Original video: https://youtu.be/X3c81GRbN2M
Delivered on: 27 NOVEMBER 2023
Photorespiration is a complex process that occurs in plants when the enzyme rubisco, responsible for carbon fixation in photosynthesis, binds with oxygen instead of carbon dioxide. This creates a toxic byproduct that the plant must recycle through a series of reactions involving three organelles: the chloroplast, peroxisome, and mitochondrion. This process, while metabolically expensive, is essential for plants to recover carbon, maintain metabolic stability, and protect themselves from damage.
Figure 10.2 The Oxygenation Reaction of Rubisco and Photorespiration
Figure 10.8 Photorespiration minimizes the loss of fixed CO2 by the oxygenase activity of Rubisco
Figures 10.8, 10.9 Chloroplasts, peroxisomes, and mitochondria participate in the movement of carbon, nitrogen, and oxygen atoms through photorespiration
Kinetic properties of Rubisco, temperature, and the availability of atmospheric CO2 and O2 control the balance between the Calvin–Benson cycle and photorespiration.
List of Key Terms
1. C4 photosynthesis
2. Calvin–Benson cycle
3. Crassulacean acid metabolism (CAM)
4. Ferredoxin–thioredoxin system
5. Induction period
6. Kranz anatomy
7. Photorespiration
8. Rubisco
9. Starch
10. sucrose C1 C2 C3 C4 CAM Carbon Metabolism
Video Timestamps:
0:00 Introduction and Recap
2:00 Introduction to Photorespiration
4:30 Operation of Photorespiration
11:27 Reactions in the chloroplasts
16:02 Reactions in the Peroxisome
23:19 Reactions in the Mitochondrion
30:32 From Mitochondrion back to the Peroxisome
34:39 Glycerate moves back to chloroplasts
36:16 C1 Cycle
44:13 The oxygenation of ribulose 1,5-bisphosphate sets in motion photorespiration
47:29 Carbon Cycle
47:41 Nitrogen cycle
48:04 Oxygen Cycle
49:38 Michaelis –Menten kinetics
53:21 Km value
54:26 Three aspects regulate the distribution of metabolites between the Calvin-Benson cycle and photorespiration
1:00:00 Conclusion of lecture
Keywords: Photorespiration, C2 cycle, Calvin cycle, Rubisco, Photosynthesis, Plant metabolism, Carbon fixation, Oxygenation, Chloroplast, Peroxisome, Mitochondria, Phosphoglycolate, Glycolate, Glyoxylate, Glycine, Serine, Hydroxypyruvate, Glutamate, Transamination, GDC, Glycine Decarboxylase Complex
Location:
Faculty of Agriculture, Universiti Putra Malaysia
Fakulti Pertanian, Universiti Putra Malaysia, 43000 Seri Kembangan, Selangor
XPMM+9J Seri Kembangan, Selangor
2.9845517506267742, 101.73803356324866
Attribution 4.0 International — CC BY 4.0 - Creative Commons
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