The definition of a churn is a device for making butter. An example of a churn is what the Amish use to make butter. verb. To churn is defined as to stir or shake milk or cream with intense movements in the process of making butter, to stir up and agitate, or to produce something at a rapid and regular rate. An example of to churn is for a boat to create waves while moving quickly through the water .
Quick Answer. Plants absorb energy from the sun and use photosynthesis to make sugars. Animals have mitochondria that use the sugars provided by plants to produce their own cellular energy. Plants that produce their own food, and food for other plants and animals using photosynthesis, are called autotrophs.
Mitochondria are the energy factories of the cells. The energy currency for the work that animals must do is the energy-rich molecule adenosine triphosphate (ATP). The ATP is produced in the mitochondria using energy stored in food. Just as the chloroplasts in plants act as sugar factories for the supply of ordered molecules to the plant, the mitochondria in animals and plants act to produce the ordered ATP molecules as the energy supply for the processes of life.