Download
the structure of proteins n.
Skip this Video
Loading SlideShow in 5 Seconds..
The Structure of Proteins PowerPoint Presentation
Download Presentation
The Structure of Proteins

The Structure of Proteins

130 Vues Download Presentation
Télécharger la présentation

The Structure of Proteins

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. The Structure of Proteins

  2. What are proteins? Proteins are polymers - large molecules made from many smaller molecules. Each protein molecule is built up from amino acids, smaller monomer molecules that join end to end to make the protein polymer molecule. Each protein has its own number and sequence of amino acids. This gives each protein molecule a particular shape, allowing it to carry out a particular function).

  3. Functions of Proteins • Fibrous proteins – structural, e.g. collagen. • Globular proteins – metabolic functions, e.g. haemoglobin. • It is their structure that allows them to carry out their functions.

  4. Structure of Proteins • Monomer units of proteins are called amino acids.

  5. Structure of Proteins Amino Acids C

  6. Structure of Proteins Amino Acids AMINO GROUP H C N H

  7. Structure of Proteins Amino Acids AMINO GROUP O H H C C N O H CARBOXYLGROUP

  8. Structure of Proteins Amino Acids AMINO GROUP O H H C C N O H CARBOXYL GROUP

  9. H Structure of Proteins Amino Acids AMINO GROUP O H H C C N O H CARBOXYL GROUP

  10. Structure of Proteins Amino Acids H AMINO GROUP O H H C C N O H CARBOXYL GROUP

  11. Structure of Proteins Amino Acids H AMINO GROUP O H H C C N O H CARBOXYL GROUP R-GROUP (Variant)

  12. Structure of Proteins Amino Acids H AMINO GROUP O H H C C N O H CARBOXYL GROUP R-GROUP (Variant)

  13. Structure of Proteins PRIMARY STRCUTURE – Polypeptides • Polypeptides are composed of amino acids bonded to each other, like beads on a string • The bond that holds them together is called a peptide bond • They are formed by loss of water so is called a condensation reaction.

  14. Structure of Proteins PRIMARY STRCUTURE – Polypeptides

  15. Structure of Proteins PRIMARY STRCUTURE – Polypeptides • -OH from carboxyl group • -H from amino group • Forms peptide bond

  16. Functions of Proteins • Fibrous proteins – structural, e.g. collagen. • Globular proteins – metabolic functions, e.g. haemoglobin. • It is their structure that allows them to carry out their functions. • Makes proteins distinctive – interacting with other molecules

  17. Denaturation Denaturation isthe change in structure of protein molecules. The process results in the unfolding of molecules. Factors which contribute to denaturation are heat, salts, pH and mechanical action. Denaturation is a partially reversible change. For example, when an egg white is whisked it incorporates air to form a foam. If the foam is left to stand, it will collapse back to form liquid egg white.