superman or voldemort -- lactate

lactate in the anaerobic system

byproduct of the glycolytic system

steps to lactate creation

Lactate doesn’t give us energy but it

allows us to start glycolysus again

production of lactate from pyruvate recycles

NAD shuttles and prevents pyruvate from accumulating

conversion provides

recycled NAD to enable continued glycolysis

conversion of pryuvate to lactate enables

continued glycolysis

faster lactate production leads to

• higher power in 30s

• faster final sprint during 5KM time trial

more lactate =

more energy

lactate’s sidekick

H +

Acidosis

drop in PH due to the accumulation of H

Decrease in PH of the muscle (muscular acidosis) impairs

• Ca release and re-uptake into SR

• sensitivity of myofilaments to Ca+

• ATPase activity

• enzyme (PFK and phsophorylase) activity

acidosis gives (force)

32% lower max force

acidosis gives (length)

13% muscle shortening

Acidosis and CA

• more calcium is required to activate muscle but less calcium is available

acidosis and atpase activity

slower crossbridge cycling

enzyme activity and acidosis

slower metabolism

decreased PH in the muscle and systemically can lead to

• muscle soreness

• vomiting

• lightheadedness and fainting

• headache

more hydrogen =

more fatigue

lactate production enables fast

glycolytic energy

lactate production is key mechanism for

fatigue and feelings of unwell

how does lactate become the villain

once it accumulates then it becomes bad.

how lactate is created

pyruvate → lactic acid → lactate and H+

Acid-base regulation

buffering describes processes that reduce changes in H+ concentration

pertubation for acid-base regulation

• accumulation of H+ reduces PH

Adjustment for acid base regulation

buffering = the adjustments needed to restore equilibrium

buffering

the processes that reduce changes in H+ concentration

bicarbonate buffering

bicarbonate (HCO3) combines with H+ to form water and carbon dioxide

• can occur within the cytosol and or within the blood

summary of lactate clearing

• H⁺ and lactate are produced during metabolism.

• HCO₃⁻ buffers H⁺, converting it into CO₂ and water.

• CO₂ is transported by red blood cells and plasma.

• CO₂ is exhaled in the lungs, helping to maintain pH balance.

• The kidneys and liver also help remove excess lactate and H⁺.

lactate will be converted

back into pryuvate to be utilized again

conversion of pryuvate occurs

in the muscle of origin

in the liver of different muscles

pryuvate in muscle of origin

pryuvate restarts it oxidative journey

conversion back to pryuvate

• lactate is transported into the blood through monocarboxylate transporter (MCT)

  • transported in the blood to other muscles

  • transported in the blood to the liver

    • Cori Cycle

overall lactate

conversion of pyruvate into lactrate recyles NAD shuttle and enables continued glycolysis

H+ overall

generated during this conversion reduces muscle performance and contributes to fatigue

• H+ is buffered by HCO3 to produce CO2 and H20

Lactate is oxidized and/or

converted back to pyruvate in the muscle or liver