Table of Contents
What happens to the protein if a part of it is incorrect?
Proteins that fold improperly may also impact the health of the cell regardless of the function of the protein. When proteins fail to fold into their functional state, the resulting misfolded proteins can be contorted into shapes that are unfavorable to the crowded cellular environment.
What remains the secondary structure of a protein?
Secondary structure refers to regular, recurring arrangements in space of adjacent amino acid residues in a polypeptide chain. It is maintained by hydrogen bonds between amide hydrogens and carbonyl oxygens of the peptide backbone. The major secondary structures are α-helices and β-structures.
Why might a protein have two separate binding sites?
Many weak bonds are needed to enable a protein to bind tightly to a second molecule, which is called a ligand for the protein. Separate regions of the protein surface generally provide binding sites for different ligands, allowing the protein’s activity to be regulated, as we shall see later.
What happens to proteins as they pass through the Golgi apparatus?
What happens to proteins as they pass through the Golgi apparatus? Proteins are modified by having sugars attached or removed. Within the Golgi apparatus, different proteins are modified by the activities of sugar molecules. After modification, the proteins move within vesicles to specific locations in the cell.
Why do proteins form secondary structures?
Hydrogen bonding between amino groups and carboxyl groups in neighboring regions of the protein chain sometimes causes certain patterns of folding to occur. Known as alpha helices and beta sheets, these stable folding patterns make up the secondary structure of a protein.
What causes change in protein structure?
Proteins change their shape when exposed to different pH or temperatures. The body strictly regulates pH and temperature to prevent proteins such as enzymes from denaturing. Some proteins can refold after denaturation while others cannot.
Can a protein have more than one binding site?
Many ligand-binding proteins possess multiple binding sites for the same ligand, having binding stoichiometries higher than 1:1. A protein possessing multiple ligand-binding sites may be made up of non-identical subunits, or the binding sites may be non-equivalent if they reside on the same polypeptide chain.
How do proteins bind to receptors?
Receptors are a special class of proteins that function by binding a specific ligand molecule. When a ligand binds to its receptor, the receptor can change conformation, transmitting a signal into the cell. In some cases the receptors will remain on the surface of the cell and the ligand will eventually diffuse away.
How do proteins travel from one cisterna to the next in the Golgi apparatus?
The proteins travel through the cisternae in sequence in two ways: (1) by means of transport vesicles that bud from one cisterna and fuse with the next, and (2) by a maturation process in which the Golgi cisternae themselves migrate through the Golgi stack.