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CELLULAR RESPIRATIONPages 228 - 237
CELLULAR RESPIRATION
1. All organisms respire!2. Cellular respiration is like the
reverse reaction of photosynthesis – Products of photosynthesis become the
reactants of cellular respiration– Respiration breaks down glucose (Catabolic
Rxn.)3. ATP energy is released
– ATP is used for cellular processes like movement of materials, cellular reproduction, protein synthesis, etc.
Overview of Respiration
Glucose
CELLULAR RESPIRATION
4. What Organelle is involved in cellular respiration?
MITOCHONDRIAMITOCHONDRIA
Overview of Respiration
CELLULAR RESPIRATION
Two Types of Cellular Respiration:
1. Aerobic (Requires Oxygen)2. Anaerobic (No oxygen
required)
Overview of Respiration
CELLULAR RESPIRATION
C6H12O6 + 6O2 6CO2 + 6H2O + Energy
Ok! Lets look at our Reactants!1) Glucose2) Oxygen
Wait! You just told me there is a process that does not reqire oxygen??
Overview of Respiration(Aerobic)
• This is where it gets confusing……
• For the purposes of this class, we are going to focus on regular cellular respiration which is aerobic (requires oxygen).
• However, keep in mind that some simple organisms can only do anaerobic (no oxygen required) cellular respiration.
Where do the reactants come from?
Glucose - made during Photosynthesis.
Oxygen - is in the air.
CELLULAR RESPIRATION
• The formula for aerobic cellular respiration is
C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (ATP)
• The “word” equation for this is:
Cellular RespirationAEROBIC
RESPIRATION
• Aerobic cellular respiration has 3 stages.
1.Glycolysis
2.Krebs cycle
3.Electron Transport Chain, or ETC
Cellular RespirationAEROBIC RESPIRATION
Glucose is Broken Down•Inputs:
– 1 Glucose– 2 ATP
• Outputs:– 2 Pyruvate – 2 NADH– 2 ATP Net (4 ATP made but 2 used = 2 left)
Occurs in the CYTOPLASM
Step 1: GLYCOLYSIS
Step 1: GLYCOLYSIS
Per 1 molecule of glucose and 2 molecules of ATP, how many….
Net # of ATP made?NADPH made?Pyruvate made?
Where does pyruvate come from?
Where does glycolysis take place?
AEROBIC RESPIRATION
• The step in which pyruvate is broken down • Inputs:
– 2 Pyruvate
• Outputs:– 2 ATP– 8 NADH– 2 FADH2
– 6 CO2
• Occurs in the mitochondria
Step 2: KREB’S CYCLE
AEROBIC RESPIRATION
Step 2: KREB’S CYCLE
Step 3: ELECTRON TRANSPORT
CHAIN• In this step, the breakdown of Glucose is completed.
• Inputs:– 8 NADH– 2 FADH2
– 6 O2
• Outputs:– 32 ATP– 6 H2O
• Occurs in the mitochondria
Step 3: ELECTRON TRANSPORT
CHAIN
• The mitochondrial electron transport chain is similar to that used in chloroplasts for photosynthesis. NADH and FADH2 molecules formed during Glycolysis and Krebs Cycle carry their electrons to the electron transport chain. The electron transport chain creates a proton gradient that ultimately leads to the production of a large amount of ATP.
Animation
WOW! MY BRAIN HURTS!
Maybe a Video Will Help
http://www.youtube.com/watch?v=00jbG_cfGuQ
Summary of Aerobic Respiration
• Glycolysis breaks down glucose into pyruvate. 2 ATP Made
• Pyruvate is further broken down in the Kreb’s Cycle. 2 ATP Made
• The electron transport chain finishes breaking down glucose and makes 32 ATP
• CO2 and Water are wastes (or byproducts).
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
36 ATP MADE TOTAL
Cellular Respiration
2 36
Where does Glycolysis take place?
Glycolysis
What does Glycolysis require?
What is step 2 of cellular respiration?
Glycolysis
Where does the Krebs Cycle take place?
Glycolysis
What does the Krebs Cycle Make?
What does the ETC Use?
What does the ETC Make?
ANAEROBIC RESPIRATIONCellular respiration when oxygen is NOT present is called
ANAEROBIC- NO OXYGEN!!
• Some cells can function for a little while without oxygen.
• Other Cells may go their entire life without oxygen.
But they still need ENERGY!!
CELLULAR RESPIRATION
•Can release energy when oxygen is not present but...
•It’s far less efficient.•Begins with glycolysis followed by fermentation.
ANAEROBIC RESPIRATION
Same as Before: Glucose is Broken Down•Inputs:
– Glucose– 2 ATP
• Outputs:– 2 Pyruvate – 2 NADH– 4 ATP
Occurs in the CYTOPLASM
Step 1: GLYCOLYSIS
Special Note: Glycolysis can produce
thousands of ATP molecules in milliseconds.But quickly fills all available NAD+ (electron carriers) with electrons and the process stops, so it’s only good for short-term energy.
ANAEROBIC RESPIRATION
1.Type of anaerobic respiration that releases energy without oxygen
2.If oxygen is not present, the next step is eithera. Lactic acid fermentationb. Alcoholic fermentation
Step 2: FERMENTATION
ANAEROBIC RESPIRATION
Lactic Acid Fermentation– Converts pyruvic acid into
lactic acid and CO2
– Responsible for food production using microbes (Swiss cheese)
– Causes muscle fatigue/burning
Step 2: FERMENTATION
ANAEROBIC RESPIRATION
Alcoholic Fermentation– Converts pyruvic acid into
alcohol and CO2
– Responsible for food production using microbes (sourdough bread)
Step 2: FERMENTATION
02+ C6H12O6 6CO2 + 6H2O + ATP + alcohol
or lactic acid
Summary Of Fermentation
Glycolysis Fermentation
Advantage of Aerobic Respiration
Yields 66% more energy
36 net ATPThat’s nearly 20 times more ATP than
glycolysis alone.
Energy Yield without oxygen
Glycolysis 4 ATP (gross)Fermentation+ 2 ATP 6 ATP
But 2 ATP go back into glycolysis as the energy to start the reaction, so there is only 4 net ATP from anaerobic respiration!!! (32 less than aerobic)
A. to make ATP
B. to process H2O
C. to store glucose
D. to deliver oxygen
What is the overall purpose of cellular respiration?
Cellular Energy
8.3 Formative Questions
Chapter 8
Which represents the general sequence of cellular respiration?
Cellular Energy
A. TCA cycle chemiosmosis glycolysis
B. glycolysis Krebs cycle electron transport
fermentation
D. aerobic pathway anaerobic pathway
8.3 Formative Questions
C. electron absorption catalysisphosphorylation
Chapter 8
A. glycolysis
B. Krebs cycle
C. electron transport
Which stage of cellular respiration is the anaerobic process?
Cellular Energy
8.3 Formative Questions
Chapter 8
A. CoA
B. CO2
C. FADH2
D. NADH
Which molecule generated by the Krebs cycle is a waste product?
Cellular Energy
8.3 Formative Questions
Chapter 8
What prevents pyruvate from entering the Krebs cycle and instead results in this pathway?
Cellular Energy
A. a buildup of CO2
B. a lack of oxygen
Standardized Test Practice
Chapter 8
C. an excess of glucose
D. an increaseddemand for ATP
