Why does baking bread require a constant input of heat from the oven?

it is an endothermic reaction.

it is a chemical reaction.

it is a physical reaction.

it is an exothermic reaction.

Baking of bread is an endothermic process.

Explanation:

In order to bake bread a constant supply of heat energy is required. Since absorption of heat takes place while bread gets baked this is an endothermic reaction. The microbe used in bread making is yeast which helps in puffing up the bread.

Puffing up of bread is caused by the release of carbon dioxide by yeast when it feeds on the sugars in the dough.  For yeast to become active it should come in contact with warm water. Thus heat is an essential input in bread making process.  

it is a solid

explanation: