APK 2105C Lecture Notes - Lecture 8: Cell Metabolism, Dephosphorylation, Sucrose
23 May 2018
School
Department
Course
Professor
Chapter 3, Part 1
Cell Metabolism
• Cell metabolism
o Metabolism = sum total of all chemical rxns that occur in cells
o Energy metabolism = rxns involved in energy storage and use
• Chemical rxns 101
o New bonds form and old bonds are broken
o Total mass of reactants equals the total mass of the products
o One sided arrow = net direction of reaction is going that way
• Types of metabolic rxns
o Anabolic = produces larger molecules from smaller reactants
▪ Amino acids → proteins
▪ Glucose → glycogen
o Catabolic = breakdown of larger molecules into smaller products
▪ Glycogen → glucose
▪ Protein → amino acids
o Energy is associated with both of these types of rxns
• Metabolic pathways
o Most metabolic rxns are series of reactions
o Initial reactants → intermediates → end-products
▪ Intermediates may play role in feedback
• Hydrolysis and condensation rxns
o Hydrolysis = splitting with water
▪ A—B + H2O → A—OH + H—B
• Water molecule in reactant side of equation
▪ Sucrose + H2O → glucose + fructose
▪ Catabolic
o Condensation = water forming
▪ A—OH + H—B → A—B + H2O
• Water molecule in product side of equation
▪ Glucose + fructose → sucrose + H2O
▪ Anabolic
o Phosphorylation = addition of a phosphate group
▪ A + Pi (inorganic)→ A—P
▪ ADP + Pi → ATP + H2O (condensation)
o Dephosphorylation = removal of a P group
▪ A—P → A + Pi
▪ ATP + H2O → ADP + Pi (hydrolysis)
• Oxidation-reduction rxns
o Oxidation = removal (losing) of electrons (LEO)
▪ H2 → 2H+ + 2e-
▪ Electrons were removed from this reactant, resulting in formation of
an ion product
o Reduction = acceptance (gaining) of electrons (GER)
▪ H2+ + 2e- → H2
find more resources at oneclass.com
find more resources at oneclass.com
