My tutoree is now in 8th grade, and, miraculously, didn't carry home another Prentice Hall "science" book. But he just got a smearox of three pages which smell familiar. Remember "The weak force is the key to the power of the Sun."? "Because of the air within it, a huge ocean liner can float on the surface of the ocean."? The ridiculous eclipse drawing that showed both limbs of Sun, moon, and Earth lying on just two straight lines? Now they're "doing" biology. Not, as Einstein prescribed, as simply as possible. Way simpler than that. Summary: the brighter and more curious the student, the more discouraged and confused this crap will leave him. Anyone getting an A on this material is a parrot who has been misled to believe s/he has learned something. I'll indent their text. P 88. 4-2 Respiration: Using the Energy in Food Green plants (autotrophs) I'm glad they cleared that up. I thought they meant photoautotrophs. make their own food. Animals (heterotrophs) eat green plants or other animals that eat green plants. Let's see, so fish eat mosquito larvae and mosquitos eat green plants. Carnivores have an agreement not to eat each other. You have learned that energy is stored in the bonds that link together atoms in foods, such as glucose. That comma makes the sentence wrong. You can think of the energy stored in food as a savings account. You eat food to add to your energy savings account. Huh?? You eat food to add to the energy stored in food? P89 During aerobic respiration, food enters the mitochondria. Burgers, fries, Ding-Dongs with taco sauce, oysters with Cool Whip, ... The food is broken down when it combines with oxygen. During this process, water and carbon dioxide are produced as waste products. Yeah, that water stuff is pretty useless. A worse greenhouse gas than CO2. But respiration produces BOTH! We must save the Earth by banning respiration. And club soda. Maybe if we could consume enough anti-oxidants ... The energy released from food during respiration is not always used right away by the cell. Often, it is stored in a chemical compound called ATP. But sometimes the cell just needs a hit of warm club soda? Basically, ATP is a chemical substance that can be used to store energy. How does a chemical store energy without becoming some other chemical? When a cell needs energy, it breaks down the ATP and uses the energy released. Is this like breaking down food? Although respiration occurs in a series of complex steps, the overall process can be written down as a word equation and as a chemical equation, as follows: Glucose + Oxygen --> Carbon Dioxide + Water + ATP (energy) or C6H12O6 + 6O2 --> 6CO2 + 6H2O + ATP Gee, I thought the P in ATP had something to due with phosphorus. But there's no phosphorous on the left side. Wow, cells can make phosphorus out of glucose. Nuclear transmutation! Notice anything familiar about the equation for respiration? You are quite right if you said it is the opposite of the equation for photosynthesis. Yeah except there's no chlorophyll in respiration and you didn't mention ATP in photosynthesis. Maybe that's what you mean by "opposite". p90 So how do anaerobic organisms get their energy? The answer is that anaerobic organisms undergo a different type of respiration, appropriately called anaerobic respiration. I'm sure glad you told me it was appropriately. Scientists use the term fermentation when they speak of anaerobic respiration. Do they mean the same thing, or does one occur during the other, or is one an example of the other, or are they just wishing they had a beer? Carbon dioxide is also the source of bubbles in alcoholic beverages such as beer and wine. But not soda? Hey, my dad's Chianti doesn't bubble. Must be some new kind of emissions control. 4-2 Section Review 2. Why are the mitochondria appropriately called the powerhouses of the cell? Beats the hell out of me, but I'm sure glad you told me it was appropriately.