Transcript Biosynthesis of Macromolecules

Metabolism
Large molecules
Catabolism
Anabolism
Energy (ATP)
Small molecules (precursors)
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)