Rainier Moreno-Lacalle’s Reviews > Molecular Biology of the Gene > Status Update

A cancer cell is a cell that has lost the ability to control its growth and division. It divides both when and where it should not, and tumors are the result of its disorganized growth within an animal host. There exists two main hypotheses for the origin of cancer cells; both are essentially genetic.
1. Somatic mutations
2. Insertion of new genetic material

Work on, say arteriosclerosis or mental retardation may convey a social responsibility, but we must always ask whether such socially motivated commitments are the outgrowth of serious science or whether, at best, they represent the sloppy aspirations of well intentioned amateurs.

Burn!

Control over cell metabolism is also quickly effected by end-product inhibition of enzyme function. An end-product metabolite can reversibly combine with the first enzyme involved in its specific biosynthetic pathway.

Control over cell metabolism is also quickly effected by end-product inhibition of enzyme function. An end-product metabolite can reversibly combine with the first enzyme involved in its specific biosynthetic pathway.

The most direct way to study the genetic code is to examine protein synthesis in cell-free extracts. The most useful in vitro systems employ cell extracts that have been depleted of their original messenger component.

DNA molecules are not the direct templates for protein synthesis. The genetic information of DNA is first transferred to RNA molecules. In turn, RNA molecules act as the primary templates that order amino acid sequences in proteins...

... the double helix tells us that all nucleotides are geometrically equivalent, unambiguously revealing that the genetic codes resides in their linear sequences.

Chromosomes control the hereditary properties of all cells and are linear collections of specific factors called genes. Each gene can affect the character of a cell in a highly specific way. This is shown by the striking cellular effects of hereditary changes in gene structure (mutations)... it is possible to increase mutation rates by applying specific chemicals or radiation (mutagens).

The growth and division of cells are based upon the same laws of chemistry that control the behavior of molecules outside of cells. Cells contain no atoms unique to the living state; they can synthesize no molecules which the chemist, with inspired, hard work, cannot some day make. Thus there is no special chemistry of living cells.