Summary BSCI 170 Cellular Respiration Overview

This summary outlines the inputs and outputs for cellular respira4on. Understanding it as a
story will help you recognize the molecules involved in each part of the process. While I won't
ask you to write full molecule names or describe every step in detail as open-ended ques4on,
you should be able to associate the molecules with their respec4ve stages.
For instance, you won't be required to write out full molecule names or describe each step in
detail, such as explaining steps 1-5 of glycolysis. However, you should be familiar enough with
the storyline and the molecules involved to answer various ques4on formats, such as mul4ple
choice, matching, or arranging steps in the correct order, using a provided descrip4on bank. A
solid understanding of the cellular respira4on process and the associated molecules will be key
to successfully answering these types of ques4ons.

Glycolysis (10 steps):
Energy Investment Phase (Steps 1-5):
1. Glucose + ATP → Glucose 6-phosphate(G6P) + ADP
2. Glucose 6-phosphate(G6P) → Fructose 6-phosphate(F6P)
3. Fructose 6-phosphate(F6P) + ATP → Fructose 1,6-bisphosphate(F1,6BP) + ADP
4. Fructose 1,6-bisphosphate(F1,6BP) → Dihydroxyacetone phosphate(DHAP) +
Glyceraldehyde 3-phosphate(G3P)
5. Dihydroxyacetone phosphate (DHAP) → Glyceraldehyde 3-phosphate(G3P)
Energy Genera9on Phase (Steps 6-10):
6. Glyceraldehyde 3-phosphate(G3P) + NAD+ + Pi → 1,3-Bisphosphoglycerate(1,3
BP) + NADH
7. 1,3-Bisphosphoglycerate(1,3BP) + ADP → 3-Phosphoglycerate(3PG) + ATP
8. 3-Phosphoglycerate(3PG) → 2-Phosphoglycerate(2PG)
9. 2-Phosphoglycerate(2PG) → Phosphoenolpyruvate(PEP)
10. Phosphoenolpyruvate(PEP) + ADP → Pyruvate + ATP
Inputs: 1 Glucose, 2 ATP
Outputs: 2 Pyruvate, 2 NADH, 4 ATP, 2 H2O
Net ATP: 2 (2 ATP used, 4 ATP generated)

Pyruvate Oxida9on:
1. Pyruvate + NAD+ + CoA → Acetyl-CoA + NADH + CO2
Inputs: 2 Pyruvate, 2 NAD+
Outputs: 2 Acetyl-CoA, 2 NADH, 2 CO2
Net ATP: 0 (no ATP used or generated)

Citric Acid Cycle (=TCA cycle or Krebs cycle, 8 steps):
1. Acetyl-CoA + Oxaloacetate + H2O → Citrate + Coenzyme A
2. Citrate → Isocitrate
3. Isocitrate + NAD+ → α-Ketoglutarate + NADH + CO2
4. α-Ketoglutarate + NAD+ CoA → Succinyl-CoA + NADH + CO2
5. Succinyl-CoA → Succinate + ATP
6. Succinate + FAD → Fumarate + FADH2