Transcript How the Body Obtains and Uses Energy

How the Body Obtains and
Uses Energy
Copyright 2010. PEER.tamu.edu
Discuss:
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Are you an energetic
person?
When do you have
the most energy?
What do you do when
you need to get more
energy?
Energy
Energy is all around you!
You can hear energy as sound.
 You can see energy as light.
 And you can feel it as wind.
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When do you use energy?
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You use energy
when you
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hit a softball.
lift your book
bag.
grow.
study.
do any activity.
Why is energy important to our
bodies?
Living organisms need energy
for their bodies’ daily
activities and processes.
Try to Recall the
Six Forms of Energy
The six main forms of
energy are:
Heat or Thermal
 Chemical
 Electromagnetic
 Nuclear
 Mechanical
 Electrical
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Our bodies use Chemical Energy
States of Energy
There are two states in which energy can exist:
Potential Energy
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Stored energy
Energy that
could be used
Kinetic Energy
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Energy of Action or
Motion
Energy that is being
used
Energy Conversions or Transformations
Energy can be changed from one form,
or state, into another. Changes in the
forms or states of energy are called
energy conversions or
transformations.
An Essential Energy Conversion
• Our body converts starches, sugars, fats and even
proteins (chemical energy) that we eat into energy
for our bodies’ daily functions (mechanical and
heat—or thermal—energy).
Chemical Energy
 Mechanical and
Heat Energy
How the Body Obtains Energy
First, you consume energy
in the form of foods.
Foods are made of
organic molecules.
The organic compounds in
foods that can be used for
energy are:
Carbohydrates
 Fats
 Proteins
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Molecules are held together by an
energy force. Breaking the bonds
between atoms in the molecules
releases that energy.
A Glucose (sugar)
Molecule
C6H12O6
Whether or not that bond energy
does anything depends on whether
it can be captured and "put to
work."
The body's job is to break food down
so that cells can break down some
of the chemical bonds. Then that
energy can be used to do things.
Any leftover energy escapes as heat.
Bond between atoms
in the molecule.
During the digestion process, how does the body
break down foods into smaller organic compounds?
The teeth first break down the food
physically into smaller pieces.
The movement of the stomach
and intestines also help physically
break the food.
Proteins are broken down chemically
by pepsin in the stomach into
amino acids.
Carbohydrates are broken down
chemically into sugars
(monosaccharides) by enzymes
found in saliva in the mouth and
by enzymes in the small intestine.
Fats are broken down into fatty acids
in the small intestines by bile
from the liver.
These smaller molecules are transported into body cells and then
go through several chemical processes that break the molecular
bonds to produce ATP, a primary storage form and source of
energy in the body.
These chemical processes occur in the cytoplasm and
mitochondria of the cells.
Mitochondria
Cytoplasm
For more on energy use in the body please click here
Mitochondria (plural of mitochondrion) are the organelles that
cells use as their energy factories. Think of them as the cell's
way of recharging its battery.
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An artist’s
representation of a
mitochondrion
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An electron
micrograph of a
mitochondrion
A mitochondrion is an oval bag that is filled with membranes.
Mitochondria are so small that you can only see them with the
high-power magnification of an electron micrograph.
Stop and Think:
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What is an energy conversion or
transformation?
What energy conversion is essential for
the human body?
Summarize how humans get their
energy from food. Be sure to include
the structures in the body that are
responsible for this process.
Calories
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Calories are a unit of
measurement of food
energy. They measure the
amount of potential heat
energy contained in the
chemical bonds of a food.
People need a certain
amount of calories per day.
For the average teenage girl,
the recommended daily
allowance is 2200 calories.
The average teenage boy
needs 2500-3000 calories.
Calories add up fast!
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A large cheeseburger, fries, and a
soda can add up to more than
1,390 calories.
That’s more than half
of the calories that
most teens need in one
day! This is not a good deal
for your body because this
meal does not contain many
of the other nutrients your
body needs (besides
calories).
Our Energy Use Must be Balanced!
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The amount of energy that comes into
our body should be equal to the amount
of energy that we use.
If it is not, we STORE the extra
(unused) energy.
The main way the body stores excess
energy is in the form of fat.
Did I
eat ALL
of that?
Energy Imbalance Causes Problems
Obesity
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BMI Calculator
A person has traditionally been
considered to be obese if they
are more than 20 percent over
their ideal weight. That ideal
weight must take into account
the person's height, age, sex,
and build.
If their Body Mass Index (BMI)
is between 25 and 29.9 a
person is considered
overweight. If their BMI is 30
or over, the person is
considered obese.
Obesity is a problem in
people and pets!
Childhood obesity has more
than tripled in the past
30 years. The prevalence
of obesity among
adolescents aged 12 to
19 years increased from
5.0% to 18.1%.
An estimated 51.5% of
dogs and cats in the
United States are
overweight or obese.
Common Health Risks of Obesity
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Osteoarthritis
Type 2 Diabetes
Respiratory disorders
Hypertension (high blood
pressure)
Heart Disease
Many Forms of Cancer
How to keep Energy Balanced:
The best way to
balance your
energy is to find
out how much
energy is used by
the body each
day and…..
Energy Used
in a Day
Eat only enough
calories to equal
that amount of
energy.
Energy Consumed
in a Day
Special Considerations for Teens
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Teens have a little
higher energy
requirement than
adults.
Can you guess why?
The answer is that they are growing!
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Growth requires energy
and healthy nutrients
from foods.
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As a teen, you must
choose wisely so you
can reach your
potential!
Can you recall?
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What are calories?
How is extra energy stored in our
bodies?
What are some risks associated with
obesity?
What is meant by “energy balance” in
the body?