Unit 1:principles of Anatomy and Physiology

Energy systems

Kevin Browne

Learning Objectives

All students will be able to: To define the terms aerobic and anaerobic Identify the three different types of energy

systems

Introduction

Any form of activity within the human body requires ENERGY.

This form of activity could be enzyme secretion, nerve stimulation, contraction of the heart or physical activity.

Creating Energy

In order for the human body to create energy, it will either use the process of:

Aerobic respiration Anaerobic respiration

Student ActivityIn pairs, define the terms aerobic respiration

and anaerobic respiration, and discuss any similarities or differences in the two.

Aerobic respiration

Aerobic exercise can be maintained for long periods without the performer getting breathless or suffering muscle cramps. Moderate activities like walking, jogging, cycling and swimming use aerobic respiration.

There are two different types of respiration.When you exercise at a steady, comfortable rate, the cardiovascular system is able to supply the muscles with all the oxygen they need.

Under these conditions, aerobic respiration takes place.

glucose + oxygen energy carbon dioxide+ + water

Anaerobic respirationWhen you exercise at a high intensity, the cardiovascular system cannot supply enough oxygen to the muscles.Under these conditions, anaerobic respiration takes place.

With no oxygen available, glucose is burned to produce energy and lactic acid.Lactic acid is a mild poison. As it builds up, it causes muscle pain and eventually cramp.Short, intense activities like sprinting, weightlifting, jumping and throwing use anaerobic respiration.

glucose energy + lactic acid

Energy SystemsThere are two types of energy types in the body

Anaerobic is the release of energy without oxygen for short bursts.

Aerobic is a sustained release of energy with oxygen for longer endurance events.*

DiscussionHow do these types of systems, create energy?

The muscles of the body use both carbohydrates and fats to produce energy.

There are 3 energy systems, and each system will produce energy in a slightly different way through

chemical reactions. The three energy systems are:

ATP-CP system Anaerobic Glycolysis (latic acid system)

Aerobic Glycolysis

Starchy CHO from food is converted to glucose in the gut, which enters the small intestine and passes into the bloodstream to be transported to the muscles.

The glucose is then used in 3 different ways…

Here some of the glucose is stored as glycogen and used to maintain blood sugar levels.

Glucose is stored here as glycogen and is used when the body is working harder.

Glucose diffuses easily into the cells and is used to meet their energy demands.

Skeletal Muscle

LiverBody Cells

Student ActivityResearch and quick presentationsYou will be split into three groups, each group

will look at a different energy system, and will answer the following questions:

How long does it take to produce energy? Explain the chemical process of your energy

system Which sports will use this energy system Conditions: you may only use 10 words to summarise

the information from the text but can use as many diagrams/symbols

How do these systems work? The body has to create energy chemically! BUT

HOW? In the muscles is

adenosine triphosphate (ATP).

This is quickly converted to adenosine diphosphate (ADP).

The by-product is Energy which is released.

This is not sustainable and the body must use other chemicals to convert ADP back to ATP and continue the process of making energy.

This is done in 3 ways.. .

This is what ATP LOOKS Like

Special high-energy bonds exist between the phosphate groups and breaking one of the phosphate bonds releases the energy. ATP is broken down into adenosine diphosphate (ADP) and free phosphate (Pi) releasing the stored energy.

http://oldlearnzone.loucoll.ac.uk/NLN/Science/Biology/Life%20Sciences/workshop3_RH4_Energy%20systems/472AA547-FB87-4788-9277-9A48354BC642/453_sco.html

Creatine Phosphate (CP) Energy System This generally follows on from the breakdown

of ATP and uses the two substances combined into ATP-CP system.

This system use CP stored in muscles, which splits to allow the Phosphate to join ADP and create more ATP.

This new ATP can then be used to create energy as before

The quantity of ATP in the muscles is very limited so once this breakdown has occurred the ADP needs to be resynthesised back into ATP to ensure the constant generation of energy within the body. Note that energy is required to resynthesise ATP and it is the energy we get from food that provides this.

Creatine Phosphate (CP) Energy System

This system is very efficient, uses no oxygen and creates no waste product, but it is limited to about 10-15 seconds before running out.

Lactic Acid System (Anaerobic Glycolysis) When CP runs out, the muscles call upon the stores of glucose

(glycogen).

Unfortunately this system creates a waste product called pyruvic acid.

Ideally the body copes with this by, oxygen breaking down the pyruvic acid into carbon dioxide and water.

But, if activity levels are too intense and not enough O2 can be inspired, then the pyruvic acid is not broken down and converts into lactic acid.

Lactic Acid System (Anaerobic Glycolysis) If lactic acid is allowed to build up it the muscles fatigue and

either the work-rate must be reduced or the individual will be forced to stop.

Now they must rest while fresh oxygen is supplied to repay the oxygen debt.

Who can think what the term oxygen debt refers to?

“The additional oxygen that must be taken into the body after vigorous exercise to restore all systems to their normal states is called oxygen debt” (A.V. Hill 1886-1977).

Aerobic Energy System

1. Glucose and oxygen are transported to the working muscles bythe blood.

Aerobic respiration involves the release of energy from the slow breakdown of glucose using oxygen, inside the cells.

2. Glucose and oxygen are then used by the muscles of the body to produce energy.

3. This process creates carbon dioxide and water.4. The carbon dioxide passes back into the blood for removal.

The Process of Aerobic Respiration

Energy for Musclesto contract and

create Movement

Water

CarbonDioxide

Glucose

Oxygen

3. AerobicIf you change activity to a a steady jog on the spot you will start to

use a different system.

You are now using your Aerobic system.

You are still using glycogen from your body stores.

But now the pyruvic acid is being broken down by the oxygen to produce water and CO2.

The Aerobic system is used by anyone doing a sustained activity like jogging.*

How long could you keep running for? As long as you keep a supply of oxygen

it depends on your glycogen supply.

The glycogen comes from the carbohydrates in your food.

These are broken down and stored.

As you tire your body will be using up the glycogen in your muscles and be looking for the other supplies like in fats.

Endurance athletes will feel these body changes and look for warning signs (hitting the wall).*

Worksheet

1. Identify the 3 energy systems.

2. Define the terms below: Aerobic respiration and Anaerobic respiration

3. Explain the chemical process of the ATP-CP system.

4. Explain the chemical process of Anaerobic and Aerobic Glycolysis by filling in the spaces, using the words on the worksheet: