Cellular Respiration in Plants & Animals
Turning on the Powerhouse
Mitochondria are known as the powerhouses of the cell. They are
organelles that act like a digestive system. They take in nutrients, break
them down, and create energy for the cell. The process of creating cell
energy is known as cellular respiration. Most of the chemical reactions
involved in cellular respiration happen in the mitochondria.
Which Organisms Use Cellular Respiration?
It’s important to realize that BOTH plants (producers) and animals
(consumers) break down sugar to release its energy in a form they can
use. This is because both types of organisms have mitochondria in their
cells (see picture below). It’s just that plants make their own glucose
through photosynthesis and animals need to eat other organisms to get
this valuable sugar.
Cellular Respiration
WATER
(released as vapor)
GLUCOSE (Food)
CARBON DIOXIDE
(released into air)
OXYGEN
Cellular Respiration happens in BOTH plant
cells and animals cells. Specifically, it happens
in the mitochondria. Both organisms need a
way to break down food into usable energy.
Some text adapted from: http://www.biology4kids.com/files/cell_mito.html
ENERGY
(ATP)
Using Oxygen to Release Energy
A glucose (sugar) molecule is like a $100
dollar bill. There is a lot of “stored” energy,
but it can’t be used by the cells right away.
Therefore, this large molecule needs to be
broken down into “usable” $1 dollar bills
called ATP. ATP is a usable form of energy
that the cell can use to run all sorts of
reactions from movement to brain functioning.
However, oxygen is needed to break apart
the large glucose ($100) into smaller energy
packets ($1). Waste by-products, carbon
dioxide gas and water are released in the
process.
The process can be expressed in the chemical equation:
Ingredients
Products
$100
$1
The Link: Photosynthesis & Respiration
If you really stop to think about it,
photosynthesis and respiration are
OPPOSITE processes. Just analyze
the picture. During photosynthesis,
plants produce oxygen and release it
into the air. Animals breathe in this
oxygen and use it to break down the
glucose they receive from eating other
organisms. The animal then releases
carbon dioxide back into the air. The
plant takes this in to run
photosynthesis and make sugar once
again.
Some text adapted from: http://www.biology4kids.com/files/cell_mito.html