What is the name of the molecule that living things use for energy? Bellringer What is the name of the molecule that living things use for energy?

UNIT 2 PART 3: CELLULAR RESPIRATION Energy is the ability to do work. All living things need energy, and they get it from food. Carbs are the main source. Some energy is released as heat to maintain body temp. The rest is stored in chemical form. The reaction takes place in many small steps so energy is not lost.

Energy for Cell Work E ATP E Energy from food This energy releasing process is called CELLULAR RESPIRATION. As the chemical bonds in food are broken, energy is released. The energy released is used to change ADP into ATP. Energy for Cell Work E ADP + P ATP E Energy from food

ATP – the energy molecule ~ ~ High energy bonds where energy is stored ADP has only 2 phosphate groups. During cellular respiration the energy released by the breakdown of food is used to attach another P group to ADP making it ATP.

When the last P is removed from ATP, the energy is transferred to another molecule to do work like cell growth, repair, or transport.

Cellular respiration uses the simplest form of carbs obtained from digestion - glucose One molecule of glucose (C6H12O6,), an organic molecule, can make 38 ATP molecules (energy storage in the cell) Cellular respiration can be written as: C6H12O6 + 6O2  6CO2 + 6H2O + ENERGY (ATP)

There are two types of respiration Anaerobic Does not use oxygen Food is not broken down completely Little energy is released (4 ATPs) Alcohol or lactic acid are wastes (Fermentation) Occurs in cytoplasm Aerobic Uses oxygen Food is broken down completely A lot of energy is released (38 ATPs) Carbon dioxide and water are wastes Occurs in mitochondria

OVERVIEW OF CELLULAR RESPIRATION ANAEROBIC RESPIRATION Alcoholic fermentation (yeast) 2 ethyl alcohol + 2 CO2 cytoplasm Net total: 2 ATP 2 ATPs 4 ATPs Lactic acid fermentation (bacteria) 2 Lactic acid 2 pyruvic acid glucose glycolysis Acetyl CoA mitochondrion 6 CO2 + 6 H2O + 34 ATP AEROBIC RESPIRATION Electron Krebs cycle Transport Net total: 36 ATP Chain C6H12O6 + 6O2  6CO2 + 6H2O + 36 ATP

MUSCLE FATIGUE Muscle cells use aerobic respiration. During prolonged periods of exercise muscles sometimes don’t get enough oxygen so they use anaerobic respiration. This produces lactic acid which can build up in the muscles making them sore. Need to rest to recover.

Anaerobic Respiration Aerobic Respiration in cytoplasm in mitochondria 2 ATP 2 ____ E Word Bank: Pyruvic acid, H2O, CO2, CO2, Lactic Acid, Alcohol, ATP, ATP, ADP, Glucose, O2 1 _______ 4 ADP 4 ____ 34 ADP 34 ____ E E 6 ________ & 6 ________ 2 ______ _____ Yeast Bacteria 2 ________ & 2 __________ 2 _______ _______