biosynthesis of macromolecules anabolism - use energy (atp) from catabolism - use carbon from...
TRANSCRIPT
Metabolism
Catabolism
Energy (ATP)Small molecules (precursors)
Anabolism
Large molecules
Biosynthesis of Macromolecules
Anabolism- use energy (ATP) from catabolism
- use carbon from sugars, lipids, proteins, or any other carbon source (xenobiotics) to build cellular components
Key Intermediates
• Located in the glycolytic pathway– Ex. Glucose-6-phosphate, pyruvic acid, etc.
• Located in the TCA cycle– Ex. Oxaloacetic acid, ketoglutaric acid
Central Metabolic pathway
• Catabolism and anabolism are interconnected due to amphibolic pathways
Lipid Biosynthesis• Fatty acid biosynthesis- Acetyl-CoA---
>fatty acid (cell structure)
• Poly-ß-hydroxybutyric acid- Acetyl-CoA---> Poly. (storage)
• Phospholipid- Glycolytic intermediate---> lipid ( membrane)
• Sterols- eukaryotic cell membrane
Amino Acid Biosynthesis• Amination – addition of an amine group (N
containing) to a critical intermediate
• Transamination - new amino acids are made from the amine group from old amino acids
Nucleotide Biosynthesis• N molecule (amino acid), five carbon
sugar, phosphate combine =>nucleotides (DNA, RNA)
• Five carbon sugar– Pryrimidines- cytosine, thymine– Purines- adenine, guanine
Polysaccharide Biosynthesis
• Peptidoglycan- Glycolytic intermediates, nucleotides --->PEG
• Lipopolysaccharide- Glycolytic intermediates, other sugars ---> LPS, teichoic acid, mycolic acid, glycogen, etc.
Photosynthetic microbes• Carbon dioxide fixation
– Inorganic CO2 is incorporated into the cellular structure (Calvin cycle)
Metabolic diversity
• Different sources of carbon and energy exist for various microbes, plants, and animals.
Metabolic diversity
Four main groups of microbes
1.) chemoheterotrophs
2.) chemoautotrophs
3.) photoautotrophs
4.) photoheterophs
Chemoheterotrophs
• Many medically important microbes are in this category (E. coli, B. anthrasis, etc.)
• Carbon source = organic molecules (carbohydrates, proteins, lipids, xenobiotics)
• Energy source=organic molecules (carbohydrates, proteins, lipids, xenobiotics)
Chemoautotroph
• Many soil microbes
• Source of carbon = inorganic molecule (ex. CO2)
• Source of energy = electrons from inorganic compounds (ex. S, H2S, NO2)
Photoautotroph
• Photosynthesis (green sulfur bacteria, etc.)
• Source of carbon = CO2
• Source of energy = light
Photoheterotroph
• photosynthesis (green nonsulfur bacteria, etc.)
• Source of carbon = organic molecule ( ex. Fatty acids, alcohol, etc.)
• Source of energy = light
Summary of Anabolism
• Use ATP (energy) from catabolism for biosynthesis
• Build small molecules into larger molecules or cell structures (ex. Glucose, amino acids, fatty acids=>lipid, PG)
• Diversity of metabolic systems (chemoheterotrophs, etc.)
• Cell division (binary fission)=anabolism
• Catabolism and anabolism are integrated
• (amphibolic pathways)