Chapter 8 Cellular Respiration
Cellular respiration includes the anaerobic processes of glycolysis and fermentation as well as aerobic respiration that occurs in mitochondria. The concept of the metabolic pool is also discussed.
Respiration
is about breathing, yes, but physiologically why do you need to breathe?
The answer lies in an understanding of the role of the
respiratory gases CO2
and O2.
Each organism “breathes” that is exchanges those respiratory
gases with its environment. For
terrestrial animals the exchange occurs between some body organ
(lungs-humans; skin-earthworms) and the atmosphere.
For some aquatic animals the exchange occurs between an aquatic
environment and the body surface. For example, all parts of a jellyfish’s
exposed body takes in O2 and releases CO2 .
For other aquatic animals (e.g. bony fish such as bass)
specialized body surfaces called gills are the sites of gas exchange.
Gills with their greater efficiency in exchanging respiratory
gases are required in order to meet the metabolic needs of the fish
whereas in jellyfish no specialized respiratory organ is needed to meet
the needs of the lowly jellyfish.
As you learn the chemistry of cellular respiration, keep in mind these
questions: “Why do we need O2 or what happens to the O2
once it enters your body?” and “Where in our body’s physiology
does the CO2 we exhale come from?”
The purpose of cellular respiration is however not to intake O2
and release CO2. Those
events are necessary sideline events supporting the main goal of ATP
production. You will learn
that glucose is the fuel broken down producing 36 molecules of ATP for
every single glucose molecule processed.
FEELING THE BURN
________________________ occurs when oxygen reaches cells to support energy needs.
________________________ occurs when the demand for oxygen outstrips the body's ability to deliver it.
Without enough oxygen, muscle cells break down glucose to produce ___________________.
If too much lactic acid builds up, your muscles _______________________.
_______________________ allows your body to adapt to increased activity.
ENERGY FLOW AND CHEMICAL CYCLING IN THE BIOSPHERE
Fuel molecules in food represent _______________________.
Animals depend on plants to convert solar energy to _________________________. This chemical energy is in the form of ________________________________.
I. Producers and Consumers
Photosynthesis:
1. _____________________________
2. _____________________________
Autotrophs:
1. _____________________________
2. _____________________________
Heterotrophs:
1. _____________________________
2. _____________________________
Producers:
1. _____________________________
2. _____________________________
Consumers:
1. _____________________________
2. _____________________________
II. Chemical Cycling between Photosynthesis and Cellular Respiration
The ingredients for photosynthesis are _______________________________________________.
Carbon dioxide is obtained from____________________________________________________.
Water is obtained from ___________________________________________________________.
________________________ rearrange the atoms of these ingredients to produce ____________________ and other _______________.
________________________ is a by-product of photosynthesis.
Both plants and animals perform _______________________________.
The waste products of cellular respiration _________________________________ , are used in photosynthesis.
CELLULAR RESPIRATION: AEROBIC HARVEST OF FOOD ENERGY
Cellular respiration:
1. _________________________________
2. _________________________________
I. The Relationship between Cellular Respiration and Breathing
Cellular respiration requires a cell ______________________________________________.
Breathing ________________________________________________________________.
II. The Overall Equation for Cellular Respiration
A common fuel molecule for cellular respiration is _______________________.
The overall equation for what happens to glucose during cellular respiration:
_________________________________________________________
III. The Role of Oxygen in Cellular Respiration
During cell respiration __________________ and its _________________ change partners.
Hydrogen and its electrons go from ___________ to ______________ , forming _______________.
A. Redox Reactions
Chemical reactions that transfer electrons from one substance to another are called ___________________________________.
The loss of electrons during a redox reaction is called ______________________________.
The acceptance of electrons during a redox reaction is called ________________________.
Why does electron transfer to oxygen release energy?
1. _________________________________________________
2. _________________________________________________
B. NADH and Electron Transport Chains
The first step is an electron acceptor called ____________________
The rest of the path consists of an electron transport chain:
1. ____________________________________________________
2. ____________________________________________________
IV. The Metabolic Pathway of Cellular Respiration
Cellular respiration is an example of a _________________________________.
A metabolic pathway is a ___________________________________________.
All of the reactions involved in cellular respiration can be grouped into three main stages:
1. _____________________
2. _____________________
3. _____________________
A. A Road Map for Cellular Respiration
The path of glucose through cellular respiration:
___________________________________________________________________________________________
B. Stage 1: Glycolysis
A molecule of glucose is split into two molecules of _________________________.
Glycolysis breaks a ____________________________ into two __________________________________.
These molecules then donate high energy electrons to _____________ , forming ______________________.
Glycolysis makes some ___________ directly when enzymes transfer ___________________ groups from fuel molecules to ________.
Glycolysis animation: http://www.science.smith.edu/departments/Biology/Bio231/glycolysis.html
Glycolysis animation: http://programs.northlandcollege.edu/biology/Biology1111/animations/glycolysis.html
C. Stage 2: The Citric Acid Cycle
The citric acid cycle completes the breakdown of __________________.
In the citric acid cycle, ______________ from glycolysis is first "prepped" into a usable form, ________________________.
The citric acid cycle extracts the energy of sugar by breaking the _________________ molecules all the way to ____________.
The cycle uses some of the energy to form ____________.
The cycle also forms ____________________________.
Citric Acid Cycle animation: http://www.science.smith.edu/departments/Biology/Bio231/krebs.html
Citric Acid Cycle animation: http://www.wiley.com/legacy/college/boyer/0470003790/animations/tca/tca.htm
D. Stage 3: Electron Transport
Electron transport releases the ________________ your cells need to make most of their ____________.
The molecules of electron transport chains are built into the inner membranes of the ___________________________.
The chain functions as a chemical machine that uses energy released by the "fall" of electrons to pump __________________ across the inner membrane of the mitochondria. These ions store ________________________________.
When the hydrogen ions flow back across the membrane, they release ______________________.
The ions flow through _____________________________.
ATP synthase takes the energy from this flow to synthesize ___________________.
Electron Transport System animation: http://www.science.smith.edu/departments/Biology/Bio231/etc.html
ETS animation: http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter9/animations.html#
E. The Versatilty of Cellular Respiration
Cellular respiration can "burn" other kinds of molecules besides glucose:
1. ______________________________
2. ______________________________
3. ______________________________
F. Adding Up the ATP from Cellular Respiration
The amount of ATP generated from each stage of cellular respiration:
_________________________________________________________________________________________________________
FERMENTATION: ANAEROBIC HARVEST OF FOOD ENERGY
Some of your cells can actually work for short periods of time without ______________________.
Fermentation:
____________________________________________
I. Fermentation in Human Muscle Cells
_________________________ is the metabolic pathway that provides ATP during fermentation:
1. __________________________________________________
2. __________________________________________________
A. Fermentation in Microorganisms
Various types of microorganisms perform fermentation:
1. _____________________________________________________
2. _____________________________________________________
Food industry uses _______________ to produce various food products.
Evolution Connection: Life on an Anaerobic Earth
Ancient _________________ probably used glycolysis to make ATP long before _________________ was present in Earth's atmosphere.
Glycolysis is the metabolic heirloom from earliest cells that continues to function today in the ____________________________________.
Cell respiration outline: http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/CellularRespiration.html
Cell respiration animation: http://scholar.hw.ac.uk/site/biology/activity3.asp?outline=
Cell respiration animation: http://www.sp.uconn.edu/~terry/Common/respiration.html
Cell respiration quiz: http://scholar.hw.ac.uk/site/biology/topic3.asp?outline=
For a very good tutorial on Cell respiration, click on http://www.biosci.uga.edu/metabolism/overview1.html You can print the study guide below to assist you in completing this tutorial.
INTERNET ACTIVITY – CELLULAR RESPIRATION
Read the introduction. Click "Next" at bottom of page or page 2 at the top right.
1. Read the overview for respiration. What are the required reactants of the process? What are the products?
Click "Next" or page 3. Study the legend. It will help you through this tutorial. Click "next" or choose "glycolysis" on the menu on the left.
2. What is the first stage of respiration? Summarize the process. Be sure to play the animation.
3. Click ‘next" or go to page 2. What materials must be present for glycolysis to succeed?
4. Click "next" or go to page 3. Play the animation. Describe the first energy investment by the cell. What is ultimately produced following this step?
5. Click "next" or go to page 4. Play the animation. Is energy gained or lost in this stage? (circle the answer)
6. Click "next" or go to page 5. Play the animation. Read the description of the third phase. Recall that 2 ATP were used in the first step (glycolysis). Explain then how ATP can be produced in this step if two are used up in the first step.
7. Click "next" or go to page 6. Play the animation. What are the ultimate final products of glycolysis? Click "Checkpoint Charlie". Answer the question until you get the correct answer. Write your answer here.
8. Click "next" or choose "Krebs cycle" from menu at left. The Krebs cycle (second phase of respiration) does not produce large quantities of ATP. Why is it important then?
9. Click "next" or choose page 2. Where does the Krebs cycle take place? Where does the electron transport phosphorylation (system – ETS) take place?
10. Describe mitochondria.
11. Click "next" or choose page 3. Study the diagram. What are the four products of the Krebs cycle?
Click "next" or choose page 4. Play the animation. Read the events description.
12. Click "next" or go to page 5. Explain why Krebs is a cycle.
13. Click "next" or go to page 6. What are the most important products of Krebs? Why?
14. Click "next" or go to page 7. Read the summary. Click on "Check point Charlie". Answer all three questions. Write the correct answers below.
15. Select Electron Transport Chain from the menu at left. Note: Electron Transport Phosphorylation will be abbreviated as ETP. What are the products of ETP?
Click "next" or go to page 2. Play the animation and read the description.
Click "next" or go to page 3. Play the animation and read the description.
16. Click "next" or go to page 4. Play the animation and read description. Describe the gradient which forms.
17. Click "next" or go to page 5. Play the animation and read description. What is the final carrier in this chain of electrons? What is produced as a result?
18. Click "next" or go to page 6. What is the final stage of respiration? (Where ATP is produced in mass quantities).
Click "next" or go to page 7. Observe the diagram. Read the description.
19. Click "next" or go to page 8. Play the animation. Read the description. Summarize the process of Chemiosmosis.
20. Click "next" or go to page 9. Read the summary. Click "checkpoint Charlie". Answer all three questions. Write the answers below.
21. Briefly scroll through the anaerobic respiration sections and animations. Does oxygen have to be present for some organisms to produce energy? Expalin.
22. Select "Test your Knowledge" from the menu. Play Powermatch and Power source. Remember that difficult activities require different energy processes in your cells.
23. Find a picture (with a cut-away view) of mitochondria. Sketch and label the structure in the space below. In what types of organisms would you expect to find such structures? Why?