Topic 3

Question 1

List the macronutrients and
micronutrients.

Answer 1

Macro: lipid (fat), carbohydrate, water and protein.
Micro: vitamins and minerals fribre

Question 2

Outline the functions
of macronutrients and
micronutrients

Answer 2

Carbohydrates: Fuel, energy storage, cell membrane, DNA, RNA
Lipids (Fats): Fuel, energy storage, cell membrane, hormones, precursor of bile acid
Protein: Structure, transport, communication, enzymes, protection, fuel
Water: Medium for biochemical reactions, transport, excretion
Vitamins: Energy release from macro units, metabolism, bone health, blood health, eyesight
Minerals and trace elements: Minerlizations of bones and teeth, blood oxygen transport, defense against free radicals, muscle function

Question 3

State the chemical
composition of a glucose
molecule

Answer 3

C, H and O (1:2:1 ratio)

Question 4

Identify a diagram
representing the basic
structure of a glucose
molecule.

Answer 4

c6h12o6

Question 5

Explain how glucose
molecules can combine
to form disaccharides and
polysaccharides

Answer 5

Condensation reaction—the linking of a
monosaccharide to another monosaccharide,
disaccharide or polysaccharide by the removal of a
water molecule.

Question 6

State the composition of a
molecule of triacylglycerol.

Answer 6

Triglycerides are made up of a glycerol molecule and 3 fatty acid chains.

Question 7

Distinguish between
saturated and unsaturated
fatty acids

Answer 7

Saturated fatty acids have no double bonds between the individual carbon atoms of the fatty acid chain.

Saturated fats originate from animalsources, for example, meat, poultry, full-fat dairyproducts and tropical oils, such as palm and coconut oils.

Unsaturated fatty acids contain one or more double bonds between carbon atoms within the fatty acid chain.

Unsaturated fats originate from plant-based foods, for example,
olive oil, olives, avocado, peanuts, cashew nuts, canola oil and seeds, sunflower oil and rapeseed.

Unsaturated vs Saturated
- Unsaturated vs Saturated

Unsaturated

have one or more bond between their carbon atoms

liquid at room temperature

from plant-based foods
ex. oil

Unsaturated fatty acids contain one or more double bonds between carbon atoms within the fatty acid chain. Unsaturated fats
originate from plant-based foods, for example, olive oil, olives, avocado, peanuts, cashew nuts, canola oil and seeds, sunflower oil and rapeseed.

## **Monounsaturated Fatty acid (MUFA) = single double bond**

## **Polyunsaturated Fatty Acid (PUFA) = multiple double bonds**

Saturated Fat

- have no double bonds between their carbon atoms, only single bonds
- solid at room temperature
- from animal sources
ex. meat, dairy and tropical oils such as coconut
- Saturated fatty acids have no double
bonds between the individual carbon
atoms of the fatty acid chain.
Saturated fats originate from animal
sources, for example, meat, poultry,
full-fat dairy products and tropical
oils, such as palm and coconut oils.

Question 8

State the chemical
composition of a protein
molecule

Answer 8

C H O N

Question 9

Distinguish between an
essential and a non-essential
amino acid.

Answer 9

9 Essential amino acids cannot be synthesized by the human body and must be obtained from diet.
11 Non-essential amino acids can be synthesized by the human body

Question 10

Describe current
recommendations for a
healthy balanced diet.

Answer 10

45–65 % carbohydrate, primary energy
10−35 % fat
20−35 % protein
- reduce daily sodium intake
- keep trans fatty acid consumption as low as possible
- reduce the intake of calories from solid fats and added sugars
- choose a variety of protein foods (seafood and beans)
- adequate water consumption
carbohydrates provide 4 calories per gram / 1760 kJ per 100 grams ✔
proteins provide 4 calories per gram / 1720 kJ per 100 grams ✔
fats provide 9 calories per gram / 4000 kJ per 100 grams ✔
recommendations vary by …✔
calorie intake should be 2000–3000 for males and 1600–2400 females ✔
there is much contention about recommended ranges ✔

Question 11

State the approximate
energy content per 100 g
of carbohydrate, lipid and
protein.

Answer 11

per 100 g are: carbohydrate 1760 kJ, lipid 4000 kJ and protein 1720 kJ.

Question 12

Discuss how the
recommended energy
distribution of the dietary
macronutrients differs
between endurance athletes
and non-athletes.

Answer 12

Athletes eat more

Explain the differences in dietary recommendations for a runner during marathon training and a sedentary individual both with healthy body mass index (BMI).

has a high training volume and therefore have a much higher recommendation for carb intake;

need some fat stores increase in fat

need to recover after activity and are recommended a higher protein intake;

thermoregulate more higher water/ electrolyte intake;

greater mineral and vitamin intake for bone strength/blood cell

Question 13

Outline metabolism,
anabolism, aerobic
catabolism and anaerobic
catabolism.

Answer 13

Metabolism: All the biochemical reactions thatoccur 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

Aerobic Catabolism: with the involvement of oxygen
eg glucose to ATP, water, carbon dioxide, heat via krebs cycle and electron transport chain. (aerobic glycolysis)

Anaerobic Catabolism: without the involvement of oxygen.
eg glucose to ATP, pyruvate, lactate, hydrogen ions (anaerobic glycolysis)

Glycogenesis - glucose to glycogen

Lipolysis - the breakdown of stored lipids into glycerol and fatty acids

Glycogenolysis - the breakdown of glycogen back into glucose so it can be released into the
blood

Glycogen - glucose Stored in the liver and muscles, it is a polysaccharide made out of glucose

Question 14

State what glycogen is and
its major storage sites.

Answer 14

• Highly branched chain of glucose monomers
• energy storage in animals liver and muscle

Question 15

State the major sites of
triglyceride storage.

Answer 15

Adipose tissue and skeletal muscle

Question 16

Explain the role of insulin in
the formation of glycogen
and the accumulation of
body fat.

Answer 16

1. After eating the blood glucose concentration increases
2. stimulating the pancreas to secrete insulin from it’s
   beta cells.
3. Insulin increases the transport of glucose into the cell by the translocation of the glucose transporters from within the cell to the surface of the cell.
4. Insulin stimulates glycolysis - glucose to pyruvate to lower the blood glucose levels after a meal.
5. It promotes glycogenesis (glucose to glycogen) It promotes protein synthesis.

Insulin inhibits:
6. gluconeogenesis (conversion of lactate, protien or fat to glucose)
7. lipolysis in fat stores and the break down of protiens

Question 17

Outline glycogenolysis and
lipolysis.

Answer 17

Glycogenolysis is the catabolic process of breaking down glycogen into glucose to provide a source of energy. This process primarily occurs in the liver and muscle tissues. involves a hydrolysis reaction. can be glucagon. insulin inhibits glycogenolysis. requires enzymes for optimal function.

Lipolysis
Lipolysis is the metabolic pathway through which triglycerides are broken down into glycerol and free fatty acids. This process occurs primarily in adipose (fat) tissue and is crucial for mobilizing stored energy.

Glycogenolysis: Breakdown of glycogen into glucose, mainly in the liver and muscles, to provide energy.

Lipolysis: Breakdown of fats (triglycerides) into fatty acids and glycerol, primarily in fat cells, for energy use.

Question 18

Outline the functions of
glucagon and adrenaline
during fasting and exercise.

Answer 18

Adrenaline:
1. stimulate glycogenolysis ;
stimulate lipolysis ;

2. block glucose storage by the muscles;
   facilitate sympathetic nervous activity within the body;
3. increase heart rate/cardiac output/contractility of the heart;
   increase vasodilation of blood vessels within the muscles;

glucagon:
1. produced by the pancreas / alpha cells and released into the blood stream ✔
2. is released when blood glucose levels are too low ✔

3. promotes glycogenolysis / gluconeogenesis / lipolysis ✔

Question 19

Explain the role of insulin
and muscle contraction
on glucose uptake during
exercise.

Answer 19

1. insulin and muscle contraction stimulate glucose uptake from the
   blood into skeletal muscle
2. insulin production is a response to high blood sugar/glucose levels ✔

3.insulin and muscle contractionstimulates glucose uptake from the blood into skeletal muscle
OR
insulin and muscle contraction improves cell membrane permeability to glucose ✔

4. increased sensitivity leads to decreased insulin/glycogen production ✔
   insulin:
   made by the pancreas/beta cells ✔
5. is released into the blood stream to affect many cells ✔
6. is released when blood glucose levels are high ✔
7. allows cells (muscle, liver, fat) to take up glucose / glycogenesis / lipogenesis✔

Question 20

Annotate a diagram of
the ultrastructure of a
generalized animal cell

Answer 20

The diagram should show ribosomes, rough endoplasmic reticulum, lysosomes, Golgi apparatus, mitochondrion and nucleus.

Question 21

Annotate a diagram of
the ultrastructure of a
mitochondrion.

Answer 21

Cristae, inner matrix and outer smooth membrane.

Question 22

Define the term cell
respiration.

Answer 22

Cell respiration is the controlled release of energy in the form of ATP from organic compounds in cells

Question 23

Explain how adenosine can
gain and lose a phosphate
molecule.

Answer 23

Energy is released when an ATP molecule is combined with water and ATPase. the process of phosphorylation - adding a phosphate group and dephosphorylation removing. from catabolism muscles have about 2 seconds of atp

Adenosine gains a phosphate through phosphorylation by enzymes like ATP synthase. It loses one through hydrolysis, releasing energy when the bond breaks (e.g., ATP to ADP).

Question 24

Explain the role of ATP in
muscle contraction.

Answer 24

1. the breakdown of ATP to adenosine
   diphosphate (ADP) releasing a phosphate molecule, which provides energy for muscle contraction myosin heads use the breakdown of ATP to trigger the contraction process ✔
2. the breakdown of ATP to ADP releases phosphate molecule ✔
3. the release of a phosphate molecule provides the energy for muscle contraction ✔
4. ATP reattaches to the myosin head and this causes the detachment of the crossbridge ready for the next phase if necessary ✔
5. during sprinting the ATP will come from stores (2 seconds approximately) / fromthe ATP-PC system ✔
6. depending on the length of the sprint the lactic acid process will provide sources ofATP ✔

Question 25

Describe the re-synthesis of
ATP by the ATP–CP system

Answer 25

Creatine phosphate (CP), a high energy molecule, is broken down to provide a phosphate molecule for the re-synthesis of ATP that has been utilized
during the initial stages of exercise
1. creatine phosphate/CP/PCr is a high-energy molecule/fuel ✔
2. speed of breakdown is increased by creatine kinase ✔
3. CP is broken down to provide a phosphate molecule for the re-synthesis of ATP/ energy released is used to add Pi to ADP «endothermic reaction» ✔

4. reaction is a coupled reaction where one reaction is linked to another reaction ✔
5. releases energy «exothermic reaction» and phosphate molecule/Pi ✔
   1 PC = 1ATP✔ does not require oxygen✔
6. is the first system to provide ATP / occurs in the first 10–15sec of exercise✔

Question 26

Describe the production of
ATP by the lactic acid system.

Answer 26

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
(two ATP molecules).
1. system can only use glycogen/glucose as a fuel source;
glucose is converted into pyruvate;

2. system produces a low yield / 1 glucose produces 2ATP ;
3. in the absence of oxygen pyruvate is converted to lactate/lactic acid;
4. byproducts of lactic acid system are lactic acid, <hydrogen ions, lactate>; system resynthesizes ATP at a rapid rate;

Question 27

Explain the phenomena of
oxygen deficit and oxygen
debt. ()

Answer 27

DEFECIT:
1. when exercise begins, the aerobic system cannot supply the required energy;
2. anaerobic systems <ATP–PC, lactic acid> meet the shortfall;
3. oxygen demand is greater than oxygen supply;
4.deficit increases during final sprint;
Post-exercise oxygen consumption/EPOC/oxygen debt takes place because there is a need for:
breathing remains elevated until recovery is complete ✔

EPOC is paying back the oxygen deficit during the initial energy demands achieved by the anaerobic systems ✔

reformation of phosphocreatine ✔

replenishment of myoglobin stores ✔

removal of lactic acid ✔

replenishment of glycogen stores «up to 24 hours» ✔

a highly trained aerobic athlete returns to a steady state quicker than untrained
OR
a highly trained aerobic athlete has a smaller EPOC than untrained ✔
Oxygen deficit:
because oxygen needs and oxygen supply differ during the transition from rest to exercise your body incurs an oxygen deficit
OR
occurs when exercise/aerobic work is above the requirement for oxygen at rest✔

the oxygen deficit is calculated simply as the difference between the oxygen required for a given rate of work and the oxygen actually consumed✔

when exercise commences abruptly the demand for ATP is immediate✔

the initial energy is met with ATP stores✔

in spite of insufficient oxygen, your muscles still generate the ATP needed through the anaerobic pathways✔

oxygen deficit creates an oxygen debt which is paid back after exercise✔
oxygen deficit:
as exercise commences the breathing rate increases/an oxygen deficit is incurred ✔

oxygen deficit may further increase as a result of walking up inclines and vice versa ✔

ATP will be supplied via anaerobic pathways ✔

at a steady submaximal level there will be a plateauing of breathing rate and heart rate ✔

PC stores can be resynthesized during steady state ✔

oxygen debt:
at the end of the hike, the walkers breathing rate remains elevated
OR
at the end of the hike, excess post-exercise oxygen consumption occurs
OR
oxygen deficit is paid back after exercise/oxygen debt ✔

the greater the oxygen deficit the greater the oxygen debt✔

ATP/ PC stores are replenished ✔

myoglobin/ hemoglobin are reoxygenated ✔

phosphagen stores and myoglobin stores can be replenished within a few minutes of recovery <alactacid/fast component> ✔

aerobically metabolize lactic acid
OR
resynthesize lactate to glycogen ✔

replacement of muscle/liver glycogen stores ✔

the recycling/removal of lactate and replenishment of glycogen stores may take several hours after exercise <lactacid/slow component> ✔

Oxygen debt (EPOC):
1. oxygen consumption is elevated / EPOC after the event ;
2.will remain high until carbon dioxide and lactic acid levels return to normal;
3. restoration of PC;
4. EPOC can be divided into the fast/alactacid component where PC is restored and the slow/lactacid component where metabolic by-products are removed;
at the end of the race, the athlete’s breathing rate remains elevated
OR
excess post-exercise oxygen consumption occurs during recovery ✔

the greater the intensity of the race the greater the EPOC/oxygen debt ✔

ATP/ PC stores are replenished ✔

myoglobin / hemoglobin are reoxygenated ✔

phosphagen stores and myoglobin stores can be replenished within a few minutes of recovery <alactacid/fast component> ✔

aerobically metabolize lactic acid
OR
resynthesize lactate to glycogen ✔

replacement of muscle / liver glycogen stores ✔

the recycling/removal of lactate and replenishment of glycogen stores may take several hours after exercise <lactacid/slow component> ✔
the greater the intensity of the exercise, the greater the EPOC;

initial stages of exercise, oxygen demand cannot be met by the aerobic system
OR
initial stages are met by anaerobic processes;

oxygen deficit is paid back after exercise/oxygen debt;

alactacid/fast component is replenished with the first few minutes
OR
alactacid/fast component requires relatively less oxygen compared to the lactacid/slow component;

ATP and CP/PC stores are replenished;

myoglobin oxygen levels are replenished;

aerobically metabolize lactic acid;

resynthesize lactate to glycogen;

replacement of muscle / liver glycogen stores;
deficit is calculated as the difference between the oxygen required for a given rate of work and the oxygen actually consumed
OR
deficit takes place during the initial stages of exercise;

muscles generate ATP through anaerobic pathways;

oxygen transport system is not immediately able to supply the needed quantity of oxygen to the active muscles
OR
oxygen consumption requires several minutes before a homeostatic level is reached;

homeostatic level is reached when the aerobic system meets the demands;

the greater the intensity of exercise, the greater the oxygen deficit;

deficit is repaid during rest period/after exercise;

oxygen deficit can be minimised by the athlete doing a warm-up;

if the exercise intensity is too high the athlete will have to stop exercising or reduce their intensity;

trained individuals may have a smaller deficit/smaller EPOC compared to an untrained individual at the same intensity;
deficit is calculated as the difference between the oxygen required for a given rate of work and the oxygen actually consumed ✔

deficit takes place during the initial stages of exercise ✔

muscles generate ATP through anaerobic pathways ✔

oxygen transport system is not immediately able to supply the needed quantity of oxygen to the active muscles
OR
oxygen consumption requires several minutes/time before a homeostatic level is reached ✔

homeostatic level is reached when the aerobic system meets the demands ✔

is repaid after exercise is finished✔
deficit is calculated as the difference between the oxygen required for a given rate of work and the oxygen actually consumed
OR
deficit takes place during the initial stages of exercise;

muscles generate ATP through anaerobic pathways;

oxygen transport system is not immediately able to supply the needed quantity of oxygen to the active muscles
OR
oxygen consumption requires several minutes before a homeostatic level is reached;

homeostatic level is reached when the aerobic system meets the demands;

the greater the intensity of exercise, the greater the oxygen deficit;

deficit is repaid during rest period/after exercise;

oxygen deficit can be minimised by the athlete doing a warm-up;

if the exercise intensity is too high the athlete will have to stop exercising or reduce their intensity;

trained individuals may have a smaller deficit/smaller EPOC compared to an untrained individual at the same intensity;
The greater the intensity of the exercise, the greater the EPOC ✔

initial stages of exercise, oxygen demand cannot be met by the aerobic system
OR
initial stages are met by anaerobic processes ✔

oxygen deficit is paid back after exercise/oxygen debt ✔

alactic/fast component is replenished with <3–4 litres of> oxygen ✔

ATP and CP/PC stores are replenished ✔

myoglobin oxygen levels are replenished ✔

aerobically metabolize lactic acid ✔

resynthesize lactate to glycogen ✔

replacement of muscle / liver glycogen stores ✔

Question 28

Describe the production of
ATP from glucose and fatty
acids by the aerobic system ()

Answer 28

Limit to: in the presence of oxygen, pyruvate is processed by the Krebs cycle which liberates electrons that are passed through the electron transport chain producing energy (ATP). Fats are also broken down by beta oxidation that liberates a greater number of electrons, thus more ATP. In the presence of oxygen, and in extreme
cases, protein is also utilized the aerobic energy system / aerobic glycolysis involves three processes: glycolysis, Krebs cycle, electron transport chain✔
glycolysis takes place in the cell cytoplasm / outside the mitochondria✔
Krebs cycle and electron transport chain takes place in mitochondria✔
the aerobic energy system can produce ATP from all the main food groups of our diet✔
it involves the production of ATP with oxygen✔
in the presence of oxygen, pyruvate is processed by the Krebs cycle which liberates electrons that are passed through the electron transport chain producing energy ‹ATP›✔
the oxidative system of energy production can generate up to 38 molecules of ATP from one molecule of glucose✔
Glucose oxidation:
during glycolysis glucose is firstly phosphorylated which uses up 2ATP✔
glucose is split into two pyruvate molecules during glycolysis, <which regenerates 4ATP>✔
glycolysis generates a net production of 2ATP✔
during aerobic production of ATP pyruvate is converted to acetyl CoA which enters the Krebs cycle / which generates 2 ATP✔
CO2 and hydrogen ions are released from the Krebs cycle✔
hydrogen ions are carried to the electron transport chain where energy and water are produced / which produces 34 ATP✔
fats are broken down during beta (β) oxidation ✔
fatty acids are broken down into acetyl CoA ✔
acetyl CoA enters the Krebs cycle ✔

Question 29

Discuss the characteristics
of the three energy
systems and their relative
contributions during
exercise. ()

Answer 29

Limit to:
* fuel sources
* duration
* intensity
* amount of ATP production and by-products.

Question 30

Evaluate the relative
contributions of the three
energy systems during
different types of exercise. ()

Answer 30

relative contributions of the energy systems will be determined by the skill and fitness of the opposition / breaks in play/ pace of the game✔

relative contributions of the energy systems will be determined by the position of the player✔

relative contributions of the energy systems will be determined by the individual’s fitness level✔

ATP–PC:
short duration ‹one to ten seconds› at maximal intensity✔

fuel source Creatine Phosphate✔

no fatigue causing by-products✔

eg sprinting to stop an attacking move by opposition; goal kicker diving to save goal✔

Lactic acid:
moderate duration at a high intensity, between 20 seconds to two minutes✔

fuel source is anaerobic glycolysis/ glucose✔

lactic acid is a fatigue causing by-product and will see cessation of activity or reduced intensity✔

eg broken play up and down field for 20 + seconds✔

Aerobic:
play at lower intensity✔

fuel source is aerobic glycolysis/ glucose, fat and protein✔

no fatigue causing by-products✔

duration can continue as long as fuel supply exists✔

eg passing and low intensity play off ball✔