Overview of metabolic pathways, energy flow in a cell, and anabolism and catabolism. Metabolism is the sum total of all the chemical reactions occuring in the body Now cata and ana bolism are just Is metabolism in animals catabolism or anabolism? What is the relationship between carbohydrate metabolism and cancer?. Describe the relationship between metabolism, Catabolism, and anabolism. List three basic catabolic pathways and the estimated ATP yield for each.
They can also provide a food source for animals that eat the plant, like the squirrel below. In both cases, the glucose will be broken down through cellular respiration, generating ATP to keep cells running.
Anabolic and catabolic pathways The processes of making and breaking down glucose molecules are both examples of metabolic pathways. A metabolic pathway is a series of connected chemical reactions that feed one another. The pathway takes in one or more starting molecules and, through a series of intermediates, converts them into products.
Metabolic pathways can be broadly divided into two categories based on their effects. Photosynthesis, which builds sugars out of smaller molecules, is a "building up," or anabolic, pathway. In contrast, cellular respiration breaks sugar down into smaller molecules and is a "breaking down," or catabolic, pathway.
Energy is typically required. Energy is typically released. Anabolic pathways build complex molecules from simpler ones and typically need an input of energy. Building glucose from carbon dioxide is one example.
Metabolism and energy
Other examples include the synthesis of proteins from amino acids, or of DNA strands from nucleic acid building blocks nucleotides. When molecules collide there is the possibility of a reaction taking place, but only if the colliding molecules: This is called collision theory. The more molecules present, the faster the reaction. Therefore reactions take place faster in concentrated solutions than in solutions that are more dilute.
Overview of metabolism
At high temperatures molecules have more energy than at lower temperatures. Therefore collisions are more frequent and the likelihood of the molecules having enough energy is greater.
Consequently the rate of chemical reactions increases with increasing temperature. Activated complexes and activation energy Some reactions take place in a single step. We can represent this using an energy profile. An activated complex or transition state forms between reactant and product.
This is not a 'real' substance in the sense that it can be isolated and put in a test tube. But based on various pieces of experimental evidence it is the chemist's model of how the reaction occurs. The energy 'hump' shows how much energy reacting molecules must have for a 'successful' collision, i.
The formation of an activated complex requires energy to bring molecules together in the correct orientation. Therefore, it is always an endergonic reaction.
The energy required is called the activation energy Ea.
After each step a reaction intermediate forms. Unlike an activated complex this has a real existence. For each step an activated complex is formed and there is an associated activation energy. The step with the highest activation energy is the rate-determining step in the reaction and controls how fast the overall reaction is.
Catalysts In chemical factories high temperatures and pressures are often used.
Overview of metabolism (article) | Khan Academy
However, this energy costs money. Catalysts make chemical reactions go more quickly and their use in the chemical industry saves time and money. Cells are extremely sensitive to temperature and pressure. Catalysts are essential to make sure metabolic reactions take place under conditions the cell can withstand.
Enzymes are nature's catalysts.