Photorespiration

1. Photorespiration

2. What is PHOTORESPIRATION? The aberrant use of oxygen by chloroplasts An interference with carboxylation caused by the deviant interaction of RuBisCO with oxygen A process that leads to only one 3PGA being produced in the dark reaction in chloroplasts * RuBisCO - ribulose 1,5-biphosphate carboxylase / oxygenase *3PGA- 3-phosphoglyceric acid

3. Factors that Increases Photorespiration High temperature High O 2 concentration Low CO 2 concentration

4. How Photorespiration Happens??

5. CH 2 OP C=O C-OH C-OH CH 2 OP CH 2 OP C-OH C-OH C-OH CH 2 OP CH 2 OP C- O-OH C=O C-OH CH 2 OP HO- CH 2 OP C- O-OH C-OH C-OH CH 2 OP HO- HO- COO C-OH CH 2 OP CH 2 OP COO PO 4 Phospho- glycolate Peroxisomes Calvin Cycle O 2 3PGA H 2 O RuBP Ribulose-1,5-bisphosphate CH 2 OH COO Glycolate

6. CH 2 OH COO CHO COO CH 2 NH 3 COO CH 2 NH 3 COO CHNH 3 COO CH 2 OH 2 CHNH 3 COO CH 2 OH CH 2 OH CHOH COO 3PGA ATP CO 2 Mitochondria Peroxisomes O 2 Serine Glycine Glycolate Glyoxylate Glycerate NH 3 + From Chloroplasts NH 3 + CH 2 OH C=O COO NADH NAD + Hydroxy pyruvate

7. Peroxisome Mitochondria From Chloroplast

8. Functions of Photorespiration Photorespiration Removes Toxic Metabolic Intermediates Photorespiration Protects from Photoinhibition Photorespiration Supports Plant Defense Reactions Photorespiration is Intimately Integrated Into Primary Metabolism

9. Examples of C3 Type of Plants Wheat Soybean Oat Alfalfa Sunflower Barley

10. C4 Carbon CYCLE Next report: The End of Photorespiration