Carl is a very happy and busy carbon atom. He is a very small creature. In fact, he is so small that you cannot see him with just your plain eyes. You must use a special type of microscope to even get an idea what he looks like. He can be found almost everywhere. He likes to join together with a few of his friends like other carbon, oxygen, hydrogen, and nitrogen atoms to form many of the compounds found in living things. When Carl is part of a compound it is called an organic compound and the most important groups of organic compounds found in living things are carbohydrates, lipids, nucleic acids, and proteins. Many of these compounds are found in the foods we eat and they provide energy for the body. Carl is even found in fossil fuels such as gas, gasoline, oil, and coaltlmt are derived from the remains of long-dead organisms.
One day Carl and some of his human friends were getting ready to participate in a 10 mile marathon. It was a chilly Saturday morning in March and the friends were stretching, warming up their muscles, and trying to keep warm.
Suddenly, one human began to feel like he was going to faint! As his friends gathered around him, they learned that he was in such a hurry to get to the marathon starting site that he didn't bother to eat breakfast. Carl said flatly, "Real dumb, real dumb." But then quickly interrupted, "We need to get him some energy, he's trying to run this race on empty! Everybody, search your backpacks for food!" 1
^fe ' "%. ^
They quickly came up with some fruit, a beef sausage patty on an English muffin and some water. The weary runner thanked Carl for taking the initiative to come to his aid and Carl responded, "Thank the Sun." k. 1
, "What?" they all asked. And as usual, Carl took the opportunity to explain to them how important he is in this whole scheme of things. He explained that the fainting runner should thank the sun because humans would never be able to have sausages, fruit, bread and water for breakfast if it were not for the rays of energy from the sun and other natural resources.
Carl further explained that plants can't just turn on the stove and cook something or look into the refrigerator for food. Plants use energy to make food. They use a process called photosynthesis to make their own food by using light energy from the sun. The main steps for the process of plants making their own food (photosynthesis) are (1) Chlorophyll in the chloroplasts of plant cells absorbs light from the sun, (2) energy from the sun separates the water molecules (3), hydrogen joins with carbon dioxide to make sugar (food) and (4) the sugar is carried to other parts of the plant with the extra oxygen being released into the air.
After step one above, the cell needs water and carbon dioxide to make sugar. As plant roots absorb water from the soil, the water moves up the through the stem of the plant to the leaves. Carbon dioxide, a gas in the air, enters the plant through small openings called stomata (stoma, singular) found on the underside of the leaves. The water and carbon dioxide move into the chloroplasts once they get inside the leaves. Everyone knows that food provides energy for the body but Carl explained to the group how food provides energy. When you eat food your body does not get energy from it immediately. First, the food passes through the digestive system where the carbohydrates in the food are converted into glucose, a sugar. When cells need energy they get it through a process called respiration where the cells break down simple food molecules such as glucose and release the energy from the glucose molecules.
Cells continuously store and use energy as needed. During photosynthesis, plants capture the sun's energy and store it in the form of carbohydrates, including sugars and starches. During cellular respiration, chemical reactions break down carbohydrates releasing energy that cells can use. There are two main phases of respiration: (1) Glycolysis which takes place in the cytoplasm of the cell and (2) respiration that requires oxygen which takes place in the mitochondria if oxygen is present. If there is no oxygen present the second step of cellular respiration is called fermentation. ^^^JBBfcj^^^, KB '-; KBHH
Carl was pleased that his fainted friend had arrived early enough to eat and have enough time for the energy from the food to begin kicking in before the start of the marathon. He also let his friends know who important he is as a carbon atom. "The carbon atom is the backbone of the carbohydrate compounds." said Carl. "And the processes of photosynthesis and respiration keep the oxygen and carbon dioxide levels pretty balanced in our atmosphere.
\ ' Carl also reminded his friends that the quantity and quality of natural resources such as oil, petroleum, clean water and air, soil, plants and animals are all in danger of decreasing. He really is trying to remind us that all of us have a big role in protecting and conserving our natural resources so that the processes of photosynthesis and respiration can s continue, balanced and uninterrupted. Depleting natural resources is [terrible thing to do. We want to make sure we will have enough energy to keep us from "running on empty.'