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 …

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 …

Now, any protein that's made up of a single polypeptide is only going to have primary structure, secondary structure and tertiary structure, but if we're dealing with something like hemoglobin, …

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.

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 protein consists of a unique combination of amino acids drawn from this 20-member library. The amino acids that make up a protein are linked together into long linear chains, like a train …

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 …

To see how cells make proteins, let's divide translation into three stages: initiation (starting off), elongation (adding on to the protein chain), and termination (finishing up).

This diagram shows a G protein-coupled receptor (GPCR), a type of receptor we'll examine in more detail later in the article. GPCRs have seven membrane-spanning domains, as shown by …

The fluid mosaic model of the plasma membrane. Protein, lipid, and carbohydrate components of the membrane.