The work of the cell is carried out by the many different types of molecules it assembles, mostly proteins. Protein molecules are long, usually folded chains made from 20 different kinds of amino acid molecules. The function of each protein molecule depends on its specific sequence of amino acids and its shape. The shape of the chain is a consequence of attractions between its parts.
Learning Goal 4a
The genetic information encoded in DNA molecules provides instructions for assembling protein molecules.
Learning Goal 4b
The genetic information encoded in DNA molecules is virtually the same for all life forms.
Learning Goal 4c
Before a cell divides, the instructions are duplicated so that each of the two new cells gets all the necessary information for carrying on.
Learning Goal 5
Complex interactions among the different kinds of molecules in the cell cause distinct cycles of activities, such as growth and division. Cell behavior can also be affected by molecules from other parts of the organism or even other organisms.
Learning Goal 6
Gene mutation in a cell can result in uncontrolled division called cancer. Exposure of cells to certain chemicals and radiation increases mutations and thus the chance of cancer.
Learning Goal 9
Some protein molecules assist in replicating genetic information, repairing cell structures, helping other molecules get in or out of the cell, and generally catalyzing and regulating molecular interactions.