Lecture 1 Biochemistry_Intro and Water

Page 1: Introduction to Biochemistry

• Lecture Title: BIOCH-521 - Lecture 1

• Focus: Introduction & Aqueous Solutions

Page 2: Overview of Biochemistry

• Key Question: What is biochemistry?

• Biochemistry occurs primarily in aqueous solutions, emphasizing the significance of water.

• Lecture Topics to Cover:

  • Weak interactions between molecules, which are fundamental to all biochemical processes.

Page 3: Defining Biochemistry

• Biochemistry is the study of chemical processes in living organisms.

• It encompasses the interactions between:

  • Organisms and their ecosystems

  • Atoms and molecules

  • Cells and organs

• Examples:

  • Sickle Cell disease

  • ATD toxin produced by pufferfish hemoglobin

Page 4: Major Classes of Biochemical Molecules

1. Proteins

   • Composed of polymers of amino acids folded into specific 3D structures.

   • Functions include catalyzing reactions (enzymes), providing structural support, signaling, and mobility.

2. Nucleic Acids

   • DNA and RNA are polymers of nucleotides, pivotal for storing and conveying genetic information.

   • Also involved in energy metabolism (e.g., ATP).

Page 5: Continued Overview of Biochemical Molecules

3. Lipids

   • Comprise hydrophobic hydrocarbons linked to hydrophilic head groups.

   • Functions include cellular membrane formation, energy storage, and cell signaling.

4. Carbohydrates

   • Formed from carbon hydrates (CH2O)n and can create large polymers.

   • Roles include energy storage, structural functions, and serving as components of proteins, nucleic acids, and lipids.

Page 6: The Central Dogma of Molecular Biology

• The Central Dogma (Francis Crick, 1958) explains cellular information processing.

• The flow of information follows the pathway:

  • DNA -> RNA -> Protein

Page 7: Cell Signaling

• Cell Signaling (Signal Transduction)

  • Refers to how physiological stimuli are received by cells, resulting in varied cellular responses.

Page 8: Understanding Metabolism

• Metabolism

  • Encompasses chemical reactions that generate energy and produce biomolecule building blocks.

  • Essential for sustaining life.

Page 9: Summary of Biochemistry Concepts

1. Biochemistry focuses on chemical processes vital for life.

2. Four Major Classes of Biochemical Molecules:

   • Proteins, Nucleic Acids, Lipids, Carbohydrates

3. Understanding the Central Dogma is fundamental: DNA -> RNA -> Protein

Page 10: Transition to Aqueous Solutions

Page 11: Water as a Polar Molecule

• Properties of Water:

  • Water is polar; oxygen carries a slight negative charge (δ-), while hydrogens have a slight positive charge (δ+).

  • Facilitates the formation of hydrogen bonds leading to:

    • Cohesion among water molecules

    • Solubility of polar biomolecules

Page 12: Understanding the Hydrophobic Effect

• Hydrophobic Effect

  • Non-polar molecules aggregate in water, driven by increased entropy.

  • Higher disorder results from hydrophobic molecules clustering together, a vital process for biological systems.

Page 13: Protein Folding and Membrane Formation

• The hydrophobic effect intuitively drives two processes:

  • Protein Folding: Organizing from unstructured to structured states.

  • Membrane Formation: Hydrophilic heads orient towards the water while hydrophobic tails gather inward.

Page 14: Electrostatic Interactions

• Electrostatic Interactions

  • Occur between distinctly charged molecules and can be weakened by the presence of water.

  • Example: Salt bridges commonly found in proteins.

Page 15: Hydrogen Bonding

• Hydrogen Bonds (H-bonds)

  • Non-covalent interactions essential for the stability of structures like the DNA double helix and proteins.

  • Typically occur between hydrogen and electronegative atoms (e.g., O, N).

Page 16: Van der Waals Interactions

• Van der Waals Interactions

  • Weak interactions based on transient charge distributions, stabilizing molecules when closely packed.

  • They are crucial despite being relatively weak compared to other forces.

Page 17: Overview of Biomolecule Interactions

• Four Essential Interactions in Biomolecules

  1. Electrostatic – 40-200 kJ/mol

  2. Hydrogen Bonds – 4-13 kJ/mol

  3. Hydrophobic – 3-10 kJ/mol

  4. Van der Waals – 2-4 kJ/mol

  • Covalent Bonds: significantly stronger (200-400 kJ/mol).

Page 18: Summary of Aqueous Solutions

1. Biochemical interactions predominantly occur in aqueous environments characterized by H-bonds.

2. The hydrophobic effect is crucial, emphasizing entropy-driven processes in biology.

3. Weak interactions (electrostatic, H-bonding, Van der Waals) are integral to biochemical stability.

Page 19: Closing Remarks

• Contact Information: For further inquiries, reach out to dmeekins@ksu.edu.