Breakdown of complex molecules to yield energy takes place in

Which of the following processes involves the loss of two protons and two electrons?

Select the correct statements from the following:
$I-$ During respiration,plants take in $CO_2$ and release $O_2$.
$II-$ The surface of most cells in plants is in contact with air.
$III-$ The loose arrangement of parenchyma cells in leaves,stems,and roots creates a network of air spaces.
$IV-$ The energy released during respiration is stored in the form of $ATP$.
$V-$ Glucose is oxidized to release energy in only a single step.

Choose the incorrect sentence.

Transfer of yeast cells from anaerobic to aerobic condition will

Assertion : Glycolysis is the first step of respiration in which glucose completely breaks into $CO_2$ and $H_2O$.
Reason : In this process,there is net gain of twenty four molecules of $ATP$.