Orders of protein structure: primary, secondary, tertiary, and quaternary. Alpha helix and beta pleated sheet.

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, …

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 …

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 …

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 …

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

The process of protein synthesis begins in the nucleus with DNA, which encodes the genetic instructions for making proteins. These instructions are used to build intermediate molecules …

Proteins in the extracellular matrix, like the fibronectin molecules shown in green in the diagram above, can act as bridges between integrins and other extracellular matrix proteins such as …

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 …

As these ribosomes make proteins, they feed the newly forming protein chains into the lumen. Some are transferred fully into the ER and float inside, while others are anchored in the …