Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Amino Acids, Peptides, and Proteins: A Comprehensive Overview, Slides of Biochemistry

A comprehensive overview of amino acids, peptides, and proteins, covering their structure, properties, classification, and functions. It delves into the central dogma of molecular biology and protein biochemistry, explaining the relationship between sequence, structure, and function. The document also explores the different levels of protein structure, including primary, secondary, tertiary, and quaternary structures, and the bonds that stabilize these structures. Additionally, it discusses the denaturation of proteins and the factors that can cause it. Finally, the document examines the classification of proteins based on shape, composition, and function, providing examples of each type.

Typology: Slides

2023/2024

Uploaded on 10/28/2024

oanh-nguyen-ngoc
oanh-nguyen-ngoc 🇻🇳

3 documents

1 / 69

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Unit 4
Presented: Tam-Anh Duong Nguyen, PhD
Amino acids, peptides
and proteins
pf3
pf4
pf5
pf8
pf9
pfa
pfd
pfe
pff
pf12
pf13
pf14
pf15
pf16
pf17
pf18
pf19
pf1a
pf1b
pf1c
pf1d
pf1e
pf1f
pf20
pf21
pf22
pf23
pf24
pf25
pf26
pf27
pf28
pf29
pf2a
pf2b
pf2c
pf2d
pf2e
pf2f
pf30
pf31
pf32
pf33
pf34
pf35
pf36
pf37
pf38
pf39
pf3a
pf3b
pf3c
pf3d
pf3e
pf3f
pf40
pf41
pf42
pf43
pf44
pf45

Partial preview of the text

Download Amino Acids, Peptides, and Proteins: A Comprehensive Overview and more Slides Biochemistry in PDF only on Docsity!

Unit 4

Presented: Tam-Anh Duong Nguyen, PhD

Amino acids, peptides

and proteins

Contents of the lesson

  • Part I. Amino acids
  • Part II. Peptides and Proteins
  • Part III. Enzymes

Learning objectives of Part I

  • Describe the structure and properties of

amino acids

  • Classify amino acids

4

Structure of an amino acid

  • Amino acids are the building blocks of proteins.
  • 20 amino acids are used to make every protein on earth.
  • Each amino acid has a carboxyl group (-COOH), an amino group (- NH 2 ) and a distinctive side chain (R) bonded to the α carbon atom (except proline ).

Glycine, the only amino acid with a hydrogen atom as a side chain

Proline contains a secondary amine group (– NH- ), called an imine, instead of a primary amine group (-NH 2 )

  • The two chiral forms of amino acids are called 'D' and 'L’. D and L forms are mirror images of each other ( enantiomers ).
  • Only L-amino acids are found in proteins formed biologically (important!!!).

Optical properties of amino acids

________________

Acid/base properties of amino acids

  • Amino acid has both a basic amine groups and an acidic carboxylic acid group (an ampholyte )  amino acids have both acidic and basic properties.

Isoelectric point (pI)

  • The pI of a molecule is the pH at which its charge is exactly equal.
  • The pI of an amino acid must be calculated precisely as the average of the pKa values on either side of the molecule with a charge of zero.

A titration curve for glycine. The pH controls the charge on glycine: cationic below pH 2.3; zwitterionic between pH 2.3 and 9.6; and anionic above pH 9.6. The isoelectric pH is 6.0.

Classification of amino acids

  • Amino acid can be classified based on:
    • Nutritional requirements
    • Metabolic fate
    • The side chain properties
    • Biosynthetic incorporation into protein
  • Essential amino acids or

indispensable amino acids

  • Non-essential amino acids or

dispensable amino acids

Classification of amino acids based on nutritional requirement

  • Ketogenic amino acids
    • A ketogenic amino acid is an amino acid that can
be converted into ketone bodies through
ketogenesis.
  • Glucogenic amino acids
    • A glucogenic amino acid is an amino acid that
can be converted into glucose through
gluconeogenesis
  • Both ketogenic and glucogenic amino acids :
    • Amino acid can be used for the production of
either glucose or ketone bodies.

Classification of amino acids based on metabolic fate

Amino acids are grouped according to the

properties of their R groups

The R group of amino acids

  • Twenty amino acids are commonly found in

proteins.

  • The properties of the amino acids are

determined by the composition of the R groups

on each of them.

___________