What Is Bioenergetics? — Definition & Overview

What Is Bioenergetics?

One saving grace of science words is that they can almost always be broken down into smaller, less overwhelming pieces. Let's take a look.

So, bioenergetics is the study of energy in living things. It includes how energy is transformed (changed from one form into another) through two major processes: cellular respiration and photosynthesis.

To really understand what this word means, let's take a closer (but still brief) look at how energy is transformed in cellular respiration and photosynthesis.

Cellular Respiration

Cellular respiration (or some variation of it) occurs in all living things. In eukaryotes, cellular respiration occurs in the cytoplasm and primarily in the mitochondria.

The main purpose of cellular respiration is to take a sugar molecule like glucose (a simple sugar) and break it apart to release energy in the form of ATP.

Think of ATP as energy currency. ATP molecules can instantly release energy when the cell needs it.

Photosynthesis

Photosynthesis occurs in most plants, most algae, and some types of bacteria. In eukaryotes, this process occurs in an organelle called the chloroplast.

In photosynthesis, light (a form of energy), carbon dioxide, and water are transformed into glucose.

This is the same glucose that gets broken down in cellular respiration. Funny how it all comes together, isn't it?

Ballad of Bioenergetics

If you study bioenergetics

You may think it is rather hectic.

As molecules are compelled

To break or to meld

You find yourself feeling apoplectic.

Just remember that as energy changes

It travels wide molecular ranges.

From synthesis to respiration,

Taking stops at organelle stations,

All that power, a cell rearranges.

ATP is the main ingredient

In reactions, it is expedient

In oxidative phosphorylation

Where each electron ration

Puts new energy out a mitochondrial vent.

Or when glucose is broken down

Catabolism comes to town

And takes from glucose power

To make more ATP each hour.

During respiration, energy abounds.

But when photosynthesis is at play

Such as in all plants during the day

Anabolism instead takes hold

And makes sugar from sunlight gold

Which then waits to be used in a catabolic way.

Photosynthesis and Cellular Respiration

Bioenergetics is the study of how energy flows through a living system. In other words, it is the study of how organisms harvest and use energy. We will be looking at photosynthesis and cellular respiration as examples. The currency of energy, ATP, plays a key role in bioenergetics.

During cellular respiration, the mitochondria break down glucose to harvest chemical energy (ATP). This process is known as catabolism. The prefix cata- means breakdown or downward. We can also recognize the -bolism in metabolism, which refers to change. So, catabolism refers to the breaking down of metabolic compounds.

During photosynthesis, the chloroplasts capture and use the light energy from the sun to produce glucose. This process is known as anabolism. The prefix ana- means up, back, or again. We see -bolism come up again here, which refers to change. So, anabolism refers to the formation of metabolic compounds.

$$\color{#8925AE}{\text{Vocabulary Review:}}$$

$\color{#8925AE}{\text{Bioenergetics}}$ : The study of how energy flows through a living system

$\color{#8925AE}{\text{ATP}}$ : Adenosine triphosphate, an energy storing molecule

$\color{#8925AE}{\text{Photosynthesis}}$ : Process that converts sunlight into energy

$\color{#8925AE}{\text{Cellular Respiration}}$ : A set of complex chemical reactions that provides a cell with energy

(Video) Bioenergetics: The Transformation of Free Energy in Living Systems

by khanacademymedicine

The study of energy covers a lot of what happens in nature. All living things need energy, after all. This video defines bioenergetics and gives some examples of different bioenergetic processes.