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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

  1. Lipids

    • Comprise hydrophobic hydrocarbons linked to hydrophilic head groups.

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

  2. 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.