Week 8 Flashcards
Polysaccharides syn from activated glucose. (3)
- Uridine diphosphoglucose (UDPG)
- Adenosine diphosphoglucose
- add active glucose to polymer fragments
Gluconeogenesis
Synthesis of glucose from phosphoenolpyruvate.
Pentose (C5 sugars) formation?
by removal of one carbon atom from a hexose
Purpose of C5?
for synthesis of nucleic acids
What happens in pentose phosphate pathway?
Glucose oxidized to CO2, NADPH, ribulose-5-phosphate
Pentose catabolized through this pathway
Produces several 4-7 carbon sugars
Gen NADPH for deoxyribonucletide and fatty acid biosynthesis
Amino acids, how to obtain?
If not from environment, synthesized from glucose or other carbon sources
How are amino acids grouped? Where do carbon skeletons come from?
Into structural families based on shared biosynthetic steps
Come from intermediates of glycolysis or CAC
Where is amino group from?
Typically from inorganic nitrogen source. Ex. NH3
Amino group from glutamate or glutamine can be transferred by transminase/aminotransferase shuttles
Nucleotides components and construction?
Purine and Pyrimidines
From multiple carbon and nitrogen sources
Purines
Inosinic acid skeleton is precursor to adenine and guanine
Pyrimidines
Uridylate skeleton is precursor to thymine, cytosine, and uracil
Archaea and fatty acids?
Do not contain fatty acids: have hydrophobic isoprenoids instead
Fatty acid biosynthesis:
How many carbons?
How?
Two carbons at a time
Acyl carrier protein holds growing fatty acid during synthesis and releases it
Each C2 acetyl originates from C3 malonate; CO2 released
Can be unsaturated branched or contain odd numbers of carbon atoms
Fatty acid biosynthesis
Fatty acid biosynthesis in diff species/temps? What’s most common in bacteria?
Low temp: shorter, more unsaturated
High temp: Longer, more saturated
Bacteria commonly have C12 -C20 lipids
