Download Cellular respiration

CELLULAR RESPIRATION
Aerobic Energy Pathway
LEARNING GOALS
• I will be able to connect Glycolysis to Aerobic Respiration.
• I will understand what is released, produced and formed during the first two
stages of Aerobic Respiration.
LET’S WATCH
• Cellular Respiration Overview
CELLULAR RESPIRATION (AEROBIC)
• provides the energy for ATP synthesis when we’re not working at our
max (i.e., most of the time), therefore, most important E! system
• during intense work up to 3 minutes...provides 50% of the total E!
for ATP synthesis
• exercise lasting longer than 10 minutes = up to 95% of the total E!
for ATP synthesis
ATP resynthesis from the complete breakdown of GLUCOSE
(or fats, or proteins)
3 STAGES OF
CELLULAR RESPIRATION
GLYCOLYSIS (the unofficial first step)
1. CONVERSION OF FUEL TO ACETYL-CoA
2. KREB’S CYCLE
3. ELECTRON TRANSPORT CHAIN
• let’s watch again
1.CONVERSION
Purpose: to convert pyruvate into Acetyl-CoA so
it can enter the Citric Acid/Kreb’s Cycle
• it is here that fats and proteins can ‘enter the
picture’ (i.e., be used as a fuel source)
• it is also when we move from the sarcoplasm into
the mitochondria for the first time
CARBS
FATS
fatty acids
pyruvate (3C’s) PROTEINS
ACETYL-CoA (2 C’s)
as pyruvate is broken down into
acetyl-CoA some more H+, C
and O are released
amino acids
1. each pyruvate (3C’s) is converted to an acetyl-CoA (2C’s)
and:
•
extra carbon from each pyruvate is released (with some
oxygen) as CO2
•
H+ ions released during the conversion are picked up
by NAD, forming one NADH+H per pyruvate
2. both acetyl-CoA molecules move on to Kreb’s Cycle
Stage 1 (note CO2 &
NADH+H)
ACETYLCOA
NADH+H
CO2
2
2
2
2. KREB’S CYCLE
Purpose: to remove remaining high energy H+ ions from glucosebased molecules
• through series of 8 reactions, the remaining H+ ions stored in the bonds of
acetyl-CoA are released and picked up by “carrier” molecules
1. acetyl-CoA binds with oxaloacetate (4C’s), producing citrate (6C’s)
2. through a series of 8 reactions, citrate becomes oxaloacetate again
(releasing 2 C’s), H+ ions are released (which are picked up by “carrier”
molecules NAD & FAD) and:
•
2 CO2 are released
•
3 NADH+H are formed
•
1 FADH2 is formed
•
1 ATP is produced
3. oxaloacetate is now ready to bind with the second acetyl-CoA (thus,
Kreb’s “cycle”) and cycle repeats for the second acetyl-CoA
Net per Acetyl-CoA:
1 ATP
3 NADH+H
1 FADH2
Net per Glucose:
2 ATP
6 NADH+H
2 FADH2
ANOTHER VIDEO
• Kreb’s Cycle
ATP
NADH+H
FADH2
2
6
2
STAGES 1 & 2 OF AEROBIC SYSTEM
REVIEW
1. Where does each of the following systems occur in a muscle
fibre: ATP-PC System? Glycolysis? Aerobic System?
2. What is another name for the Aerobic System?
3. Describe the conditions under which an athlete would be
relying mostly on the Aerobic System to produced ATP.
4. What must proteins and fats be converted into in order to be
used as fuel for the Aerobic System?
5. By the end of the Kreb’s Cycle, there is nothing left of the
original glucose molecule. Where did each of the elements go?
6. How many carbons are in: G3P, pyruvate, lactic acid, acetylCoA, citrate, oxaloacetate, carbon dioxide
7. What are the 2 “carrier molecules”? What are they
carrying? Why is their ‘cargo’ important?
8. How many times does the Kreb’s Cycle ‘cycle’ per glucose
molecule?
9. Name 4 different molecules that are produced/released
during 1 turn of the Kreb’s Cycle (and list how many of
each).
10.Review your notes to calculate the total number of NAD
carrier molecules that have picked up H+ ions since the
beginning of glycolysis.
LEARNING GOALS
• I will be able to connect Glycolysis to Aerobic Respiration.
• I will understand what is released, produced and formed during the first two
stages of Aerobic Respiration.