The Metabolism Resource Page
Metabolism is the group of chemical reactions that take place in the organism to maintain life. Metabolism is normally classified into two divisions: catabolism and anabolism. In catabolism, or destructive metabolism, a larger molecule is broken down to release energy. In anabolism, or constructive metabolism, smaller molecules are converted to larger molecules of protein, carbohydrate, and fat.
In a metabolic reaction, one chemical is changed into another chemical through a series of steps, by enzymes. Enzymes function as catalysts to allow the chemical reactions to proceed effectively. When the metabolism in the body is defective, it can cause metabolic diseases such as hyperthyroidism, hypothyroidism, Type 1 diabetes, and Type 2 diabetes.
- Overview of Metabolism: This page gives an overview of metabolism and the carbon cycle.
- Metabolism: This page gives a basic introduction to metabolism and explains the different categories of metabolism.
- What is Metabolism?: This page provides a good explanation of metabolism, energy, work, and types of metabolism with graphs and diagrams.
Amino Acids and Proteins
Proteins are organic compounds consisting of amino acids linked together by peptide bonds and cross-linked by hydrogen bonds, sulfhydryl bonds, and van der Waals force. Proteins are divided into simple proteins, conjugated proteins, and derived proteins. Amino acids are building blocks of protein and contain a carboxylic acid group, an amine group, and a side bond that differs in every amino acid.
- Proteins and Amino Acids: This page gives introduction to proteins, protein digestion and metabolism, amino acids, and quantitative requirements for amino acids.
- Introduction to Protein and Amino Acids: This page gives good information on protein and amino acids with clear diagrams.
- Chemistry of Amino Acids: This page gives introduction to essential amino acids.
Lipids are natural organic compounds that are composed largely of hydrogen and carbon. The molecule of fatty acid contains phospholipids, fats and oils, waxes, fatty acids, eicosanoids, steroids, and terpenes. The main purposes of lipids are cell membrane development and energy storage. Lipids dissolve in organic solvents such as chloroform and benzene.
- Lipids: This page gives a basic introduction to lipids and their chemical composition.
- Lipids Overview: This page gives detailed information on the chemical composition of lipids with formulas and diagrams.
- About Lipids: This page defines lipids, biological functions, and lipid composition.
Carbohydrates are organic compounds that provide energy to organisms. Carbohydrates take the form of starches, sugars, oligosaccharides, and fibers to supply energy. The main purposes of carbohydrates are the transport of energy, storage, and structural components in organisms. Monosaccharide is the basic unit of carbohydrates and monosaccharides link together to form polysaccharides.
- Carbohydrates: This page gives an introduction to carbohydrates, sugars, and polysaccharides.
- Introduction to Carbohydrates: This page gives an introduction to carbohydrates, the importance of carbohydrates, and body weight regulation.
- Forms of Carbohydrates: This page defines carbohydrates and various forms of carbohydrates.
Nucleotides are monomers and are joined to form phosphate ester bonds. Nucleotides consist of five carbon sugars, phosphate group, and one or two nitrogen rings. Polymers of nucleotides such as RNA and DNA are called nucleic acids. The main purpose of nucleotides is storage and use of genetic information.
- Nucleotides: This page explores nucleotides and their chemical components.
- Nucleotides and Nucleic Acids: This page gives good information on nucleotides, nitrogen bases, nucleic acids, DNA, and RNA.
- Nucleotide Structure: This page clearly explains the structure of a nucleotide.
A non-protein chemical component of enzymes is called a cofactor, and an organic cofactor is called a coenzyme. Coenzymes are small molecules and most are derived from vitamins. Coenzymes are the active part of enzymes and they are loosely bound cofactors. Adenosine triphosphate is a coenzyme used in cells to transport chemical energy.
- Enzymes and Coenzymes: This page gives a basic introduction to enzymes and coenzymes.
- Coenzymes and Cofactors: This page describes coenzymes and cofactors with examples.
- Coenzymes: This page clearly defines coenzymes with chemical structure.
Inorganic component of cofactors are called minerals and these components function as ionic electrolytes. The most important minerals are sodium, calcium, potassium, phosphate, magnesium, and chloride. The main purposes of minerals are maintaining pH and osmotic pressure. These inorganic elements act as cofactors in proteins and are essential for the enzymes activity.
- Minerals: This page clearly explains minerals and the role of minerals in cells and tissues.
Catabolism is the metabolic process in which larger molecules are broken down to produce the energy required by the body. Catabolic reaction changes from organism to organism and different forms of metabolism depend on redox reaction. In redox reactions, the electrons are transferred from donor molecules to acceptor molecules.
- Catabolism: This page gives introduction to catabolic reactions.
- Redox Reactions: This page clearly explains redox reaction with chemical formulas.
- Carbohydrate Catabolism: This page gives introduction to carbohydrate catabolism.
Anabolism is the constructive metabolic reaction in which the energy released from catabolic reactions is used to form complex molecules. Anabolic reactions consist of three stages: production of precursors, changing into reactive forms, and assembling precursors into molecules. Some examples of anabolic reactions are an increase in muscle mass and growth of bone.
- Catabolic and Anabolic Reaction: This page gives a good explanation of catabolic and anabolic reactions with a clear diagram and chemical structure.
- Anabolism: This page clearly explains anabolism, autotrophic nutrition, and heterotrophic nutrition.
- Calvin Cycle: This page gives good introduction to Calvin cycle.
Xenobiotic metabolism is the chemical reaction that changes the xenobiotics chemical structure. This metabolism is normally classified into three stages. In stage I, polar groups are introduced into xenobiotics by enzymes. In stage II, modified compounds are joined to polar compounds. In stage III, the coupled xenobiotics are processed before releasing.
- Xenobiotic Metabolism: This page gives good introduction to xenobiotics.
- Xenobiotics: This page explains various phases in xenobiotic metabolism.
Regulation and Control
Metabolic reactions should be finely regulated to allow organisms to interact actively and to respond to signals in the environment. Metabolic reactions are controlled two ways. First, the enzymes in a metabolic reaction are regulated. Second, the control maintained by the enzymes determines the overall rate of a metabolic reaction. The metabolic regulations are broadly classified into intrinsic regulation and extrinsic regulation.
- Metabolic Control Analysis: This page gives good introduction to metabolic control analysis.
- Cell Signaling: This page contains good information on cell signaling.