with the electrons and
removed _________________________________.
• We breathe oxygen therefore to capture the electrons and hydrogen
producing waste water.
Summary of Cellular Respiration
• Glycolysis – ______________________________
• Conversion of pyruvate to acetyl coA – _____________________
• Krebs Cycle – ________________________________.
• ETC – ________________ (NADH produced in the cytoplasm (glycolysis)
produces ________________ by the electron transport system.)
• At the end of the three reactions, Glycolysis has produced ________, Krebs
cycle has produced __________ and the ETC has produced __________.
• Total = ____________ (________________________________________
____________________________________________)
An excellent overview tutorial for cellular respiration can be found at:
http://media.pearsoncmg.com/ph/esm/esm_krogh_biology_3/ch07/animations/chapter_07/Present/Activities/7_2/7_2_1a.swf
5