Muscles: fibres, training, fatigue Flashcards
List the 3 methods of ATP production
Direct phosphorylation
Glycolysis
Oxidative phosphorylation
Which methods of ATP synthesis provides energy the fastest ?
Direct phosphorylation
Which methods of energy production has the shortest and longest supply of energy
Shortest supply: direct phosphorylation
Longest supply: oxidative phosphorylation (good for endurance activities)
Describe direct phosphorylation, where it occurs and how long it provides energy for?
Involves creatine phosphate + ADP to form creatinine and ATP. Creatine is delivered to muscles via the bloodstream.
CreaTININE is a waste product which is carried way by blood tot the kidneys.
It occurs in the cytoplasm and provides energy for 10 seconds.
What factors limit creatine phosphate production?
If creatine is digested and not absorbed into the bloodstream
If creatine is absorbed but does not enter the correct cell
Creatine may not be properly modified to produce creatine phosphate.
Describe glycolysis, where it occurs, conditions it occurs in and how long it provides energy for?
Glycolysis is an anaerobic process whereby glucose is converted into 2 molecules of pyruvate. 2 ATP are used up and 2NADH and 4 ATP are produced. Net gain = 2ATP + 2NADH.
It occurs in the cytoplasm and can provide energy from 30 seconds up to 2 minutes.
Describe oxidative phosphorylation, including rate of energy production, where it occurs, conditions and how long it provides energy for
The most efficient energy production method but requires oxygen. It produces energy slowly but energy can last up to 3 hours.
Involves the:
Kreb’s cycle which occurs in the matrix of mitochondria
Electron Transport Chain: occurs in the inner membrane of the mitochondria.
Describe the process of oxidative phosphorylation, involving the prep step, kerb’s cycle and ETC
Prep step: Each Pyruvate is converted into acetyl co-enzyme A, which produces 2NADH and 2CO2.
Kreb’s cycle: acetyl co-enzyme A combines with oxaloacetate to form citric acid. This produces 1 FADH, 3NADH, 2CO2 and 1 GTP molecule.
ETC: Electron carriers migrate to inner mitochondrial membrane. High energy electrons are released from NADH and FADH and they move along the electron transport chain. Their energy is captured and used pump H+ ions across the inner membrane and into the intermembrane space.
The pumping of ions creates a build up of H+ ions in the intermembrane space. They diffuse back across the membrane through ATP synthase, generating ATP.
The electrons combine with oxygen to produce water.
What are the 3 main types of motor units?
Type 1 (slow) Type 2a (fast fatigue resistant) Type 2b/x (fast fatigue)
What are the types of motor units classified according to?
Speed of contraction and fatigue rate
How do the uses of the type 1 and 2 motor units differ?
Type 1: helps with endurance activities
Type 2: used for quick, short bursts of movement
Describe type 1 (slow) motor units according to: resistance to fatigue, oxidative capacity, contraction speed, colour, cell contents, motor neuron size motor neuron conduction velocity
Highest resistance to fatigue High oxidative capacity Fastest contraction speed Red Many mitochondria = more aerobic capacity Smaller motor neurone Slow motor neuron conduction velocity
Describe type 2a (fast fatigue resistant) motor units according to: oxidative capacity, contraction speed, colour, cell contents, motor neuron size motor neuron conduction velocity
Higher oxidative capacity than 2b Slower contraction speed than type 1 Red in colour More developed sarcoplasmic reticulum so is better at delivering calcium to muscle cells when stimulated. larger motor neurone faster motor neuron conduction velocity
Describe type 2b (fast fatigue) motor units according to: oxidative capacity, contraction speed, colour, cell contents, motor neuron size motor neuron conduction velocity
Low oxidative capacity as they rely on aerobic glycolysis
Slower contraction speed
White - use anaerobic respiration so have low oxygen supply
More developed sarcoplasmic reticulum than type 1
Larger motor neurone size
faster motor neuron conduction velocity
Out of the 3 motor unit types, which one has the highest number of fibres per motor neuron?
Type 2a
