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TOPIC 3
Energy systems
2
Relationship Between Nutrition, Environment and
Health
External Environment
Religion
Food Security/Insecurity
Culture
Agriculture
Politics
Economics
Education
Health Service
Social Status
Food Security/Insecurity
Nutritional Status
Optimal Nourished
Under-nourished
Over-nourished
Malnourished
Nutritional Requirements
Internal Environment
DNA/RNA
Cells
Organs
Central Nervous System
Metabolism
Blood Circulation
Growth and Development
Pregnancy and Lactation
Sport and Exercise
Elderly
Disease
3.1.1 List the macronutrients and micronutrients.
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Macronutrients are nutrients that provide calories or energy
and are required in large amounts:
Lipid (fat)
 carbohydrate and
 protein.


Micronutrients are nutrients required by humans in small
amounts to orchestrate a wide variety of physiological
functions but are not made by the organism
Vitamins
 Minerals
 Water
 Fiber

Carbohydrates
4
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Food Sources Include:
 Cereals
 Sweeteners
 Fruit
 Dairy
 Bread
 Grains
Functions:
Fuel for your body
Energy storage
Fat
5

Food Sources Include:
 Meat
 Dairy Products
 Oil
 Nuts
 margarine, butter
Functions:
Fuel storage
Hormones
Cell storage
Protein
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
Food Sources:
 Meat
 Eggs
 Cheese
 Milk
 Beans
 Tofu (soy)
Functions:
Structure
Muscle building blocks
Enzymes
Storage
Water
7
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Food Sources
 Beverages
 Fruits
 Vegetables
Functions:
Excretion
Lubrication
Transport
Medium for Reactions
Vitamins
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
Food Sources
 Fruits
 Vegetables
 Fatty Fish

Functions:
Energy release from macronutrients
Immune function
Eyesight
Bone Health
Minerals
9

Food Sources:
 Fruits
 Vegetables
 Fatty Fish
 Milk
Functions:
Mineralization of bones and teeth
Blood oxygen transport
Defense against free radicals
Acid base balance
3.1.3 State the chemical composition of a glucose molecule.
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Glucose – monosaccharide
Carbon, Hydrogen and Oxygen.
It’s chemical formula is C6H12 O6
1:2:1 ratio
3.1.5 Explain how glucose molecules can combine
to form disaccharides and polysaccharides
Carbohydrates
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Monosaccarides have one sugar molecule
 fruits, vegetables and honey
Disaccharides have 2 sugar molecules
 sugar, milk
Polysaccharides have many sugar molecules
 rice, potatoes, corn and wheat
Dehydration Synthesis = Condensation Reaction
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
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the linking of a monosaccharide to another
monosaccharide, disaccharide or polysaccharide by
removal of a water molecule.
Joule: a unit of energy (just like a calorie). Joule is
the energy obtained from food.
1 calorie = approximately 4 joules
Test Your Knowledge:
14

Place the major CHO sources with the correct
country:
 sweet potato
 maize
 cassava
 wheat
 rice
 potato
3.1.6 State the composition of a molecule of triglycerol.

Also known as triglyceride which is a lipid/fat

consists of a glycerol and 3 fatty acid chains

Stored in adipose tissue and skeletal muscle
Structure of triglycerol.
glycerol
Saturated Fatty
acid
What difference do
you notice between
the two?
Unsaturated
Fatty acid
Unsaturated vs Saturated Fatty Acids
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Unsaturated
Saturated
Double bonds between
carbon atoms
No double bonds between
carbon atoms
Come from plant based
foods
Come from animal sources
Examples include peanuts, cashew Tropical oils such as coconut and
nuts, rapeseed and sunflower oil, palm oil. Fat in and around meat,
olive oil and avocado
chicken, pork
Liquid at Room
Temperature
Solid at Room Temperature
3.1.8 State the chemical composition of a protein molecule.
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Protein molecules consist of Carbon, Hydrogen,
Oxygen and Nitrogen.
The smallest part of a protein is called an amino
acid. There are 20 different amino acids
Compose blood tissue, muscle tissue, hormones and
enzymes
3.1.9 Distinguish between an essential and a
nonessential amino acid.

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Essential amino acids NOT synthesized by the
human body and must be obtained by diet
Non-essential amino acids can be synthesized by the
human body
How would this impact a vegetarian?
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3.1.10 Describe current recommendations
for a healthy balanced diet

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Balanced diet: a diet that provides all nutrients in
the right amount in order to maintain health and
prevent nutrient excess or deficiency diseases
Dietary recommendations: recommended amounts
of essential nutrients in the diet
Dietary guidelines: recommended amounts of
foods, food groups or meals
3.1.10 Describe current recommendations for a
healthy balanced diet.
My Plate
Student Thinking Questions
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
Research of dietary recommendations between two
countries of your choice. What are the similarities
and differences between the two countries? Why
do you think there are differences?
3.1.13 State the energy content per 100 g of carbohydrate, lipid and protein.
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Energy in 100 grams:
 Carbohydrate = 1600 kJ (382 calories)
 Protein = 1700 kJ (400 calories)
 Fat =3700 kJ (900 calories)
Both carbohydrates and lipids can be used for
energy storage in humans. Carbohydrates are
usually used for energy storage over short
periods and lipids for long term storage.
Observe the following chart. What do you notice
among the nutrients?
Carbs

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During prolonged, aerobic exercise, energy is
provided by the muscle glycogen stores – which
directly depend on the amount of carbohydrates
ingested.
This is not the only reason why dietary
carbohydrates play a crucial role in athletic
performance; they have also been found to prevent
the onset of early muscle fatigue and
hypoglycaemia during exercise.
Protein

The use of body protein in exercise is usually small,
but prolonged exercise in extreme sports can
degrade muscle, hence the need for amino acids
during the recovery phase.
3.2.1 Outline the terms metabolism, anabolism, aerobic catabolism and aerobic catabolism .

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Metabolism: All the biochemical reactions that occur
within an organism, including anabolic and catabolic
reactions
Anabolism: Energy requiring reactions whereby small
molecules are built up into larger ones
Catabolism: Chemical reactions that break down complex
organic compounds into simpler ones, with the net release
of energy.
3.2.2 State what glycogen is and its major storage sites.

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Glycogen comes from the Greek world glykr
meaning “sweet”
Animals store polysaccharides such as glycogen
in the liver and muscle.
When the diet provides more glucose than the
tissue requires, your body stores glucose as
glycogen.
3.2.3 State the major sites of triglyceride storage.

Major storage site of triglycerides are adipose
tissue (fat) and skeletal muscle.
3.2.4 Explain the role of insulin in the formation of glycogen and the accumulation of body fat.
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Insulin is a hormone produced by the pancreas.
Signals cells to remove glucose from the blood and
use it to create energy or store it.
Glucose is stored in the liver and muscle cells in the
form of glycogen
Insulin also causes fat cells to take in lipids and store
them as triglycerides in adipose tissue.
3.2.4
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Ingest cabohydrates > increase in blood
glucose > insulin is released from
pancreas>cells uptake glucose > less glucose in
blood.
When you exercise, insulin concentration goes
down
Visual
3.2.5 Outline the terms glycogenolysis and lipolysis.
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Glycogenolysis the breakdown of glycogen in liver
and muslces to glucose.
In the liver, the breakdown of glycogen results in
elevated blood glucose.
In the muscle, the breakdown of glycogen is used by
the muscle for energy. There is no release of glucose
into the blood stream from the muscle.
This occurs as a result of the hormone glucagon.
Lipolysis
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Lipolysis is the process of releasing triglycerides from
the body’s fat stores
Excess fat is stored in adipose tissue and muscles
Free fatty acids are released into the blood stream and
throughout the body
breakdown of adipose tissue by glucagon and
adrenaline to increase blood sugar
3.2.6 Outline the functions of glucagon and adrenaline during fasting and exercise.
3.2.6
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During fasting and exercise the blood glucose level
drops and therefore the release of glucagon and
adrenaline will result in an increase of blood
glucose.
Glucagon and adrenaline stimulate the breakdown
of glycogen in the liver to increase blood glucose
levels during long periods of exercise and times of
fasting
3.2.7 Explain the role of insulin and muscle
contraction on glucose uptake during exercise.
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Insulin will result in an increased uptake of blood
glucose into the liver and muscle.
Muscle contraction will also result in an increase of
blood glucose uptake from the blood due to higher
energy demands.
3.3.1 Draw a diagram to show the ultrastructure of a generalized animal
cell.
With ribosomes
Apparatus
3.3.2 Draw a diagram to show the ultrastructure of a mitochondrion.
3.3.3 Define the term cell respiration.
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The controlled release of energy in the form of ATP
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Aerobic Cellular Respiration (aerobic glycolysis)
Cell and Energy Metabolism
3.3.4 Explain how adenosine can gain and lose a phosphate molecule.

ATP is made up of adenosine and three phosphate groups
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ATP releases a great deal of energy when their bonds are broken
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ATP is the energy currency of the cell
3.3.5 Explain the role of ATP in muscle contraction.
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Muscle contraction requires lots of energy
The release of energy caused by the breakdown of
phosphate bonds from ATP to ADP provides the
energy for muscle contraction.
Stored in muscles there is sufficient ATP present to
allow just two seconds of muscle activity
When this runs out another source must be used…
3.3.6 Describe the re-synthesis of ATP by the
ATP-CP system (creatinine phosphate system)

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Creatine phosphate (a high energy molecule) is
broken down to provide a phosphate molecule for
the re-synthesis of ATP during the initial stages of
exercise
This occurs quickly and is important during hard
exercise
Short lived—works for 20 seconds and then you
need another way of getting ATP
Give an example of during what sport you may use
this energy system?
3.3.6 Describe the re-synthesis of ATP by the ATP–CP system.
3.3.7 Describe the production of ATP by the lactic
acid system
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Also known as anaerobic glycolysis—the breakdown
of glucose to pyruvate without the use of oxygen.
Pyruvate is then converted into lactic acid, which
limits the amount of ATP produced (2 ATP
molecules).
The lactic acid system is generally used for high to
medium intensity activities lasting no longer than 2
minutes.
Lactic acid accumulates in the muscle and causes
discomfort and reduces the ability of muscle to
contract > slow down
3.3.7 Describe the production of ATP by the lactic acid system.
3.3.8 Explain the phenomena of oxygen deficit
and oxygen debt
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Oxygen debt now excess post exercise oxygen consumption
(EPOC)
These terms refer to a lack of oxygen while training
Oxygen Deficit. While exercising intensely the body is
sometimes unable to fulfill all of its energy needs.
In order to make up the difference without sacrificing the
output, the body must tap into its anaerobic metabolism.
This where the body goes into a mix of aerobic and anaerobic
energy production.
While not hugely detrimental, oxygen deficits can grow to a
level that the anaerobic energy system cannot cover.
This can cause performance to deteriorate.
Oxygen Debt
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This term describes how the body pays back its debt
incurred above after the exercise is over.
You will notice that even after you have finished
racing you will continue to breath hard.
At this point your body is still trying to repay the
oxygen debt that was created when you were
working hard.
Technically, it is excessive post-exercise oxygen
consumption (EPOC).
Describe the differences between these two diagrams
3.3.9 Describe the production of ATP from glucose and fatty acids by the
aerobic system.
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Within the Mitochondria is the Krebs cycle and
electron transport chain > produce ATP from all
main food groups-usually carbs and fats
Proteins are used for 15 percent of resting energy
metabolism
Fats are broken down by beta oxidation that also
liberates electrons to produce ATP (energy)
3.3.9 Key Points
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
Beginning of exercise:
 anaerobic system that dominates energy provision
 ATP within muscle provides energy for 2 seconds
 Creatine phosphate fades after 20 seconds
 Then lactic acid system dominates but is short lived
 Finally aerobic energy system dominates
 Fats are only used during aerobic activities
Aerobic system
A comparison of anaerobic and aerobic glycolysisDraw this in your workbook
3.3.10 Discuss the characteristics of the three energy
systems and their relative contributions during exercise