Lecture-5B-Proteins-_42855 - ProteinBiomolecules Enzymes:...

Info icon This preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
Protein Biomolecules • Proteins perform most all functions in an organism: – Enzymes: catalyze chemical reactions – Structural & movement functions – Transport & Regulatory functions – Extracellular: hormones, antibodies, digestive functions Carboxyl group • Proteins are polymers of amino acids: all Central, b amino acids have the same structural plan (d tt d li ) i α =carbon (dotted line) in common; but each possess 1 of 20 R unique side chains, or R groups . Amino group
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
• Differences in the amino acid side groups give them their individual properties: P l h d ti h ( idi ) iti h (b i ) – Polar, charged: negative charge (acidic) or positive charge (basic) – Polar, uncharged; and Nonpolar – Adjacent cystiene sulfhydryl groups ( SH) Adjacent sulfhydryl groups ( SH) form a disulfide bridge: S S Proline : has a unique ring structure α‐ carbon • Dehydration reactions link amino acids monomers together; result in formation of a peptide bond : H 2 O
Image of page 2
• Proteins are comprised of one or more polypeptide chains. – Polypeptide = few to a 1000 amino acids in length – Each protein: possesses a unique sequence of amino acids … that precisely forms into a unique 3 D shape *Important, because …that precisely forms into a unique 3 D shape the structure determines how it functions most proteins depend on the ability to recognize & bind other molecules. • Protein structure of lysozyme (an enzyme) Coiling & folding of Globular shape: polypeptide chain. Groove: binding occurs here
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Proteins have Four Levels of Structure: Primary, Secondary, Tertiary, & Quarternary 1. Primary Structure: the sequence & types of amino acids comprising a polypeptide chain • This underlies and determines the higher levels of structure Ala Lys Polypeptide chain Peptide linkages *The information dictating the primary structure of all proteins is stored in DNA (in the form of genes).
Image of page 4
H bond formation between amino groups & carbonyl Secondary Structure groups of the polypeptide backbone produced by twists & turns of the amino acid chain.
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern