Aerobic Energy Pathway Cellular respiration Aerobic Energy Pathway

Learning goals We are learning to connect Glycolysis to Aerobic Respiration. We are learning to understand what is released, produced and formed during the first two stages of Aerobic Respiration.

Let’s watch Cellular Respiration Overview

Ok … where were we? Glycolysis recap!

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) CONVERSION OF FUEL TO ACETYL-CoA KREB’S CYCLE 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 pyruvate (3C’s) PROTEINS fatty acids amino acids ACETYL-CoA (2 C’s) as pyruvate is broken down into acetyl-CoA some more H+, C and O are released

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 both acetyl-CoA molecules move on to Kreb’s Cycle

Stage 1 (note CO2 & NADH+H)

Conversion products ACETYL-COA NADH+H CO2 2

2. KREB’S CYCLE Purpose: to remove remaining high energy H+ ions from glucose-based 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

acetyl-CoA binds with oxaloacetate (4C’s), producing citrate (6C’s) 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 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

Kreb’s products ATP NADH+H FADH2 2 6

Learning goals We are learning to connect Glycolysis to Aerobic Respiration. We are learning to understand what is released, produced and formed during the first two stages of Aerobic Respiration.

STAGES 1 & 2 OF AEROBIC SYSTEM REVIEW Where does each of the following systems occur in a muscle fibre: ATP-PC System? Glycolysis? Aerobic System? What is another name for the Aerobic System? Describe the conditions under which an athlete would be relying mostly on the Aerobic System to produced ATP. What must proteins and fats be converted into in order to be used as fuel for the Aerobic System? By the end of the Kreb’s Cycle, there is nothing left of the original glucose molecule. Where did each of the elements go?

How many carbons are in: G3P, pyruvate, lactic acid, acetyl- CoA, citrate, oxaloacetate, carbon dioxide What are the 2 “carrier molecules”? What are they carrying? Why is their ‘cargo’ important? How many times does the Kreb’s Cycle ‘cycle’ per glucose molecule? Name 4 different molecules that are produced/released during 1 turn of the Kreb’s Cycle (and list how many of each). Review your notes to calculate the total number of NAD carrier molecules that have picked up H+ ions since the beginning of glycolysis.