The first reaction in the pentose phosphate pathway is .........

What is the number of oxygen molecules required for the aerobic oxidation of one molecule of pyruvate (in $.5$)?

Match Column-$I$ with Column-$II$ and select the correct option.

Column-$I$	Column-$II$
$a.$ Cis-aconitate	$i.$ $4 \ C$-compound
$b.$ $\alpha$-ketoglutarate	$ii.$ $3 \ C$-compound
$c.$ Fumarate	$iii.$ $6 \ C$-compound
$d.$ $1,3$-diphosphoglyceric acid	$iv.$ $5 \ C$-compound

What are the main steps in aerobic respiration? Where does it take place?

Read the following statements and choose the set of correct statements :
$(A)$ In fermentation,the reducing agent is $NADH + H^+$.
$(B)$ There are three major ways in which different cells handle pyruvic acid produced by glycolysis.
$(C)$ The complete oxidation of pyruvate occurs by the stepwise removal of all the hydrogen atoms,leaving two molecules of $CO_2$.
$(D)$ The $NADH$ synthesised in glycolysis is transferred into the mitochondria and undergoes oxidative phosphorylation.
$(E)$ Complex-$IV$ of $ETS$ refers to cytochrome $c$ oxidase complex.
Choose the most appropriate answer from the options given below :

Respiration is essential for