biochemical compound classification

introduction to biochemical compounds

Glucose is an example of a biochemical compound. The prefix bio- comes from the Greek word that means life. A biochemical compound is any carbon-based compound that is found in living things. Biochemical compounds make up the cells and tissues of living things. They are also involved in all life processes, including making and using food for energy. Given their diversity of functions, its not surprising that there are millions of different biochemical compounds. Q: Plants make food in the process of photosynthesis. What biochemical compound is synthesized in photosynthe- sis? A: Glucose is synthesized in photosynthesis. Virtually all living things use glucose for energy, but glucose is just one of many examples of biochemical compounds that are found in most or all living things. In fact the similarity in biochemical compounds between living things provides some of the best evidence for the evolution of species from common ancestors. A classic example is the biochemical compound called cytochrome c. It is found in all living organisms because it performs essential life functions. Only slight variations in the molecule exist between closely related species, as you can see in the Figure and the single-celled tetrahymena (pictured in the Figure 1.1), the cytochrome c molecule is nearly 50 percent the same.

textbook_image

structure of biochemical molecules

All biochemical molecules contain hydrogen and oxygen as well as carbon. They may also contain nitrogen, phosphorus, and/or sulfur. Almost all biochemical compounds are polymers. Polymers are large molecules that consist of many smaller, repeating molecules, called monomers. Glucose is a monomer of biochemical compounds called starches. In starches and all other biochemical polymers, monomers are joined together by covalent bonds, in which atoms share pairs of valence electrons. Click image to the left or use the URL below. URL:

size of biochemical molecules

Most biochemical molecules are macromolecules. The prefix macro- means large, and many biochemical molecules are very large indeed. They may contain thousands of monomer molecules. The largest known biochemical molecule is called titin. It plays an important role in muscle contraction. The human form of the molecule contains more than 34,000 monomers. Its chemical formula is C169723 H270464 N45688 O52243 S912 . Its chemical name contains almost 190,000 letters, and it has been called the longest word in any language.

classes of biochemical compounds

Although there are millions of biochemical compounds, all of them can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in the Table 1.1. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins Q: In which class of biochemical compounds would you place glucose? A: Glucose is a sugar in the class carbohydrates. Like other carbohydrates, it contains only carbon, hydrogen, and oxygen. It provides energy to the cells of living things. Q: Look back at the chemical formula for titin. In which class of biochemical compounds should it be placed? A: Titin is a protein. You can tell because it contains sulfur, and proteins are the only biochemical compounds that contain this element.

instructional diagrams

No diagram descriptions associated with this lesson

questions

there are only about 100 different biochemical compounds.

a. true

-->  b. false

the similarity in biochemical compounds between living things provides some of the best evidence for evolution.

-->  a. true

b. false

functions of carbohydrates include

a) storing energy in plants.

b) storing energy in animals.

c) making up cell walls in plants.

-->  d) two of the above

functions of nucleic acids include

-->  a) storing genetic information in cells.

b) speeding up biochemical reactions.

c) regulating life processes.

d) all of the above

elements found in proteins but not in other biochemical compounds include

-->  a) sulfur.

b) nitrogen.

c) phosphorus.

d) two of the above

almost all biochemical compounds are polymers.

-->  a. true

b. false

diagram questions

No diagram questions associated with this lesson