MonosaccharidesĪ monosaccharide is a monomer of carbohydrates. Polysaccharides are the polymers, and can consist of hundreds to thousands of monomers. Disaccharides (di- = “two”) are made up of two monomers. Monosaccharides are the monomers of carbohydrates. In fact, the chemical formula for a “generic” molecule of carbohydrate is (CH 2O) n.Ĭarbohydrates are referred to as saccharides, a word meaning “sugars.” Three forms are important in the body. A carbohydrate is a molecule composed of carbon, hydrogen, and oxygen in most carbohydrates, hydrogen and oxygen are found in the same two-to-one relative proportions they have in water. The term carbohydrate means “hydrated carbon.” Recall that the root hydro- indicates water. The bonds between their monomers are broken, via the donation of a molecule of water, which contributes a hydrogen atom to one monomer and a hydroxyl group to the other. Polymers are split into monomers by hydrolysis (-lysis = “rupture”). Each monomer contributes: One gives up a hydrogen atom and the other gives up a hydroxyl group. As was noted earlier, this reaction results in the release of a molecule of water. Monomers form polymers by engaging in dehydration synthesis (see Figure 2.14). There are many examples of monomers and polymers among the organic compounds. Like beads in a long necklace, these monomers link by covalent bonds to form long polymers (poly- = “many”). However, some macromolecules are made up of several “copies” of single units called monomer (mono- = “one” -mer = “part”). Any large molecule is referred to as macromolecule (macro- = “large”), and the organic compounds in this section all fit this description. Five functional groups are important in human physiology these are the hydroxyl, carboxyl, amino, methyl and phosphate groups ( Table 2.1).Ĭarbon’s affinity for covalent bonding means that many distinct and relatively stable organic molecules nevertheless readily form larger, more complex molecules. You can think of functional groups as tightly knit “cliques” whose members are unlikely to be parted. A functional group is a group of atoms linked by strong covalent bonds and tending to function in chemical reactions as a single unit. Moreover, the atoms to which carbon atoms bond may also be part of a functional group. Many combinations are possible to fill carbon’s four “vacancies.” Carbon may share electrons with oxygen or nitrogen or other atoms in a particular region of an organic compound. If you study the figures of organic compounds in the remainder of this chapter, you will see several with chains of hydrocarbons in one region of the compound. Carbon and hydrogen groupings are called hydrocarbons. Rather, carbon atoms tend to share electrons with a variety of other elements, one of which is always hydrogen. When they do share, however, they do not share all their electrons exclusively with each other. Instead, they readily share electrons via covalent bonds.Ĭommonly, carbon atoms share with other carbon atoms, often forming a long carbon chain referred to as a carbon skeleton. Carbon atoms do not complete their valence shells by donating or accepting four electrons. Recall that carbon atoms have four electrons in their valence shell, and that the octet rule dictates that atoms tend to react in such a way as to complete their valence shell with eight electrons. What makes organic compounds ubiquitous is the chemistry of their carbon core. Before exploring these compounds, you need to first understand the chemistry of carbon. The four types most important to human structure and function are carbohydrates, lipids, proteins, and nucleic acids. They are found throughout the world, in soils and seas, commercial products, and every cell of the human body. Organic compounds typically consist of groups of carbon atoms covalently bonded to hydrogen, usually oxygen, and often other elements as well. Identify the building blocks of nucleic acids, and the roles of DNA, RNA, and ATP in human functioning.Describe the structure of proteins, and discuss their importance to human functioning.Discuss four types of lipids important in human functioning.Provide examples of three types of carbohydrates, and identify the primary functions of carbohydrates in the body.Explain the chemistry behind carbon’s affinity for covalently bonding in organic compounds.Identify four types of organic molecules essential to human functioning.By the end of this section, you will be able to:
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |