Chapter 4 Carbon and the Molecular
Diversity of Life Lecture Outline
Overview: Carbon – The Backbone of Biological Molecules
· Although cells are 70–95% water, the rest consists mostly of carbon-based compounds.
· Carbon is unparalleled in its ability to form large, complex, and diverse molecules.
· Carbon accounts for the diversity of biological molecules and has made possible the great
diversity of living things.
· Proteins, DNA, carbohydrates, and other molecules that distinguish living matter from
inorganic material are all composed of carbon atoms bonded to each other and to atoms of other
· These other elements commonly include hydrogen (H), oxygen (O), nitrogen (N), sulfur
(S), and phosphorus (P).
Concept 4.1 Organic chemistry is the study of carbon compounds
· The study of carbon compounds,
deals with any compound with
carbon (organic compounds).
· Organic compounds can range from simple molecules, such as CO
, to complex
molecules such as proteins, which may weigh more than 100,000 daltons.
· The overall percentages of the major elements of life (C, H, O, N, S, and P) are quite
uniform from one organism to another.
· However, because of carbon’s versatility, these few elements can be combined to build an
inexhaustible variety of organic molecules.
· Variations in organic molecules can distinguish even between individuals of a single
· The science of organic chemistry began in attempts to purify and improve the yield of
products obtained from other organisms.