4: energy systems Flashcards
What is every?
the ability to do work
What are the three energy systems?
- Immediate; ATP-PC; Alactic
- Short term; NON-oxidative; lactic
- Long term; Oxidative; Aerobic
What are the three ways to produce ATP?
1) formation of ATP by Phosphocreatine (PC) breakdown
2) formation of ATP by degradation of glucose/glycogen
3) Oxidative Phosphorylation
What is the high energy phosphate system?
high energy phosphate system
immediate
What is ATP - PC (alactic system)
used for rapid, short term muscle movement
1) stored ATP
- varies with fibre type and training; depletion; measurement
2) the ATP derived from PC + ADP
Creatine Phosphate
1) high energy phosphate store
2) buffer of ATP/ADP ratio
3) a high energy transporter
Phosphocreatine: Energy reservoir
anaerobic resynthesis of ATP
hydrolyzed by the enzyme, creatine kinase
ADP is phosphorylated to ATP
Creatine may be phosphorylated back to PCr
cells store ~ 4 - 6 times more PCr than ATP
Creatine
increases muscle PC stores
important component of high energy phosphates
documented benefits in humans:
- improve muscular strength and power; augments short bursts of muscular endurance; enables greater muscular overload
limited research on potential risks
creatine loading
What type of fibres are affected by creatine?
both type I and II fibres but >type II (high intensity)
high dosages not necessary at start
can maintain on 3 g/day
increase performance for exercise 30 sec or less
What is the primary energy source for high energy phosphate system?
Stored ATP, CP
high energy phosphate system:
What is the duration of activity?
7-12sec
high energy phosphate system:
What are the sporting events?
quick bursts sports
weight lifting, high jump, long jump, 100m run, 25m swim
high energy phosphate system:
What are the advantages?
produce very large amount of energy in a short amount of time
high energy phosphate system:
What is the disadvantages?
initial concentration of high energy phosphates (ATP, PC)
Anaerobic Glycolytic System
starts when:
- the reserves of high energy phosphate compounds fall to a low level
the rate of glycolysis is high and there is build-up of pyruvic acid
Glycolysis
a biochemical process that release energy in the form of ATP from glycogen and glucose anaerobic process (in the absence of oxygen)
What are the products of glycolysis?
2 molecules of ATP
2 molecules of pyruvic acid (fate 1)
What are the by-product of glycolysis
2 molecules of lactic acid (fate 2)
how many ATP is produce from NADH?
3 ATP molcules
how many ATP is produce from FADH?
2 ATP molecules
Fate 2a
pyruvate can be reduced to lactate; process consumes NADH; NAD+ is generated
this generates ATP more rapidly but less ATP is generated and lactate and H+ are also generated
when oxygen availability is low but high ATP demand is needed
Fate 2b:
aerobic pyruvate enters the mito and reacts with CoA to form AcetylCoA (and CO2) which enters the Krebs/ETC –> slow glycolysis or aerobic glycolysis)
Anaerobic glycolytic system:
what is the primary energy source?
stored glycogen, blood glucose
Anaerobic glycolytic system:
What is the duration of activity?
12s - 3min
Anaerobic glycolytic system:
what are the type of sporting events
800m run, 200m swim, downhill ski racing, 1500 speed skating
Anaerobic glycolytic system:
What are the advantages of this?
ability to produce energy under conditions of inadequate oxygen
Anaerobic glycolytic system:
what are the limiting factors?
lactic acid build up, H+ ions build up (decrease of pH)
The aerobic oxidative system
the most important E system in the human body
primary source of energy (70-95%) for exercise lasting longer than 10 mins
primary source of energy: performed at an intensity lower than that of anaerobic oxidative system
What are the two paths of oxidatiev phospohrylation system?
krebs cycle and ETC
how much energy is yielded from 1 molecule of glucose?
36/38 ATP molecules
how much energy is yielded from 1 molecule of fat?
169 atp molecules
What ar ethe byproducts of oxidative phosphorylation?
co2, water
how many by - products are made in krebs
1 ATP, 3 nadh, 1 fadh2, 1 co2
Aerobic Oxidative System:
what are primary energy sources?
glycogen, glucose, fats, proteins
Aerobic Oxidative System:
what is the duration period?
> 3mins
Aerobic Oxidative System:
what type of sporting events?
walking, jogging, swimming, walking up stairs
Aerobic Oxidative System:
what are the advantages:
large output of energy over a logn period of time, removal of lactic acid
Aerobic Oxidative System:
what are the limiting factors?
Lung function, max bf, oxygen availability, excess energy demands
What are slow twitch fibres?
type I; slow oxidative; very red!; muscular always working high resistance to fatigue used for long durations low energy
What are fast twitch fibres?
type IIa = fast oxidative glycolytic type IIx/b = fast glycolytic only is active for heavy or higher events very white short duration sports fast contraction rates high energy
What is EPOC?
the afterburn
a measurable increased rate of oxygen intake following strenuous activity intended to erase the body’s “oxygen deficit”
