The organelle where the Krebs cycle, electron transport chain and oxidative phosphorylation occur is

a. vacuole

b. chloroplast

c. peroxisome

d. mitochondrion

e. ribosome

Mitochondria

Explanation:

krebs cycle occurs in mitochondria where acetyl coA is broken down to carbon dioxide, water and energy. Oxidative phosphorylation involves energy precursors which leads to the phosphorylation of ADP, producing ATP. This also occurs in the mitochondria. during electron transport chain, the high energy molecules are driven to produce ATP.