Download Assignment 4 Help Sheet

Principles of Anatomy and Physiology Assignment 4 Help Sheet
Step 1
You need to introduce the topic of this assignment what is energy for and where do
we get it from? What is the number 1 energy source? And which energy system will
benefit from this the most?
Example Answer
The body always needs a constant supply of energy to help us live; energy is needed for all
forms of movement even the simplest of steps need energy. This energy is used for growth,
repair and most importantly, in terms of sports participation, muscular contraction. In order for
the muscles to contract they need a constant supply of energy. The main nutrients which
provide energy are……….
Step 2
An extension of the introduction continues here you now need to discuss just what
exactly is energy for and what role does adenosine diphosphate (ADP), adenosine
triphosphate (ATP) and free phosphate play in giving energy.
Example Answer
Energy is needed for the muscular activity to take place. The only useable source of energy in
the body is a compound found in muscle cells called adenosine triphosphate (ATP). ATP is
broken down into adenosine diphosphate (ADP) and free phosphate (Pi) releasing the
stored energy.
Step 3
You now need to discuss the first energy system of ATP-PC system. You need to
include information such as how long does it last for? What happens at this stage?
Diagrams of chemical reactions, what sport would this energy system be relevant to?
How many molecules of energy are produced?
Example Answer
The ATP-PC system uses a substance called creatine phosphate (CP) which is found in small
quantities in the muscles. When the high energy bond in CP is broken the energy is released
and used to resynthesise ATP in the muscles. There is enough CP in the muscles to provide
about 10 seconds worth of exercise.
Step 4
Same as Step 3 but you need to apply this to the lactic acid system.
Example Answer
The lactic acid system again provides short-term energy to the muscles. If an athlete works
beyond the capacity of the PC system, which is over 10 seconds, then the energy is provided
by the lactic acid system. No oxygen is needed for this system to work; however the downside
to no oxygen being used is the fact that lactic acid is produced, this causes the muscles to tire.
As you get older, the quicker you get lactic acid, and the longer it takes to get rid of, this is
related to the metabolism. As you are younger your metabolism is working a lot quicker which
means that it is working harder, however as you get older the metabolism slows down, causing
tiring a lot easier, which in turn means there is lactic acid and because the metabolism is slow it
takes longer to break down.
Step 5
You now need to discuss the Krebs cycle, this is fundamental to the linking of the
lactic acid system and the aerobic system. Here you need a diagram of the cycle
which needs referencing and explaining. You also need to discuss the chemical
reactions taking place there and why? As well as the substances involved in the cycle.
You must conclude that the Krebs cycle leads into the Electron Transport Chain.
Example Answer
This is sometimes also known as the Citric acid cycle, or the Tricarboxylic acid cycle, this is the
second phase in the process of aerobic metabolism. The Pyruvic acid produced during
Glycolysis enters the mitochondria and is immediately converted to Acetyl Conzyme A which
combines with Oxaloacetic acid to form a 6 carbon compound, known as Citric acid.
Further chemical reactions occur to wield enough energy to resynthesise 2 ATP molecules. Biproducts of these reactions include Carbon Dioxide (CO2), which is exhaled by the lungs and
Hydrogen (H) which is transported to the site of the Electron Transport Chain by carrier
molecules NAD+ and FAD. The process is termed a cycle due to the starting product of
Oxaloacetic acid is also the end product, ready to start the process over again. This process
then leads into the Electron Transport Chain.
Step 6
You now need to introduce the aerobic system and electron transport chain. Here as
in step 3 you need diagrams etc of the aerobic system but also what happens from the
lactic acid system to the aerobic system. You need to discuss how energy is
formulated and what role does oxygen plays in particular in this area.
Example Answer
This is the system responsible for providing long term energy, and is used in long distance
events such as long distance running (marathon) or far journeys on a bike. The system relies
on carbohydrates and fats as fuels and produces carbon dioxide and water as waste products.
It can only be used in the presence of oxygen and thus energy is released much more slowly,
too slowly to fuel intense or explosive activity.
Step 7
You now need to show you understand how energy is consumed in various sporting
events and explain why it is like that.
Example Answer
The 200m gains 5% of its energy source from the aerobic system as it lasts for 19 to 21
seconds at the highest level, then the athlete will also run through the line and finish with a
victory lap or cool down; this in turn means that there is some drift into the aerobic system.
However it is predominantly anaerobic due to the explosive and intense nature of the event
which means it does not last that long.
Step 8
To finish you need to summarise the efficiency of each one of the systems and
drawing a conclusion which is best. Use the table below to help you.
Example Answer
Energy system Fuel used
Phosphocreatine Creatine
phosphate
The lactic acid
system
(anaerobic
glycosis)
Oxygen Rate of
Duration By
required production
products
No
Very rapid 0-10
None
Oxygen
seconds
required
Glucose/Glycogen No
Oxygen
required
Rapid
Example
activities
Very high
intensity
explosive
events,
such as
shot put.
10secs – 2 Lactic Acid High
minutes
intensity
for short
durations,
e.g. 200
and 400
meter
sprints.
Aerobic system Glucose/glycogen Oxygen is Slow
and fatty acids needed
2 minutes Carbon Long
plus
dioxide
distance
and water events,
running,
cycling and
team
games,.