The La Brea Tar Pits in Los Angeles are the site of millions of fossils from the ice age. Woolly mammoths, giant sloths, dragonflies, and other plants and animals from this era have been found in these pits. Scientists at the tar pits discovered that many of the smaller animals they extracted from the pits still exist around Los Angeles today. But many of the larger mammals—such as woolly mammoths and saber-toothed tigers—are now extinct. Why do you think this is the case? What can scientists learn about Los Angeles’ climate history by studying the specimens found in these tar pits?

both anaerobic and aerobic respiration use glucose (or other carbohydrates), proteins and lipids to produce atp and nadh. cell uses those energy molecules, obtained from food and   breaks them down during the chemical reactions of respiration. in anaerobic respiration, nadh is regenerated to nad+ by enzymes lactate dehydrogenase (lactate is produced, e.g. in muscle cells) or by alcohol dehydrogenase where ethanol is produced (alcohol fermentation), while in aerobic respiration, electrons from nadh are deposited in the mitochondria to regenerate nad+ (electron transport chain. anaerobic respiration produces 2 atp per molecule of glucose compared to aerobic respiration where about 38 atp molecules are produced.