BIOL1040 Lecture Notes - Lecture 2: Catabolism, Pyruvic Acid, Glycolysis
INTRODUCTION TO METABOLISM
LEARNING GOALS
• Broad overview of the metabolic pathways
o Catabolism vs anabolism
o How they can be regulated
o Common metabolic end products
o Anabolic and catabolic processes can be localised to different areas of the cell
• Metabolism
o All the pathways are connected
• Energy currency of the cell
o ATP
o Structure of ATP/ADP
o Why is it a good energy currency
• Reduced co-enzymes – NADH, NADPH, FADH
o General structure
o Role in the cell
PATHWAYS ARE CONSERVED AMONGST THE KINGDOMS OF LIFE
• Many pathways are present in all organisms
• Glycolysis – glucose is broken down to release energy in the form of ATP
o Probably the most ancient of pathways
o Present in almost all organisms
CATABOLISM VS ANABOLISM
• Catabolic pathways – energy yielding
o Oxidative degradation of complex nutrients from the environment or cellular reserves
• Carbohydrates(sugars)
• Proteins
Lipids(fats)
o Breakdown of complex molecules into simpler molecules
• Gluosearostruture→CO
o Exothermic reactions which often generate ATP (NADH)
• Anabolic pathways – energy requiring
o Synthesis of biomolecules (proteins, lipids, polysaccharides, nucleic acids) from simpler
compounds
o Uses energy ATP, NADPH
• The energy released from catabolism is less than the energy required to generate the same
compound through anabolism
o Glucose → pruvate geerates ATP oleules glolsis
o Pruvate → gluose uses ATP oleules gluoeogeesis
• Catabolism and anabolism occur in the same cell
o Tight regulation of both catabolism and anabolism
o Localised the reactions in different compartments of the cell – fatty acid oxidation
occurs in the mitochondria, fatty acid biosynthesis occurs in the cytosol
• Enzymatic pathways can be
o Separate and substrates diffuse between the enzymes
o Multi-enzymatic complexes
o Membrane bound
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Document Summary
Catabolism vs anabolism: catabolic pathways energy yielding, oxidative degradation of complex nutrients from the environment or cellular reserves, carbohydrates(sugars, proteins. Lipids(fats: breakdown of complex molecules into simpler molecules, glu(cid:272)ose(cid:894)(cid:1010)(cid:272)ar(cid:271)o(cid:374)stru(cid:272)ture(cid:895) co(cid:1006, exothermic reactions which often generate atp (nadh, anabolic pathways energy requiring. Some intermediates are present in both catabolic and anabolic reactions (amphibolic intermediates) Are the pathways of catabolism and anabolism different: pathways do not match exactly, glu(cid:272)ose p(cid:455)ruvate (cid:894)ge(cid:374)erates 2 atp molecules) (glycolysis, p(cid:455)ruvate glu(cid:272)ose (cid:894)uses (cid:1008) atp (cid:373)ole(cid:272)ules(cid:895) (cid:894)glu(cid:272)o(cid:374)eoge(cid:374)esis(cid:895, may have common intermediates but some different enzymes. Because they are going in different directions they need to be differentially regulated. Regulation of ten occurs at rate limiting steps and these enzymes are unique to each pathways. Interacts with a large variety of different compounds/reactions. Energy state of the cell is indicated by the ratio of atp:adp:amp: although atp is turned over levels do not change significantly. Atp, adp and amp sometimes regulate energy breakdown and storage.