As we mentioned in the last article on proteins and amino acids, the shape of a protein is very important to its function. To understand how a protein gets its final shape or conformation, we …

These sequences, often found close to the N- or C-terminus, can be thought of as the protein’s “train ticket” to its final destination. For more about how this works, see the article on protein …

How do we go from the amino acid sequence of a polypeptide to the three-dimensional structure of a mature, functional protein? To learn how interactions between amino acids cause a …

Thus, during expression of a protein-coding gene, information flows from DNA → RNA → protein. This directional flow of information is known as the central dogma of molecular biology.

In the diagram below, mRNAs are being transcribed from several different genes. Although transcription is still in progress, ribosomes have attached each mRNA and begun to translate it …

The operator is a negative regulatory site bound by the lac repressor protein. The operator overlaps with the promoter, and when the lac repressor is bound, RNA polymerase cannot …

Passage through a channel protein allows polar and charged compounds to avoid the hydrophobic core of the plasma membrane, which would otherwise slow or block their entry …

The formation of a functional protein from amino acids occurs in several stages, referred to as primary, secondary, tertiary, and quaternary structures. Each stage represents a progressively …

As a protein is made, it passes step by step through a shipping "decision tree." At each stage, the protein is checked for molecular tags to see if it needs to be re-routed to a different pathway or …

A transmembrane protein goes across the cell membrane, from the cytoplasm to the outside of the cell.