bio unit 1 quiz #2 - buffers, redox, functional groups, linkages

Buffers

• Blood pH range: 7.35–7.45

• Why does pH matter?

• Enzymes function within a narrow pH range

• Protein structure and function depend on pH

• Metabolic and cellular processes are pH-sensitive

• What is a buffer?

  • A buffer is a substance that resists a change in pH when an acid or base is added. 

  • In biological systems, a buffer system functions to regulate the pH of the internal environment

  • Contains weak acid, and the salt of the acid

• Why are buffers important in biological systems?

  • Maintains a narrow pH

  • Significant changes can be fatal
    

• Buffer systems under stress

  • Add acid (proton donor) → H+ concentration increases, pH decreases (temporarily)

  • Add base (proton acceptor) → H+ concentration decreases, pH increases (temporarily)

CH3COO (Acetate)

CH3COOH (Acetic Acid)

CH3COONa (Sodium Acetate)

Redox

What are Redox Reactions?

• Electron transfer reactions (usually a hydrogen atom)

• When electrons are transferred, the potential energy is also transferred

  • Electrons are transferred from a substance with low  ⃤ EN → high  ⃤ EN

• Must be accompanied by reduction because electrons lost by one atom must transfer to another atom

• Why are Redox reactions important?

  • Allows energy to be transferred from one molecule to another

    • Prevents excess heat loss

  • In cycling metabolic processes of photosynthesis and cellular respiration

• Definition

  • Oxidation is the loss of electrons by an atom

    • Also loses H atom

  • Reduction is the gain of electrons by an atom

    • Also gains H atom

      • LEO (lose electrons oxidation) and GER (gain electrons reduction)

Functional Groups

Define functional groups

• A grouping of atoms attached to a carbon backbone of organic molecules

• Responsible for giving the molecule its properties

• Carbon can produce a huge diversity of stable compounds necessary to life

Linkages

• Anhydride linkages (double bond with O)

  • Carboxyl anhydride linkage

  • Phosphoanhydride linkage 
    

• Ether linkages

  • Connect two hydrocarbon groups through an oxygen atom

• Ester linkages

  • Same as ether but one carbon has a double bond with O as well

    • Ex.