Unit 3: Energy Systems

Question 1

List the micronutrients and macronutrients:

Answer 1

Micro → vitamin and mineral
macro → Lipid (fat), carbohydrate, water and protein.

Question 2

state the chemical composition of a glucose molecule

Answer 2

The molecular formula of glucose is C6H12O6 (1:2:1 ratio)

Question 3

Glucose molecules can combine to form…

Answer 3

polysaccharides and disaccharides

Question 4

What si the condensation reaction?

Answer 4

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

Question 5

State the composition of a
molecule of triacylglycerol.

Answer 5

1 glycerol and 3 fatty acids

Question 6

State the chemical composition of a protein molecule.

Answer 6

C, H, O, and N.

Question 7

Outline metabolism

Answer 7

All the biochemical reactions that
occur within an organism, including anabolic and
catabolic reactions.

Question 8

outline anabolism

Answer 8

Energy requiring reactions whereby
small molecules are built up into larger ones.

Question 9

outline catabolism

Answer 9

Chemical reactions that break down
complex organic compounds into simpler ones, with the net release of energy.

Question 10

State what glycogen is and
its major storage sites.

Answer 10

Glycogen is stored glucose. It is stored in the liver and the skeletal muscle.

Question 11

State the major sites of
triglyceride storage.

Answer 11

Adipose tissue and muscle

Question 12

Outline glycogenolysis.

Answer 12

The break down of glycogen into glucose

Question 13

Outline lipolysis.

Answer 13

The breakdown of lipids into glycerol and fatty acids.

Question 14

Define cell respiraton

Answer 14

the controlled release of energy in the form of adenosine triphosphate (ATP) from organic compounds in cells.

Question 15

Distinguish between an essential and a non-essential amino acid (2)

Answer 15

Essential amino acids: cannot be synthesized by the human body and must be obtained from diet

Non-essential amino acids: can be synthesized by the human body

Question 16

Define balanced diet

Answer 16

Balance diet: diet that provides all nutrients in the right amount in order to maintain health and prevent nutrient excess or deficiency diseases.

Question 17

Describe current recommendations for a healthy balanced diet (6)

Answer 17

carbs: 45-65% NA | A 55-75% (+ energy)
lipids: 15-30% NA | A 25-35%
proteins: 10-15% NA | A 15-35% (+ muscle)

Question 18

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

Answer 18

Carbohydrates - 1760 kJ
Lipids - 4000 kJ
Proteins - 1720 kJ

Question 19

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

Answer 19

Endurance athletes will need higher amounts energy and fluids because of the increased physicological demands. They will need higher amounts of carbs, proteins, and fats than non-athletes require. Though nutritional needs vary beween the type of sport and the periods of training, competition and recovery.

Question 20

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

Answer 20

Insulin and glucagon regulate sugar levels in the blood.
After eating a meal, there is an increase of glucose in the blood. This is a signal for the pancreas to secrete insulin from its beta cells. The insulin decreases the elevated amount of blood sugar (glucose) and increases the transport of glucose into the muscle cell.
The fast uptake of glucose inhibits the release of glucose from the liver and muscle and promotes the synthesis of glycogen in liver and muscle (leaves from the blood) to lower blood glucose levels after a meal is ingested. It inhibits gluconeogenesis (synthesis of glucose) and promotes glycogenesis (synthesis of glycogen with glucose).

Question 21

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

Answer 21

• Creatine phosphate stores provide energy for muscle contraction
• During light exercise, energy is derived from glucose
• Initially from anaerobic glycolysis (breakdown of glycogen)
• To maintain energy supply by glucose, the muscle increases the uptake of glucose by blood
• Muscle contraction stimulates the translocation of glucose transporters from the inner cell storage pool to the cell membrane but in a different way to insulin
• Insulin takes place during no exercise
• Exercise lowers insulin blood, therefore, reduces function in glucose transport

Question 22

Explain how adenosine can gain and lose a phosphate molecule

Answer 22

Phosphate groups are very energy-rich

Gain (phosphorylation): When a phosphate molecule is added back through energy, ATP can be made

Loose: ATP is combined with water it loses a phosphate molecule which results in ADP, and releasing a lot of energy

Question 23

Explain the role of ATP in muscle contraction (3)

Answer 23

• Muscle contraction requires a lot of energy.
• ADP is transformed into ATP by myosin at the myosin head, this allows the pull of the sarcomere. ATP is the energy needed for a muscle contraction to occur.
• In a muscle, there is ATP to allow 2 seconds of activity. Meaning that more exercise is using ATP from another source.
• In this case, the energy comes from some biological pathways called the energy systems (creatine phosphate, aerobic and anaerobic respiration and beta oxidation). The performance of energy systems influence the contraction of muscle. This influences our ability to exercise.

Question 24

Describe the resynthesize of ATP by the ATP–CP system (5)

Answer 24

• Creatine phosphate (ATP-CP) is a high energy chemical compound.
• This energy compound cannot be directly used during muscle contraction.
• Creatine phosphate + ADP + H = Creatine + ATP
• Creatine phosphate gives 20 seconds energy always, this does not mean stop exercising. It means that other ways should become suitable.
• Creatine phosphate + 2 seconds worth ATP muscle, dominates provision of energy when we start exercising. It is very important during fast and hard exercise.

Question 25

Describe the production of ATP by the lactic acid system

Answer 25

• Also known as anaerobic glycolisis.
• Breakdown of glucose to pyruvate without the use of oxgen.
• Pyruvate then converted into lactic acid.
• Wich limits the mount produced to 2 molecules.
• For performance of longer splits, rapid re-synthesis of ATP required using this system.

Question 26

Explain the phenomena of oxygen deficit and oxygen debt (2)

Answer 26

• Oxygen deficit: The difference between the amount of oxygen consumed during exercise and the amount that would have been consumed if aerobic respiration occurs.
• Oxygen debt also known as EPOC: EPOC: excess post-exercise oxygen consumption. Is the amount of oxygen consumed in recovery after exercise that is above resting level.

Question 27

Describe the production of ATP from glucose and fatty acids by the aerobic system. (2)

Answer 27

glucose:
- In presence of oxygen, pyruvate is processed by krebs cycle liberating electrons that are passed through the electron transport chain producing 34 ATP

fatty acids:
- broken down by beta oxidation liberating a lots of electrons, therefore more ATP
in extreme cases, proteins will also be used as a form of energy

Question 28

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Question 29

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Question 30

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Question 31

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Question 32

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Question 33

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Question 34

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Question 35

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Question 36

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Question 37

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Question 38

Outline the function of macronutrients

Answer 38

Carbohydrates: short term energy storage, cell membrane,

Lipids (Fats): long-term energy storage, hormones

Protein: Structure, transport, enzymes, protection, fuel of energy

Water: Medium for biochemical reactions, transport, excretion

Question 39

Outline the functions of micronutrients

Answer 39

Vitamins: metabolism, bone health, blood health, eyesight

Minerals: Minerlizations of bones and teeth, defense against free radicals, muscle function

Question 40

Outline anaerobic catabolism

Answer 40

Compounds breaking down in the absence of oxygen