Skip to main content

Home/ Chem 109H Fall08/ Group items tagged Protien

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
Becky Kriger

Polypeptides and Proteins - 0 views

student.ccbcmd.edu/...protein.html

Protien polypeptides

shared by Becky Kriger on 08 Dec 08 - Cached
  • A peptide (def) is two or more amino acids joined together by peptide bonds, and a polypeptide (def) is a chain of many amino acids. A protein contains one or more polypeptides. Therefore, proteins (def) are long chains of amino acids held together by peptide bonds.
  • The secondary structure (def) of the protein is due to hydrogen bonds that form between the oxygen atom of one amino acid and the nitrogen atom of another. This gives the protein or polypeptide the two-dimensional form of an alpha-helix or a beta-pleated sheet (see Fig. 4).
  • Amino acids (def) are the building blocks for proteins. All amino acids contain an amino or NH2 group and a carboxyl (acid) or COOH group. There are 20 different amino acids commonly found in proteins
  • ...5 more annotations...
  • To form polypeptides and proteins, amino acids are joined together by peptide bonds (def), in which the amino or NH2 of one amino acid bonds to the carboxyl (acid) or COOH group of another amino acid as shown in (see Fig. 2). Animation showing the formation of a peptide bond.
  • The actual order of the amino acids in the protein is called its primary structure (def) (see Fig. 3) and is determined by DNA.
  • it is commonly said that the order of deoxyribonucleotide bases (def) in a gene determines the amino acid sequence of a particular protein. Since certain amino acids can interact with other amino acids in the same protein, this primary structure ultimately determines the final shape and therefore the chemical and physical properties of the protein.
  • In globular proteins such as enzymes, the long chain of amino acids becomes folded into a three-dimensional functional shape or tertiary structure (def).
  • In some cases, such as with antibody molecules and hemoglobin, several polypeptides may bond together to form a quaternary structure (def) (see Fig 6).
1 - 1 of 1
Showing 20▼ items per page