Carbohydrates+and+Proteins+Lecture+Notes

Chapter Overview

• Focuses on the chemistry of life and the importance of organic molecules.

Major Types of Organic Molecules

• Cells contain four major types of organic molecules:

  • Carbohydrates

  • Proteins

  • Nucleic acids

  • Lipids

• Example of an organic molecule: Methane (contains carbon and hydrogen).

Functional Groups in Organic Molecules

• Organic molecules are characterized by functional groups that influence their chemistry:

  • Hydroxyl

  • Carboxyl

  • Amino

  • Phosphate

Biological Importance of Organic Molecules

• Organic molecules are essential for life processes and can be categorized as:

  • Carbohydrates

  • Proteins

  • Nucleic acids

  • Lipids

Dietary Presence of Organic Molecules

• Common in diets:

  • Carbohydrates, proteins, and fats.

• Association with health:

  • Some are considered healthy, while others are linked to obesity, heart disease, and diabetes.

Monomers and Polymers

• Monomers: Single units of organic molecules (carbohydrates, proteins, nucleic acids).

• Monomers join to form polymers.

Dehydration Synthesis

• Definition: Type of chemical reaction that joins monomers by releasing a water molecule.

• Importance: Used to synthesize polymers with the help of enzymes.

Hydrolysis

• Definition: Type of chemical reaction that breaks down polymers by the addition of a water molecule.

• Function: Enables digestion and breakdown of larger organic molecules into monomers.

Carbohydrates

• Types:

  • Monosaccharides: Simple sugars, such as ribose, glucose, and fructose.

  • Disaccharides: Formed from two monosaccharides (e.g., sucrose).

  • Polysaccharides: Long chains; examples include cellulose (structure), starch (energy), and glycogen (energy).

Proteins and Their Functions

• Considered the "workers" of cells, performing various functions:

  • Structural (e.g., collagen)

  • Muscle contraction (e.g., actin and myosin)

Amino Acids

• Building blocks of proteins:

  • 20 different amino acids.

  • All possess the same general structure but differ in their R-groups:

    • Properties: Polar, nonpolar, charged, varying sizes.

Protein Synthesis and Breakdown

• Dehydration synthesis combines two amino acids to form a dipeptide; long chains form polypeptides.

• Hydrolysis breaks down dipeptides and polypeptides into individual amino acids.

Protein Structure

• Folding: Amino acid chains fold into unique 3D shapes, determining protein function.

• Denaturation: Loss of shape leads to loss of function.

Protein Structure Types

• Primary: Sequence of amino acids.

• Secondary: Alpha-helices and beta-sheets.

• Tertiary: Overall 3D shape of a protein.

• **Quatern