Transcript 5.1 Energy Systems - Blyth-Exercise

Energy Systems
Lesson 5.1
Where do we get Energy for
our working muscles?
The Three Energy Nutrients
 Proteins
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 Fats
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 Carbohydrates
Carbohydrates
• Carbohydrates are broken down into
glucose and stored into the muscle as
glycogen.
• Most easily broken down into this state
which is why they are the first thing our
body uses as a form of energy.
Proteins
• Proteins are broken down into amino
acids.
• Proteins are used for energy when the
body is in starvation mode.
Fats
• Fats are broken down in to fatty acids and a
glycerol.
• Fats are the LAST energy source which is used.
How does our body
use what we eat?
How does our body use what we eat?
Adenosine DI phosphate
(missing a phosphate and
can not produce energy)
1 molecule of
GLUCOSE
=
2 molecules ATP
Consumption of
food
Energy production
Food is broken
down by the
body into
GLUCOSE
(primary fuel
source)
• ATP = Adenosine TRI Phosphate
– 3 phosphates are present
Adenosine Triphosphate (ATP)
 Adenosine triphosphate (ATP)
 ATP is a usable form of energy
for the body.
 Made in the mitochondrion
 Resynthesized in two ways
Aerobically
Anaerobically
ATP
ADP + Pi + ENERGY
• ATP is the molecule that gives every cell
in our body energy to function.
• All things in our body require energy in
order to be able to function properly.
– Food metabolism
– Heart beat
– Muscles contract
• When you need energy it is on.
• When you don’t need energy it is being
stored and not used.
2 ways to re-synthesize ATP
Aerobic System
Two Energy Systems
 Aerobic System
In the presence of oxygen (O2)
All of its metabolic activity will involve O2
Occurs in the mitochondria
Leads to the complete breakdown of glucose
• With the presence of oxygen you are able
to perform an activity over a long period of
time with a balanced intensity.
• What is an example of “aerobic activity”
– Requires oxygen
• How does your body react?
– Heart rate increases
– Breathing increases
Aerobic System
• Any activity longer than 90s
• Mitochondria of cells
• C6H12O6 + 6O2 +36ADP +36Pi --> 6CO2 + 36ATP 6H2O +
E
ETC – the finer details
• When oxygen is reduced, it also bonds with 2 H+,
and forms one H2O (inside the matrix)
• Oxygen is the final electron acceptor (This is why we need
oxygen to live!)
ATP Synthase
http://www.youtube.com/watch?v=KU-B7G6anqw&feature=fvst
Anaerobic
• Occurs in the muscle fiber, only using chemicals and
enzymes readily available.
• Smaller amounts of energy are produced
• No oxygen is needed for this reaction
• Needed for short and medium length activities.
– Ex: weight lifting, short shifts in hockey
The two systems do not act as
opposing systems.
The two systems co-exist.
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Three Metabolic
Pathways
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Three Metabolic Pathways
• Within the ANAEROBIC and AEROBIC
systems, there are 3 metabolic pathways
by which ATP energy reserves are
restored:
– ATP-PC pathway (anaerobic alactic)
– Glycolysis pathway (anaerobic lactic)
– Cellular respiration (aerobic)
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High Energy Phosphate System
P
ENERGY
Creatine
ADP + Pi  ATP
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ATP-PC System
 ATP-PC System
(anaerobic alactic)
 First of two anaerobic
energy pathways
 Relies on the action of
stored ATP and
phosphocreatine
 Yields enough ATP for
7-12 seconds of energy
 Provides highest rate of
ATP synthesis
PC + ADP
ATP + CREATINE
ATP-PC
• Plays an important role in sporting events
which only last a few seconds, but require
large bursts of energy.
– Ex: Olympic weight lifting, high jump, 50-100
m dash.
• HOWEVER – muscles do not have large
supplies of phosphocreatine, and after
about 10-15 seconds, body begins to rely
on the seond system.
High Energy Phosphate System
Overview
Primary energy source:
Stored ATP, CP
Duration of activity:
7 to 12 s
Sporting events:
Weightlifting, high jump, long jump, 100
m run, 25 m swim
Advantages:
Produces very large amount of energy
in a short amount of time
Limiting factors:
Initial concentration of high energy
phosphates (ATP, PC)
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The Anaerobic Glycolytic System
Glycogen
ENERGY
Lactic Acid
ADP + Pi  ATP
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Glycolysis
• A biochemical process that releases energy in the
form of ATP from glycogen and glucose
•
anaerobic process (in the absence of oxygen)
• The products of glycolysis (per molecule of
glycogen):
- 2 molecules of ATP
- 2 molecules of pyruvic acid
• The by-product of glycolysis (per molecule of
glycogen):
- 2 molecules of lactic acid
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The Anaerobic Glycolytic System
• Starts when:
– the reserves of high energy phosphate
compounds fall to a low level
– the rate of glycolysis is high and there is a
buildup of pyruvic acid
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Anaerobic Threshold
• The exercise intensity at which lactic acid begins to
accumulate within the blood
• The point during exercise where a person begins to feel
discomfort and burning sensations in the muscles
• Lactic acid is used to store pyruvate and hydrogen ions
until they can be processed by the aerobic system
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Substrates for the anaerobic energy system
• The primary source of
substrates is
carbohydrate
• Carbohydrates:
– primary dietary source
of glucose
– primary energy fuels
for
brain, muscles,
heart, liver
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Carbohydrate breakdown and storage
Complex
Carbohydrates
Digestive
system
Glucose
Blood
Stream
Circulation of glucose
throughout body
Glucose stored
in blood
Glucogenesis
Glycogen
Glycogen stored
in muscle or liver
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LACTIC ACID CHALLENGE 
What is lactic acid challenge?
• This is a class challenge.
– Find an place on the wall, and the person who
can perform a wall sit for the longest – will win
a prize!
• Describe what you felt that made you want
to stop?
What is lactic acid?
• After 2 or 3 minutes of a sustained activity
the body can not break down glucose fast
enough to keep up.
• Lactic Acid builds up in the muscle fibers
• You are forced to slow down/stop – as it
causes pain/discomfort in the muscle.
The Anaerobic Glycolytic System Overview
Primary energy source:
Stored glycogen, blood glucose
Duration of activity:
12 s to 3 min
Sporting events:
800 m run, 200 m swim, downhill ski
racing, 1500 m speedskating
Advantages:
Ability to produce energy under
conditions of inadequate oxygen
Limiting factors:
Lactic acid build up, H+ ions build
up (decrease of pH)
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The Role of Three Energy Systems During an Allout Exercise Activity of Different Duration
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