Khamiir (Af Ingiriis : Fermentation ; Af Carabi : ar ) waa nidaamka iyo habka sonkorta loogu bedelo asiidh, neef ama alkahool. Habka khamiirintu waxaa loo isticmaala yiisti si loo dedeji nidaamka.
Nidaamka khamiirinta: xumbo CO2 oo laaqmeysa.
Macluumaadka nidaamka samaynta khamiirinta ethanol. Hal malakuyuul oo glukose ah ayaa loo kala jebiyaa labo nooc (1). The energy from this exothermic reaction is used to bind inorganic phosphates to ATP and convert NAD+ to NADH. The two pyruvates are then broken down into two acetaldehyde molecules and give off two CO2 molecules as a waste product (2). The acetaldehyde is then reduced into ethanol using the energy and hydrogen from NADH; in this process the NADH is oxidized into NAD+ so that the cycle may repeat (3).