Explore and review the biological molecules necessary for life.

Online biology textbook discussing the chemical nature of water, and the importance of its molecular structure to life. Also discusses at length the organic molecules nucleic acids, proteins, lipids, and carbohydrates.

In this online biology textbook, learn about atoms and molecules as they relate to life. Find out about topics such as electrons and energy, chemical bonding, and chemical reactions.

This simulation can be used to study molecule movement across a semipermeable membrane.

On this site, students learn about DNA and genes in the science of biology including the deoxyribonucleic acid molecule, nucleotides, codons, and interesting facts.

Very good description of the process of translation with a good graphic to go along with it. Includes a chart classifying all of the RNA Codons.

This resource is an article about the cell membrane, and its role in water and solute movement in and out of the cell.

Find out about the process of transcription, where the DNA sequence of a gene is transcribed to make an RNA molecule.

Discover new knowledge about molecular biology- how molecules fit together as a lock and key. This has given researchers new diagnostic tools that use immune cells from mice to produce antibodies to detect a specific virus or bacterium.

Discusses the properties of enzymes and the concept of enzyme-substrate specificity, and how a substrate molecule binds to an enzyme to form an enzyme-substrate complex. An overview of enzyme-substrate reactions is also presented.

Students will be able to identify two ways that molecules and ions cross the plasma membrane.

A stop codon is a nucleotide triplet in messenger RNA that signals the end of a protein during the translation process. Read about how this works, the different types of stop codons, and how a mutation can sometimes occur.

A start codon is a nucleotide triplet in a genetic sequence that occurs at the start of a protein's synthesis. Read about how this works and how a mutation can sometimes occur.