P1 - Energy systems

Question 1

What is ATP?

Answer 1

ATP is the only USABLE form of energy in the body

When ATP is broken down energy is provided for cellular processes, such as muscle contraction, digestion and nerve transmission.

Question 2

What is a exothermic and a endothermic reaction?

Answer 2

Exothermic is where energy is released and endothermic is where energy is absorbed.

Question 3

Explain the breakdown off ATP? what enzyme? what type off reaction? which bond breaks off? what’s left over?

Answer 3

To extract the energy from ATP, the enzyme ATPase is released which breaks the final high energy bond.

This exothermic reaction releases energy, leaving ADP + P and energy.

Question 4

Without resynthesise how long does it take to use atp stores? what 3 systems are used to re syntheise ATP?

Answer 4

The ATP stores are used quickly (2-3 secs).

ATP-PC System
Glycolytic (lactic acid) System
Aerobic System

Question 5

How does the ATP-PC System (Anaerobic) work? what fuel do we depend on next? What enzyme? What’s the term given to the double reaction? What’s the ratio of ATP released for every ATP resynthesized?

Answer 5

ATP stores are used up within 2-3 seconds & we then depend on our next source - Phosphocreatine (PC).

ATP stores fall and ADP and P levels rise.This triggers the release of creatine kinase, an enzyme which catalyses the breakdown of the fuel phosphocreatine (PC).

Where the breakdown of PC releases a free phosphate and energy which is used to resynthesise ATP.

This is called a coupled reaction: This is where the products of one reaction are used by another.

1 mole of ATP is released for every ATP resynthesized (Ratio of 1:1).

Question 6

What is PC? where is it broken down? what enzyme?

Answer 6

PC is made up of creatine & a high-energy phosphate bond and is stored in the muscle.
This is broken down quickly in the sarcoplasm by creatine kinase.

Question 7

How long do PC store last? in total how long can the ATP - PC system be used for?

Answer 7

PC stores are also small and are depleted after approximately 8 seconds.

10secs

Question 8

What are the advantages of the ATP PC system?( anaerobic)

Answer 8

Provides ATP quickly
Provides energy for fast, high intensity activities.
No harmful by-products
PC readily available in muscle cell
No delay for oxygen

Question 9

What are the disadvantages of the ATP - PC system?

Answer 9

Only a small amount of PC stored in muscle cells
Small amount of ATP is resynthesized (1 mole)
Only provides energy for maximum of 8-10 seconds

Question 10

when does the Glycolytic
(Lactic acid) System work? As ADP and P levels rise what does it trigger the release of? What does PFK do, whats the name off this process? when glucose levels dip what enzyme catalyses the breakdown off stored glycogen?

Answer 10

Kicks in during high-intensity exercise after 10 seconds, when PC and ATP stores are exhausted.

ADP and P levels rise and trigger the release of the enzyme phosphofructokinase (PFK),This catalyses the breakdown of the next available fuel source: Glucose. This breakdown of glucose (without oxygen) is through a process called anaerobic glycolysis. Which results in the making off pyric acid

If glucose levels dip, glycogen phosphorylase (GPP), an enzyme which catalyses the breakdown of stored glycogen (muscles and liver), is released, converting glycogen into glucose.

Question 11

Where does the glycolytic system take place? What’s the resynthesizes of ATP to mole of glucose ratio? how long does it last? when is peak efficiency?

Answer 11

Takes place in the sarcoplasm of the muscle cells.
Resynthesizes 2 ATP for every 1 mole of glucose (1:2)

Lasts for around 3 minutes, though peak efficiency is at 1 minute

Question 12

What does pyric acid get turned into? What enzyme?

Answer 12

LDH is an enzyme which converts pyruvic acid into lactic acid.

Question 13

What is lactic acid and what does lactic acid do?

Answer 13

Lactic acid is produced by the glycolytic system during intense physical activity due to a lack of oxygen availability.
Inhibits/denatures enzyme action & decreases ATP resynthesis.
causes fatigue.
As lactate levels rise, pH levels drop in the muscle and inhibit enzyme activity.
OBLA (onset blood lactate accumulation) is at 4 mmol/L.

Question 14

What is OBLA

Answer 14

Onset of Blood Lactate Accumulation (4mmol/l)

‘The point at which blood lactate levels significantly increase and fatigue sets in’.

Question 15

What are the impacts of aerobic training?

Answer 15

can increase the body’s tolerance to lactic acid & increase glycogen stores.

Question 16

When is the aerobic system dominant? how much potential energy of the body in glucose does it hold?

Answer 16

dominant during low-moderate activities, as oxygen is available and enables continued energy production

This system utilizes 95% of the potential energy in glucose,

Question 17

Explain aerobic glycolysis from pyruvic acid al the way to citric acid?

Answer 17

As enough O2 is available, pyruvic acid is no longer converted to lactic acid

It goes through a link reaction catalysed by the enzyme coenzyme A, which produces acetyl CoA.

Acetyl CoA combines with oxaloacetic acid to form Citric Acid

Question 18

explain how the kreb cycle works, where? whats released?

Answer 18

citric acid enters the Kreb’s Cycle and is oxidised through a series of chemical reactions.

CO2, hydrogen and enough energy to resynthesise 2 ATP to be released. Also causes the regeneration of oxalectici acid
Occurs in the matrix (intracellular fluid) of the mitochondria.

Question 19

What then happens to the hydrogen ions and electrons? (electron transport chain)? how many moles produced?

Answer 19

The Hydrogen atoms are carried to the ETC (along the cristae of the mitochondria) by NAD and FAD (hydrogen carriers)

They split into H+ ions and H- electrons

Hydrogen ions are oxidised and removed as H2O

Pairs of hydrogen electrons are carried by NAD (NADH2) and release enough energy to resynthesise 30 moles of ATP

Those carried by FAD (FADH2) (ions) release enough energy to resynthesise 4 moles of ATP

Question 20

How do triglycerides come into the energy system? what enzyme breaks it down to free fatty acids and glycerol?

Answer 20

So, triglycerides (fats) can be metabolised aerobically as Free Fatty Acids (FFAs), caused by the release of the enzyme lipase

Lipase converts triglycerides into Free Fatty Acids (FFAs) and glycerol.
FFAs are converted to acetyl CoA and enters the Kreb’s Cycle and ETC chain

Question 21

what is beta oxidation of free fatty acids? how much more oxygen to metabolise? why is it preferable for endurance events?

Answer 21

Free Fatty Acids are also used as fuel, in a process known as beta-oxidation.
This has a high energy yield/value and preserves glycogen stores.
FFAs require approximately 15% more oxygen to metabolise, so will only occur when exercise intensities are lower.
FFAs produce more acetyl CoA and have a higher energy yield, so this is preferable for endurance events.

Question 22

whats the total ATP yeild of all 3 systems?

Answer 22

38

Question 23

What is the energy continuum?

What is the dominant system dependant on?

Answer 23

‘The relative contribution of each energy system to physical activity’.
All systems are contributing but the dominant system is dependent on intensity and duration of activity.

Question 24

what are training adaptations that help delay OBLA?

Answer 24

more myogolbin. more mitrochodnria. more areobic enzymes. more effecicent cv system. more haemoglobin. more elesatic blood aertrial walls. increased uptake of 02 at muscles.