Proteins

• We all have things that challenge us- and for me- it is folding. Sheets, towels, shirts- let's just say I invest in a lot of anti-wrinkle laundry spray. Amazing invention. My issue with folding extends to paper too.
• Folding in the classroom can be a powerful way to organize concepts, but for me, it was the actual folding part that I tended to get stuck on.
• Folding


  A way to take something and make it more organized or condensed so it doesn't have to take up as much space
• In biology, folding can also have a lot to do with function.
• Proteins can play so many roles. They can make up channels, be a part of structure, serve as enzymes for important biological processes, be involved with protecting the body...just to name a few.
• Producing a long chain of amino acids doesn't necessarily equal a functional protein. There are modifications to a protein that often need to happen in order for it to be functional.
• Modifications


  Adding certain chemical groups, such as phosphorylation
• Folding


  Another important event to make a functional protein
• Shape and function, in biology, frequently go hand in hand.
• Protein receptors and the signal molecules that bind them can fit together so perfectly to start some type of cellular response.
• Enzymes, which are frequently proteins, have a very specific shape for the substrates that they build up or break down.
• Primary structure


  The sequence of amino acids that make up a protein
• Amino acids are the monomer---which means the building block---of a protein. They are held together by peptide bonds.
• In protein synthesis, amino acids are added to form a polypeptide chain and proteins are made of 1 or more of these polypeptide chains.
• Genes, which are made of DNA, determine the order and number of these amino acids. That sequence is critical to the protein's structure and function.
• Even a single change of an amino acid has the potential to affect a protein's function.
• R group


  Also called a side chain
• Secondary structure


  Folding that occurs in the sequence of amino acids, such as alpha helix and beta pleated sheet
• The folding in secondary structure is largely due to hydrogen bonds involving the backbone of the amino acid structure.
• Tertiary structure


  The 3D shape of a functional protein, influenced by interactions involving the R groups
• Hydrophilic R groups may hang out on the outside of the protein, while hydrophobic R groups may hang out in the inside part of the protein.
• Ionic bonds, Van der Waals interactions, disulfide bonds, and hydrogen bonds involving the R groups also influence the folding in tertiary structure.
• Quaternary structure


  A protein consisting of more than 1 polypeptide chain, where the interactions between the subunits keep them together
• Proteins often have help in the folding process, such as chaperonins, which can provide an environment ideal for the proteins' folding.
• All the interactions in primary, secondary, tertiary, and quaternary structure are paramount for a mature protein to have its correct shape so it can carry out its function.
• There are many diseases that are related to protein misfoldings.
• Each protein has an ideal environment for functioning, which might include a certain temperature or pH range. If the protein is exposed to something outside of its ideal environment, it can disrupt the interactions that take place at the different structural levels, denature the protein, and prevent it from functioning correctly.