1. Cellular Metabolism: Photosynthesis and Cellular Respiration
Chapters 8-9

2. What is the ultimate purpose of nutrition?
To obtain energy
We use this energy for:
to fuel life processes
Getting ATP out of glucose
is called____________ and
it occurs in the ________ of
Eukaryotes.

3. How do organisms get nutrition?
Autotrophs or producers obtain glucose
by producing it. Photosynthesis converts light energy into food energy.
Examples of organisms: Cyanobacteria (blue-green algae), plants, protists,
Heterotrophs or consumers obtain food/glucose by consumer other organisms.
Examples- Animals

6. Venus Flytraps – missing some important amino acids so they get it from insects.

9. The chemical reaction for Photosynthesis is:
sunlight
Water + Carbon Dioxide > Glucose + Oxygen
6H2O + 6CO > C6H12O6+ 6O2
The chemical reaction for Cellular Respiration is:
Glucose + Oxygen  Carbon Dioxide + Water
Energy
C6H12O6  +  6O2    6CO2  +  6 H2O 
  36 ATP

10. ATP-Adenosine TriphosphateATP the most important energy-containing compound in biological systems.
The energy from ATP can be used for :
mechanical functions ____________________________________________________________
active transport ____________________________________________________________
chemical reactions necessary for life ______________________________
____________________________________________________________

13. More than 10 million new ATP molecules are produced per second in cells. Muscle and nerve cells produce even more!
An ATP molecule releases energy whenever ……
…….last phosphate bond is broken

14. Cellular Respiration: The Use of Food Energy to make ATP
The process by which chemical energy stored in food is used to form ATP to fuel life processes.
The balanced equation for cellular respiration:
C6H12O6  +  6O2    6CO2  +  6 H2O 
  36 ATP
What types of organisms conduct cellular respiration? ALL living organisms ALL OF THE TIME.

17. 1st – we will discuss photosynthesis (producers only)
2nd – we will discuss cellular respiration (ALL organisms – producers, consumers, decomposers)

18. Chloroplast Organelle where photosynthesis takes place. Stroma
Outer Membrane
Thylakoid
Granum
Inner Membrane
Thylakoid stacks are connected together

19. The two chemical reactions of photosynthesis are localized:
Photosynthesis - 2 stages
Light Dependent Reactions
Light Independent Reactions (used to be called dark reactions)
The two chemical reactions of photosynthesis are localized:
light-dependent reactions- occurs on the thylakoid membranes of the chloroplast
light-independent reactions - occurs in the surrounding stroma

20. Two Groups of Reactions
Light-dependent reactions
Chlorophyll and other molecules of the thylakoids trap sunlight energy
Sunlight energy is converted to the energy carrier molecules ATP and NADPH
Water molecule is split and Oxygen gas is released as a by-product

21. Two Groups of Reactions
Light-independent reactions
Enzymes in the stroma synthesize glucose and other organic molecules using the chemical energy stored in ATP and NADPH
Inorganic CO2 gets converted to glucose C6H12O6 Organic

22. Pigments:
The color of an object is the color of the light that it _____________________.
There are different types of pigments that can be used in photosynthesis:
The most important is Chlorophyll -blue/green in color-it absorbs mainly red and blue wavelengths of light
Others include:
Carotene-orange color
Xanthophyll-yellow color
These pigments are seen in the fall when the main pigments are moved to the roots of the plant

23. The Big Picture of Photosynthesis
Light “Dependent” Reactions
Light sends electrons in the thylakoid to a high energy state
Water is split to replace electrons and oxygen is formed
Light “Independent” Reactions
ATP used to convert
6 carbon dioxide molecules into glucose

24. Balanced Equation for Photosynthesis
sunlight
6H2O + 6CO > C6H12O6+ 6O2
How many molecules of CO2 are used to make one glucose molecule? ____
How many molecules of H2O must be split to make one molecule of glucose?____
How many molecules of oxygen (O2) are formed in the equation? _____
Like cellular respiration, photosynthesis is a series of chemical reactions called a series
of reactions that together are called a biochemical pathway

25. WHAT DO PLANTS USE GLUCOSE FOR?
1) Cellular Respiration
2) stored as starch
3) forms cell wall (cellulose)

26. WHAT DO ANIMALS USE GLUCOSE FOR?
1)_Cellular respiration
2) stored as glycogen
3)energy is used to build other compounds like proteins, lipids and nucleic acids.

27. Cellular Respiration is also more complex than one simple reaction
Cellular Respiration is also more complex than one simple reaction. It occurs in 3 stages.
1. glycolysis
2. kreb cycle
3. electron transport chain
…assuming there is oxygen for aerobic cellular respiration.

28. Cellular respiration is not one single reaction
Cellular respiration is not one single reaction. Instead it is a series of reactions that together are called a biochemical pathway.
All types of organic compounds including carbohydrates, lipids and proteins can be used at points along the biochemical pathway in order to form ATP.

29. copyright cmassengale
1. Glycolysis
C-C-C-C-C-C
C-C-C
Glucose (6C)
2 ATP used
4 ATP produced
NET – 2 ATP produced
2ATP
2ADP + P
copyright cmassengale

30. copyright cmassengale
2. Krebs Cycle (Citric Acid Cycle) (actually an intermediate step before this (3 C  2 C)
Krebs
Cycle
1 Acetyl CoA (2C)
3 NAD+
3 NADH
FAD
FADH2
ATP
ADP + P
(one turn)
OAA (4C)
Citrate (6C)
2 CO2
copyright cmassengale

31. copyright cmassengale
3. ETC - Electron Transport Chain and Oxidative Phosphorylation (Chemiosmosis for NADH)
NADH
+ H+
ATP
Synthase
1H+
2H+
3H+
higher H+
concentration H+
ADP +
lower H+
(Proton Pumping) P E T C
NAD+
2H+ + 1/2O2
H2O
Intermembrane Space
Matrix
Inner
Mitochondrial
Membrane
copyright cmassengale

32. FIGURE 8-1 A summary of glucose metabolism

33. Overview of Glucose Breakdown
If oxygen is absent fermentation occurs
pyruvate is converted into either lactate, or into ethanol and CO2
If oxygen is present cellular respiration occurs

34. Overview of Glucose Breakdown
The main stages of glucose metabolism are:
Glycolysis
Cellular respiration (if oxygen is present then the products of glycolysis go to the mitochondria and kreb cycle and electron transport chain (ETC) occurs producing a lot of ATP – most of the ATP is made during the ETC )
If no oxygen is present then anaerobic respiration takes place - fementation

35. Anaereobic Respiration or Fermentation: Production of ATP in the absence of Oxygen

36. Two Types of Cellular Respiration
Respiration using oxygen: Aerobic Cellular Respiration
Found in : most plants and animals
Respiration without oxygen: Anaerobic cellular respiration
Found in : unicellular organisms (bacteria yeast) -possible in plants and animals-human muscles too

38. Alcohol fermentation
glycolysis produces 2 ATPs and fermentation produces alcohol and carbon dioxide
Glycolysis is the first step:
chemical equation:
Heat Heat
C6H12O  2C3H4O3 ---- Ethanol + CO2
Certain bacteria and yeasts undergo alcohol fermentation when oxygen is in short supply. We use yeast and alcohol fermentation to brew beer.

39. Alcoholic Fermentation produces alcohol and CO2

41. Energy difference between the two types of respiration about 34 ATPs!
Aerobic Cellular Respiration = 36 ATPs!!!
Anaerobic Cellular Respiration =2 ATPs!!!
Which is more effictive?_____________

42. Stages in Aerobic Cellular Respiration:
A. Glycolysis:
Glycolysis means to split glucose: glyco- (glucose) + –lysis (to split).
Glycolysis takes place in the cytoplasm
During glycolysis: glucose is split into 2 molecules of pyruvic acid.
Pyruvic acid is 3-carbon molecule.
The equation for glycolysis:
C6H12O6  2C3H4O3

44. B. Aerobic Cellular Respiration to Form ATP :
Aerobic Cellular Respiration takes place in the _mitochondria
During Aerobic Cellular Respiration: pyruvic acid molecules are split further to form a total of 34 ATP per glucose molecule.

45. The Big Picture of Aerobic Cellular Respiration
1) Reactions in Glycolysis occur in the cytoplasm
Additional Reactions needed to form ATP:
Krebs Cycle – 2 ATPs
Electron Transport Chain – 32 ATPs!!!
3) These additional reactions occur in: mitochondria

49. Efficiency of aerobic cellular respiration:
60% of energy from food is converted into ATP
Think back to cellular transport:
If a cell has to use active transport to bring a molecule of glucose into the cell for cellular respiration, is it worth it for the amount of energy the cell gets from the molecule of glucose?
Yes, 1 ATP molecule used to bring 1 molecule of glucose into the cell
1 molecule of glucose can produce about 36 ATP

51. Plant that beer is made from

54. Lactic acid fermentation
glycolysis produces 2ATPs
and lactic acid
Glycolysis is the first step
chemical equation:
Heat Heat
C6H12O6 --- 2C3H4O3 --- Lactic Acid
Lactic acid fermentation occurs in bacteria, fungi and even human muscles.

55. Feel the Burn! No Pain No GAIN!!
What causes the “muscle burn” after extreme workouts?
Not enough oxygen gets to your muscles as you are working out, so ATP is produced via lactic acid fermentation.
The Lactic Acid build up in your muscles causes the burning sensation.