Week 2 Lecture 2 - Biological reactions PDF

BCH2000 – Biochemistry I WEEK 2 – BIOLOGICAL REACTIONS Learning Goals Analyze of the likelihood of different functional groups to participate in chemical reactions and affinity for other functional groups Describe how different functional groups participate in a...

BCH2000 – Biochemistry I WEEK 2 – BIOLOGICAL REACTIONS Learning Goals Analyze of the likelihood of different functional groups to participate in chemical reactions and affinity for other functional groups Describe how different functional groups participate in acid-base reactions Explain how different functional groups participate in reduction-oxidation reactions Functional Group Review Only a types of functional groups contribute to the majority of biochemical reactions: Functional Group Review These key functional groups are found in several key kinds of compounds Functional Group Review These key functional groups combine to form biologically active linkages: Learning Goals Analyze of the likelihood of different functional groups to participate in chemical reactions and affinity for other functional groups Describe how different functional groups participate in acid-base reactions Explain how different functional groups participate in reduction-oxidation reactions pH dependence of biochemical reactions 1- Enzyme activity Different enzymes have different optimal pH conditions, dependent on the location Pepsin is in the stomach Amylase is in saliva Arginase in the kidneys  pH dependence of biochemical reactions 2- Molecular Interactions Interactions between biological species can be determined by pH pH dependence of biochemical reactions 3- Solubility pH will determine the surface charge of molecules (via protonation and deprotonation) which can determine solubility This enzyme is most soluble when there is a net positive (basic conditions) or negative (acidic conditions) charge. When the species is neutral (ie: at isoelectric point) it is least soluble Learning Goals Analyze of the likelihood of different functional groups to participate in chemical reactions and affinity for other functional groups Describe how different functional groups participate in acid-base reactions Explain how different functional groups participate in reduction-oxidation reactions REDOX REDOX REDOX OIL RIG: Oxidation is Loss, Reduction is Gain electrons Reduction Oxidation Performed by “Oxidizing Agent” Performed by “Reducing Agent” Oxidizing agent is Reduced Reducing agent is Oxidized Gain of electrons Loss of electrons Loss of oxygen Gain of oxygen Putting it all together Name: Carboxylic Acid Hydrogen bond donor? Yes- hydroxide H Hydrogen bond acceptor? Yes- Hydroxide and carbonyl Oxygen Changes under acidic conditions: Hydroxide is protonated Changes under basic conditions: Hydroxide is deprotonated How oxidized/reduced is it? Very Oxidized Combinations with other functional groups? Will combine with an amine to form an amide