S.5 And S.6 Biology Notes Respiration (1) Caltec S.5

08 Respiration #79 Respiration realeases energy from food Respiration is the chemi cal reactions that break down nutrie nt molecules in living cells to release energy. In humans, our cells need energy (ATP) for:  muscle contraction  making protein molecules: linking together amino acids into long chains  cell division: to repair damaged tissues and so that we can grow  active transport  transmitting nerve impulses  maintenance of constant body t° All this energy comes from the food we eat. Water soluble molecules are absorbed from the intestine into the blood. The main energy –providing nutrient: glucose (contains a lot of chemical energy). There are 2 types of respiration: Video ATP & Respiration: Crash Course Biology #7 https://www.youtube.com/watch?v=00jbG_cfGuQ #80 Aerobic and anaerobic respiration Respiration releases energy from food. There are 2 kinds of respiration: Aerobic and Anearobic . The main difference between them is that aerobic respiration involves oxygen and anaerobic respiration does not! A. Aerobic respiration The release of a relatively large amount of energy in cells by the breakdown of food substances in the presence of O2. B. Anaerobic respiration Anaerobic respiration: the release of a relatively small amount of energy by the breakdown of food substances in the absence of O2. Anaerobic respiration in muscles during exercise: Anaerobic respiration in yeast: Muscles respire anaerobically when exercising vigorously, because the blood cannot supply enough oxygen to maintain aerobic respiration. Howerver, the formation and build -up of lactic acid in muscles causes cramp (muscle fatigue). The lactic acid that is made is transported to the liver, and later is broken down by combining it with O2. This extra O2 is breathed in after the exercise has stopped, and it is known as the oxygen d ebt. Bread making - yeast is mixed with water to activate …