1. BIOZONE: p. 116-124 due WED 2/4 8.1 Intro to Cellular Respiration
Sponge: Set up Cornell Notes on pg. 71
Topic: 8.1 Intro to Cellular Respiration
Essential Question: How is cellular respiration directly related to photosynthesis?
8.1 Intro to Cellular Respiration
How is cellular respiration directly related to photosynthesis?
Key Vocabulary:
Catabolic pathway
Anabolic pathway
Oxidation
Reduction
Mitochondria
Cellular Respiration
BIOZONE: p due WED 2/4

2. Chemical reactions carried out by an organism
Anabolic pathways: result in the synthesis of more complex molecules from simpler ones
Photosynthesis
Building a sugar molecule
Catabolic pathways: result in the breakdown of complex molecules to smaller molecules
Cellular respiration
Breaking down sugar molecules

3. Two general types of chemical reactions: Oxidation and reduction
Reduction: is the gain of electrons or a decrease in oxidation (reduce) state by a molecule, atom, or ion.
Oxidation:  is the loss of electrons or an increase in oxidation state by a molecule, atom, or ion.
Tree map on P. 70

4. Oxidation vs Reduction – Add to tree map
Loss of Electrons
Gain of Electrons
Gain of Oxygen
Loss of Oxygen
Loss of Hydrogen
Gain in Hydrogen
Results in many C-O (Carbon-oxygen) bonds
Results in many C-H (carbon-hydrogen) bonds
Results in a compound with LOWER potential energy
Results in a compound with HIGHER potential energy

5. Oxidation and reduction P.70
Loss of electrons
Gain of electrons
Gain of Oxygen
Loss of Oxygen
Loss of hydrogen
Gain of hydrogen
Results in many C-O (carbon-oxygen) bonds
Results in many C-H (carbon-hydrogen) bonds
Results in a compound with lower potential energy
Results in a compound with higher energy
These two reactions occur together during chemical reactions
One compound’s or element’s loss is another compound or element’s gain
Because they always occur together, they are considered redox reactions
Plays a key role in the flow of energy through living systems

6. Energy Energy is a topic of discussion every day in our modern world
IB students know what it is like to be tired and need a nap after a long day of school
We talk about being hungry all the time
Cellular respiration allows us to release the chemical energy stored in our food (glucose and other carbohydrates) to fuel all of our life processes.

7. Cellular Respiration
Organic molecules contain energy in their molecular structures
Each covalent bond in glucose, amino acids or fatty acids represents stored chemical energy
When we burn wood in a fire, we are releasing that stored chemical energy in the form of heat and light
Burning is the release of chemical energy called rapid oxidation
This is not controlled by enzymes and results in the breaking of many, many covalent bonds in a very short period of time and thus a nearly uncontrolled energy release

8. Mitochondria
It is inside the mitochondria and in the presence of oxygen that the majority of cellular respiration occurs

9. Mitochondria Supply energy to the cell “POWER HOUSE” of the cell
Convert the molecules you eat into usable energy
Rod shaped organelles that appear throughout the cytoplasm
Their size is close to that of a bacterial cell
Have their own DNA
Contains ribosomes
Double-membrane
Outer membrane is smooth
Inner membrane is folded into cristae
Inside the inner membrane is a semi-fluid called matrix

10. Bottom of P. 70 Mitochondria
Draw and label a diagram showing the structure of a mitochondrion as seen in electron micrographs
Bottom of P. 70

11. Mitochondria
Draw and label a diagram showing the structure of a mitochondrion as seen in electron micrographs
Outer Membrane
Cristae
(crista- singular)
Matrix
Inner Membrane

12. Cellular Respiration
Cellular Respiration: Cells break down (metabolize) their organic nutrients by way of slow oxidation (vs. rapid oxidation in the case of burning wood). The ultimate goal of releasing energy in a controlled way is to trap the released energy in the form of ATP molecules

13. Cellular Respiration
A molecule, such as glucose is acted on by a series of enzymes which catalyze a sequential series of reactions in which the covalent bonds are broken (oxidized) one at a time
As each covalent bond is broken a small amount of energy is released
If a cell does not have glucose available, other organics molecule may be substituted, such as fatty acids or amino acids

14. Cellular Respiration Equation
All organisms need to produce ATP for energy, so all organisms carry out respiration

15. Crash Course: Cellular Respiration (0-4m13s)

16. Sponge: Set up Cornell Notes on pg. 73
Topic: 8.1 Cellular Respiration: Glycolysis & Krebs Cycle
Essential Question: None
8.1 Cellular Respiration: Glycolysis & Krebs Cycle
Key Vocabulary:
Glycolysis
Krebs Cycle
BIOZONE: p due WED 2/4

17. Glycolysis in a nutshell
All cells begin the process of cell respiration of glucose the same way.
Glycolysis:
Glucose enters a cell and floats in the cytoplasm
Enzymes modify the glucose
A series of reactions will split the 6-carbon glucose molecule into two 3- carbon molecules called pyruvate
Energy from the breaking of these bonds was used to form a small amount of ATP
of pyruvate

18. Glycolysis Pyruvate Pyruvate c c c c c c 6-carbon glucose 2 ATP 2 ADP
Fructose-1, 6-biphosphate P P
Glyceraldehyde-3-phosphate (G3P aka triose phosphate)
1 NAD+
1 NAD+
1 NADH
1 NADH P P P P
2 ADP
2ADP
2 ATP
2 ATP
Pyruvate
Pyruvate

19. Glycolysis Glycolysis means "sugar splitting" It uses no oxygen
Occurs in the cytosol (cytoplasm) of the cell
No required organelles
Occurs both in aerobic (oxygen) and anaerobic (no oxygen) environments
Occurs both in prokaryotic and eukaryotic cells

20. Glycolysis: 1 Two molecules of ATP are used to begin glycolysis.
Phosphorylation: The phosphates from the ATPs attach to the glucose to form fructose-1, 6-biphosphate
*Remember when ATP (adenosine triphosphate) loses a phosphate it becomes ADP (adenosine diphosphate)

21. Glycolysis: 2
Lysis “to unbind”: The 6-carbon phosphorylated fructose is split into two 3-carbon sugars called glyceraldehyde-3-phosphate (G3P aka triose phosphate)

22. Glycolysis: 3
Each G3P molecule undergoes oxidation to form a reduced molecule of NAD+ into NADH.
As NADH is being formed, released energy is used to add an inorganic phosphate to the remaining 3- carbon compound

23. Glycolysis: 3
Enzymes then remove the phosphate groups so they can be added to ADP to produce ATP
The end result is the formation of:
4 ATP molecules
2 NADH molecules
2 Pyruvate molecules

24. Krebs Cycle
Once glycolysis has occurred and there is oxygen present, pyruvate enters the matrix of the mitochondria via active transport

25. The Krebs Cycle The Link Reaction o CO² c c c (Occurs in Mitochondria)
Pyruvate
CoA
Acetyl CoA c c c
NAD+
NADH c c c c c c c c c c
Citrate 6c aka Citric acid
The Link Reaction
(occurs in mitochondria)
Oxaloacetate o
CO² c o
NAD+
NADH
NADH
NAD+ c c c c c
FADH₂ o
CO² c o
FAD
NAD+
ATP
NADH
ADP + P i c c c c

26. The Krebs cycle will run twice for each glucose molecule entering cellular respiration
Once for each pyruvate

27. The Link Reaction
Each pyruvate is decarboxylated when it loses a carbon dioxide molecule (released as a waste gas)
The acetyl group is then oxidized with the formation of reduced NAD+
The acetyl group combines with coenzyme A and becomes known as acetyl-Coenzyme A (uh-C-tyl)

28. 1.
Acetyl CoA combines with a 4-carbon compound called oxaloacetate (oxa-lo-ass-itate)
The result is a 6-carbon compound known as citric acid

29. 2.
Citrate (6-carbon compound) is oxidized (H+ lost) to form a 5-carbon compound
Decarboxylation: Carbon is released from the cell as CO²
While the 6-carbon compound is oxidized, NAD+ is reduced to form NADH (H+ added)

30. 3.
The 5-carbon compound is oxidized (H+ lost) to form a 4-carbon compound
Decarboxylation: another carbon is released from the cell as CO²
Another NAD+ is reduced to form NADH (H+ added)

31. 4.
The 4-carbon compound undergoes various changes resulting in several products:
NAD reduced (H+) to NADH
Coenzyme FAD reduced (H+) to form FADH₂
Phosphorylation: reduction of an ADP to form ATP

32. 5.
The 4-carbon compound is changed during step 4 to re-form the starting compound of the cycle, oxaloacetate
The oxaloacetate may then begin the cycle again!

33. PRODUCTS OF THE KREBS CYCLE
2 ATP molecules
6 molecules of NADH (allow energy storage and transfer)
2 molecules of FADH₂
4 molecules of carbon dioxide (released)
****REMEMBER: The cycle rotates twice!!!!!!
So far, only 4 ATPs have been gained (6 generated, but it “costs” two to start glycolysis)

34. Crash Course: Cellular Respiration (4m13s-11m3s)

35. BIOZONE: p. 116-124 due TOMORROW
Sponge: Set up Cornell Notes on pg. 75
Topic: 8.1 Cellular Respiration: ETC
Essential Question: Compare the ETC to the photosystems (II/I) in photosynthesis.
8.1 Cellular Respiration: ETC
Compare the ETC to the photosystems (II/I) in photosynthesis.
Key Vocabulary:
Oxidative Phosphorylation
BIOZONE: p due TOMORROW

36. Oxidative Phosphorylation: ETC/ ATP synthase

37. Oxidative Phosphorylation: ETC/ ATP synthase
The ETC is where most of the ATPs from glucose break down are produced
It is the first stage of CR where O² is actually needed
Occurs on the inner mitochondrial membrane and on the membrane of the cristae
In this chain, electrons pass from one carrier to another because the receiving molecule has a higher electronegativity (therefore a stronger attraction) for electrons
The source of the electrons are the coenzymes NADH and FADH₂ from the Krebs Cycle

38. Oxidative Phosphorylation: ETC/ ATP synthase
Cyt∙c Q
FMN
Fe∙S

39. Electron Transport Chain
Oxidative Phosphorylation 1.
Proteins inside the inner membrane of the mitochondria take high energy electrons from NADH and FADH₂
NADH is oxidized to become
NAD H e-
Electrons enter the ETC into the FMN protein
FADH₂ is oxidized to become:
FAD H e-
Electrons enter the ETC into the Fe∙S protein
Electrons will continue on to the Q electron carrier (not a protein) which will take them to the next protein in the chain

40. Electron Transport Chain2.
High energy electrons travel through the proteins in the ETC losing energy at each protein
The proteins use energy from the electrons as they are de- energized to pump the hydrogen ions across the inner membrane to produce a chemiosmotic gradient
The hydrogen ions build up on the inside of the inner membrane
Inside of membrane

41. Electron Transport Chain3.
Oxygen enters the cellular respiration process as the final electron acceptor in the ETC
Water of metabolism: The O² picks up electrons and 2 H+ (from the aqueous surroundings of the matrix) to form water
The H²O molecules are given off as a waste product

42. ATP Synthase 4. Energy is now available as a result of the ETC
Chemiosmosis: H+ diffuse through the protein channel of the ATP synthase back into the matrix
As H+ move through ATP synthase, the enzymes harness the available energy allowing the phosphorylation of ADP to ATP (adding of phosphates)

43. Products of Oxidative Phosphorylation
32 ATP (approx.)

44. Cellular Respiration Overview
The Reactants of Cellular Respiration
Glucose (from Photosynthesis) O² 2 2 6
The Products of Cellular Respiration
CO²
H²O
36 ATP (approx.) 32 6 6

45. Cellular Respiration Overview
Process
ATP used
ATP produced
Net ATP gain
Glycolysis 2 4
Krebs Cycle
ETC/ chemiosmosis 32
TOTAL 38 36 2 2 6 32 6 6

46. Cellular Respiration Overview
Theoretically 36 ATPs are produced by CR, but in reality the # is closer to 30
This is thought to be due to some H+ moving back to the matrix WITHOUT going through the ATP synthase
The 30 ATPs generated by CR account for approx 30% of the energy present in the chemical bonds of glucose
The remainder of the energy is lost from the cell as heat
Process
ATP used
ATP produced
Net ATP gain
Glycolysis 2 4
Krebs Cycle
ETC/ chemiosmosis 32
TOTAL 38 36

47. The products of cellular respiration are the reactants of photosynthesis
The reactants of cellular respiration are the products of photosynthesis

48. Crash Course: Cellular Respiration (11m-13m25s)

49. 8.1 Other Aspects of Cellular Respiration
Sponge: Set up Cornell Notes on pg. 77
Topic: 8.1 Other Aspects of Cellular Respiration
Essential Question:
8.1 Other Aspects of Cellular Respiration
Key Vocabulary:
Electromagnetic spectrum
Action spectrum

50. Alcoholic Fermentation
P. 76
Lactic Acid Fermentation

51. The mitochondria and cellular respiration
In biology, the relationship between structure and function is a universal theme
Chloroplast Structure
Function Allowed
Separates the contents of the mitochondrion from the rest of the cell
Outer mitochondrial membrane
Internal semi-fluid that contains the enzymes for the link reaction in the Krebs cycle
Matrix
Increase surface area for oxidative phosphorylation (ETC/ATP synthase)
Cristae
Inner mitochondrial membrane
Contains the protein carriers for the ETC and ATP synthase for chemiosmosis
Reservoir for hydrogen ions (protons), the high concentration of hydrogen ions is necessary for chemiosmosis
Space between inner and outer membranes

52. Anaerobic Respiration
All pathways of cellular respiration start with glycolysis
If an organism derives their ATP completely without the use of oxygen they are referred to as anaerobic
This is known as fermentation
Draw a small picture on p. 77

53. Anaerobic Respiration

54. Fermentation There are two main anaerobic pathways:
Alcoholic fermentation
Lactic acid fermentation

55. Alcoholic Fermentation
Glycolysis occurs first (net gain 2 ATP- 2 pyruvate)
Yeast will convert both the 3-carbon pyruvates into molecules of ethanol
Ethanol is a 2-carbon molecule, so a carbon atom is “lost” in this conversion
The “lost” carbon atom is given off as a CO² molecule
Both ethanol and CO² that are produces are waste products to the yeast and are simply given off to the environment

56. Alcoholic Fermentation
Draw on top of
p. 76
Ethanol
glycolysis
Ethanol

57. Ex:
Yeast is added to baker’s bread as the generation of CO² molecules helps the dough rise
It is also common to use yeast in the production of ethanol as drinking alcohol

58. Alcoholic Fermentation

59. Lactic Acid Fermentation
Organisms that use an aerobic cell respiration pathway sometimes find themselves in a metabolic situation where they cannot supply enough oxygen to their cells

60. Lactic Acid Fermentation
Ex: A person pushing beyond their normal exercise pattern or routine
In this situation, the person’s pulmonary and cardiovascular systems (lungs and heart) supply as much oxygen to their cells as is physically possible
If a person’s exercise exceeds their capacity of supplying oxygen, then at least some of the glucose entering into cellular respiration will follow the anaerobic pathways called lactic acid fermentation

61. Lactic Acid Fermentation
Glycolysis first (net gain 2 ATP- 2 pyruvate)
In a low-oxygen situation excess pyruvate molecules are converted into lactic acid molecules
Lactic acid molecules are 3-carbon molecules (so there is no production of CO²)

62. Lactic Acid Fermentation
What benefit then?
It allows glycolysis to continue with the small gain of ATP generated in addition to the ATP which is already being generated through the aerobic pathway

63. Lactic Acid Fermentation
Draw on bottom of
p. 76
Lactate
glycolysis
Reaction reversible with O² present
Lactate

64. Lactic acid fermentation is used in food production using bacteria:
yogurt
cheese
Turns soy beans into soy sauce
Turns cabbage into sauerkraut

65. Aerobic Cell Respiration is the most Efficient!!!