PPT-Proteins 2.4.1 Amino acids are linked together by condensation to form polypeptides

Polypeptides are chains of amino acids linked together by condensation reactions the main or only component in proteins Some proteins are composed of only one polypeptide chain while others are made of 2 or more. Amino Acids . of Medical Importance. Amino acids. Amino Acids are the . building blocks . of . proteins. ONLY . 20 amino acids . (out of 300 in nature) are present in . human body . (that are coded for by . The 411. Proteins account for more than 50% of the dry mass of most cells. Protein functions include structural support, storage, transport, cellular communications, movement, and defense against foreign substances. Essential idea: Proteins have a very wide range of functions in living organisms.. One of the central ideas in Biology is that structure dictates function. Above you can see insulin in its secondary, tertiary and quaternary structures. Polypeptides vary hugely in the combination and number of amino acids that they are composed from. Even if we consider a single polypeptide it's properties, and hence it's function, would vary greatly depending on it's level of structure. Insulin can exist in all these forms, but the active form, which controls blood glucose levels, is a the tertiary structure.. Codons. Prefixes, Suffixes and Vocabulary. Poly. = many. Peptide bond . =bond between two amino acids.. Anti. = against, opposite. Dehydration. = loss of water. Polypeptide. = long assembled string of amino acids.. 2. : Molecular Biology. 2.4 Proteins. Learning objectives. U: amino acids are linked together by condensation to form polypeptides. U: There . are 20 different amino acids in polypeptides synthesized on ribosomes.. https://www.youtube.com/watch?v=hpaki7F4HR0. http. ://www.wisc-online.com/objects/index_tj.asp?objID=AP13304. Cells contain thousands of different proteins, each performing a specific task.. Examples: Enzymes, . B.2. Properties of 2-amino acids . (B.2.2). Zwitterion. (dipolar) . amino acids contain both acidic and basic groups in the same molecule . therefore, are . amphoteric. in nature (capable of behaving as acids or bases). Proteins account for more than 50% of the dry mass of most cells. Protein functions include structural support, storage, transport, cellular communications, movement, and defense against foreign substances. Unit objectives:. Identify amino acid classifications based on nutritional use and chemical properties of side chains. Describe the primary, secondary, tertiary and quaternary structures of proteins. 2.4 Proteins. IB Biology SFP - Mark . Polko. 2. IB Biology SFP - Mark Polko. Understandings. :. Nature. . of science. 3. IB Biology SFP - Mark Polko. Applications. and . skills. Essential idea:.  Proteins have a very wide range of functions in living organisms. 6. 6.1 Differentiate . between essential amino acids and nonessential amino acids.. 6.2 List . the functions of protein in the body.. 6.3 List . the steps for protein digestion and absorption in the body. . Each amino acid (aa) shares a common structure; i.e. an amine (NH. 2. ) group, an acid group (COOH), and a central carbon atom bonded to hydrogen and to a side chain (R).. The side chains qualify aas as acidic, basic, neutral, aromatic, and sulphur-containing amino acids.. Peptide bond formation. : . α-carboxyl group of one amino acid (with side chain R1) forms a covalent peptide bond with α-amino group of another amino acid . ( . with the side chain R2) by removal of a molecule of water. The result is : Dipeptide ( i.e. Two amino acids linked by one peptide bond). By the same way, the dipeptide can then forms a second peptide bond with a third amino acid (with side chain R3) to give . Acids. By . Professor . Dr. Jamal Ahmed Abdel -Barry. . Rare Amino Acids. In addition to 20 standard amino acids there are several amino acids that can be isolated from the hydrolysis of special type of protein, all are derivatives of some standard amino acids..