Microbial Metabolism (Part 2)

• Glycolysis

  • The oxidation of glucose to pyruvic acid, produces 2 ATP and 2 NADH
• Preparatory stage

  • 2 ATP are used
  • Glucose is split to form 2 Glucose-3-phosphate
• Energy-conserving stage

  • 2 Glucose-3-phosphate oxidized to 2 pyruvic acid
  • 4 ATP produced
  • 2 NADH produced
• Pentos Phosphate Pathway

  • Cytoplasm
  • No ATP directly produced
  • An alternative metabolic pathway when cells don't need ATP.
• Two phases of PPP

  • Oxidative phase
  • Non-oxidative phase
• Enter-doudoroff pathway

  • Notable in gram - bacteria
  • Only in prokaryotes
  • Produces: 1 ATP, 1 NADH, 1 NADPH
• Intermediate step

  • Pyruvic acid (from glycolysis) is oxidized and decarboxylated
• Krebs Cyle

  • All end products will be TWO
  • 2 Co2 - 4
  • 3 NADH - 6
  • 1 FADH2 - 2
  • 1 ATP - 2
• Electron Transport Chain

  • Series of protein complex
  • Moving electrons across to establish electrochemical gradient
• Chemiosmosis - The movement of ions across a selectively permeable membrane, down their electrochemical gradient.
• Deamination - the amino group is removed and converted to ammonium ion
• decarboxylation - the removal of carboxyl group
• dehydrogenation - removal of hydrogen
• Biochemical tests and Bacterial identification

  • used to identify bacteria
• Photosynthesis

  • the process by which green plants and some other microorganisms use sunlight to synthesize foods from carbon dioxide and water
• Chloroplast - contains chlorophyll, which absorbs light energy for photosynthesis
• Chlorophyll - green pigment in chloroplasts that absorbs light energy
• Light-dependent reaction (Light)

  • Photo: conversion of light energy to chemical (ATP)
• Light-independent reaction or Calvin Benson Cycle

  • synthesis: fixing carbon into organic molecules
• Halobacterium

  • uses bacteriorhodopsin to generate electrons for a pump chemiosmotic proton pump
• Phototrophs - organisms that use light energy to make their own food.
• Photoautotrophs - uses light as a source of energy and carbon dioxide as their source of carbon
• Oxygenic - photosynthetic process that produces oxygen
• Anoxygenic - cannot carry on photosynthesis when oxygen is present
• Bacteriochlorophylls

  • Green sulfur bacteria - vesicles called Chlorosomes
  • Violet sulfur bacteria - inavignation of the plasma membrane called Chromatophores
• Photoheterotrophs

  • use light as source of energy but cannot convert carbon dioxide to sugar
  • they use sources of carbon organic compounds, such as alcohols, fatty acids, and other organic acids, and carbohydrates
• Green non-sulfur bacteria - Chloroflexus
• Violet non-sulfur bacteria - Rhodopseudomonas
• Chemotrophs - depend on oxidation-reduction reactions of inorganic or organic compounds for energy
• Chemoautotrophs

  • energy used in the Calvin-Benson cycle to fix CO2
• chemoheterotrophs

  • energy used in anabolism
• Saprophytes - live on dead organic smaller
• parasites - derive nutrients from living hosts