BSC2010- Chapter 2 (1)

Chapters Overview

  • Chapter 2803: Che and Biomolec S BSC2010-U04

Carbon

  • Significance in Biological Molecules

    • Primarily consists of:

      • Carbon bonded to carbon

      • Carbon bonded to other molecules

    • Capable of forming up to 4 covalent bonds.

    • Can bond with various functional groups that provide specific properties.

Functional Groups

  • Examples of Functional Groups:

    • Amino Group: -NH2, contributes to the formation of proteins (e.g., Alanine).

    • Hydroxyl Group: -OH, present in carbohydrates, enhances solubility in water.

    • Carboxyl Group: -COOH, found in amino acids and fatty acids, acidic properties.

    • Sulfhydryl Group: -SH, important in protein structure (e.g., Cysteine).

    • Carbonyl Group: -C=O, found in sugars (e.g., Glyceraldehyde).

    • Phosphate Group: -PO4, vital in nucleic acids and energy storage (ATP).

    • Methyl Group: -CH3, affects gene expression.

Biological Molecules

  • Definitions:

    • Monomer: A single subunit (e.g., saccharide, nucleotide, amino acid, fatty acid).

    • Polymer: A large molecule made of multiple monomers (e.g., polysaccharide, nucleic acid, polypeptide, fat).

Synthesis and Breakdown

  • Dehydration Synthesis (Condensation):

    • Formation of large molecules by removing water; monomers join to create polymers.

  • Hydrolysis:

    • Breakdown of larger molecules by adding water; polymers split into monomers.

Carbohydrates

  • Basic Composition:

    • Characterized by a 1:2:1 ratio of Carbon, Hydrogen, and Oxygen with empirical formula (CH2O)n.

    • Examples include sugars, starch, and glucose; energy storage potential.

  • Disaccharides:

    • Comprised of 2 monosaccharides linked by dehydration synthesis (e.g., sucrose, lactose, maltose).

  • Polysaccharides:

    • Long chains of monosaccharides used for energy storage (e.g., starch in plants, glycogen in animals) and structural support (e.g., cellulose in plants, chitin in animals).

Nucleic Acids

  • Types:

    • Three main types: DNA, RNA, and ATP (nTP).

  • Functions:

    • Specialized for the storage, transmission, and use of genetic information; polymers of nucleotides.

  • Nucleotide Composition:

    • Consists of a pentose sugar, phosphate group, and nitrogenous base.

    • DNA: contains deoxyribose, nitrogenous bases (Adenine, Thymine, Cytosine, Guanine).

    • RNA: contains ribose, nitrogenous bases (Adenine, Uracil, Cytosine, Guanine).

Protein Structure

  • Functions of Proteins:

    • Enzyme catalysts, defense mechanisms, transport, support, motion, regulation, and storage.

  • Amino Acids:

    • Building blocks of proteins; 20 different amino acids; linked by peptide bonds through dehydration synthesis.

Protein Structures**

  • Primary Structure:

    • Sequence of amino acids in a polypeptide chain.

  • Secondary Structure:

    • Interaction of peptide backbone groups resulting in alpha helices and beta sheets.

  • Tertiary Structure:

    • Overall three-dimensional shape of a polypeptide, determined by R group interactions.

  • Quaternary Structure:

    • Interactions between multiple polypeptide subunits to form a complete protein.

Lipids

  • Definition:

    • Group of hydrophobic molecules with a high proportion of nonpolar C-H bonds, insoluble in water.

  • Types of Lipids:

    • Fats (triglycerides) and phospholipids.

  • Triglycerides:

    • Composed of one glycerol and three fatty acids; ideal for energy storage due to high energy retention.

  • Phospholipids:

    • Composed of one glycerol, two fatty acids, and a phosphate group, essential for cell membranes.

Summary of Macromolecules**

  • Macromolecule Subunits:

    • Carbohydrates: Subunit: Glucose; Functions: Energy storage.

    • Nucleic Acids: Subunit: Nucleotides; Functions: Gene encoding and expression.

    • Proteins: Subunit: Amino acids; Functions: Catalysis, transport, support.

    • Lipids: Subunit: Glycerol and fatty acids; Functions: Energy storage, membrane formation.