Transcript Intro to Cellular Respiration Part II

Intro to Cellular Respiration
Part II:
3 Parts of Cellular Respiration
A.P. Bio Ch. 9
Status Check
• What is an Oxidation-Reduction reaction?
• Which atom is oxidized?
• Which atom is reduced?
Remember
Mufasa!!!!
Big Ideas for Cell. Res.
• Cell. Respiration is a REDOX reaction!!!!!!
• Break EVERY bond in glucose to release energy
(stripping a car)
• Purpose is to transfer energy from glucose to
ATP (atom bomb to sticks of dynamite)
• What is going in and going out at each step,
and why each item is important
Chemical Reaction
C6H12O6 + 6 O2  6 CO2 + 6 H2O +
Energy
• What is being oxidized?
• What is being reduced?
• Key Concepts:
– C in glucose turned into CO2
– O2 converted into H2O
Car Analogy
• Stripping a car
– You want to strip the car
as much as you can in
order to maximize what
you can sell (more $$$$
for more parts)
• For glucose, you want
to break EVERY bond
that you can
– Maximize amount of
energy that you release
and convert to ATP
3 Main Steps for Cell. Res.
• Step 1: Glycolysis
– Split 1 glucose molecule into 2 molecules of
pyruvate
– 1 6-carbon ring  2 3-carbon chains
3 Main Steps for Cell. Res.
• Step 2: Krebs Cycle/Citric Acid Cycle
– Break pyruvate up into CO2, H+, and e– H+ & e- go to Electron Transport Chain (step 3)
3 Main Steps for Cell. Res.
• Step 3: Oxidative
Phosphorylation/Electro
n Transport Chain
– Directs stripped H+ to
diffuse through
membrane proteins in
mitochondria
– As H+ diffuse through,
majority of ATP is created
Before We Begin…
• Nicotinamide (NAD+)
– Serves as a safe e- transporter and H+ transporter
– Created in Glycolysis and CAC
– Used in Oxydative Phosphorylation/ETC
• Flavin adenine dinucleotide (FAD)
– Used like NAD+
– Lower in energy than NAD+
Overview of All 3 Steps
Step 1: Glycolysis
• Split 1 glucose into 2 pyruvate molecules
(yank out the engine and rims)
– Need to actually use energy to start rxn (2 ATP)
– Split releases energy (ATP), e- and H+ (NADH)
– Split creates pyruvate, 4 ATP, 2 NADH, and 2 H2O
Step 1: Glycolysis
• In your worksheet, write out a basic chemical
formula for glycolysis
– Distinguish between reactants (input) and
products (output)
– Label each product as usable or waste
Step 2: Krebs Cycle/
Citric Acid Cycle
• Breakdown carbon chains into CO2
(Now get to radio, speakers…you get idea!)
– Pyruvate turned into Acetyl CoA
– Acetyl CoA broken down into CO2
– H+ & e- stripped off, transported as NADH, FADH2
– Energy released stored as ATP
– End products: 2 ATP, 3 NADH, FADH2, 3 CO2
– Remember each glucose give 2 pyruvate,
therefore TWO turns in Citric Acid Cycle
Step 2: Krebs Cycle/
Citric Acid Cycle
• In your worksheet, write out a basic chemical
formula for Citric Acid Cycle
– Distinguish between reactants (input) and
products (output)
– Label each product as usable or waste
Step 3: Oxidative Phosphorylation
Time to go clubbing!!!
(go shorty, its your birthday…)
• Two Parts in Oxidative Phosphorylation
– Electron Transport Chain
– Chemiosmosis
• Basic Concept: Use H+ and high energy eproduced in Glycolysis and Citric Acid Cycle to
create massive amounts of ATP
Step 3: Oxidative Phosphorylation
• Electron Transport Chain
– High energy from e- passed
through protein complexes
embedded in inner
mitochondrial membrane
– (club hopping)
– Energy (cover charge) is used
to pump H+ across membrane,
creating high [H+] in
intermembrane space
– Low energy e- bonds with O2
and H+ to safely create H2O
Illustration of
Electron Transport Chain
Step 3: Oxidative Phosphorylation
• Chemiosmosis
– High [H+] created in intermembrane space starts
to flow back into matrix (diffusion)
– Can only flow back into matrix through protein
called ATP synthase
– Each H+ that flows through turns “crank” in ATP
synthase that creates ATP
– Chemiosmosis creates 32-34 ATP per glucose
molecule
Illustration of Chemiosmosis
Step 3: Oxidative Phosphorylation
• Summary
– Use NADH, FADH, and H+ created from first two
steps to create high [H+]
– As H+ move, ATP created via ATP synthase
– O2 used to accept low energy e- to safely create
H2O
Step 3: Oxidative Phosphorylation
• In your worksheet, write out a basic chemical
formula for Oxidative Phosphorylation
– Distinguish between reactants (input) and
products (output)
– Label each product as usable or waste
Review Questions
•
•
•
•
Which step creates CO2?
Which step creates most ATP?
What happens to the O2 we breathe in?
True or False:
You need O2 in order for all steps to occur.
• What is the purpose of NAD+ and FAD?
• What is pyruvate?