41. Anabolism, industrial examples**

Question 1

what is the relevance of anabolism in industrial applications?

Answer 1

• macromolecules produced by microbial cell
  – contribute to growth/survival harnessed for industrial application
• products:
  – biomass
  – metabolites

Question 2

what is primary metabolism?

Answer 2

• balanced growth of microorganism
  – all nutrients required by cell are available in excess in medium
• cells grow at exponential rate
  – mode of reproduction kept
  – maintained optimal levels of various macromolecules
• proportions change
  – cell growth progresses and slows down
• depleted essential nutrients
  – growth rate stops
  – metabolism does not stop
• stay alive
  – carry out some metabolic activity
  – metabolism stops when cell dies

Question 3

what is secondary metabolism?

Answer 3

• maintain carbon flux when active replication has ceased
  – divert core metabolites into produces other than primary ones
  – no longer needed in same abundance
• maintenance still required
  – replacement of key proteins
  – DNA repair
  – RNA maintenance
• no synthesis of new products during primary metabolic growth
• often synthesised from unwanted monomers produced during glucose / fatty acid catabolism
  – acetyl-CoA
• fxn of metabolites not certain
  – not produced to great extent (not required for growth / replication)
• possible metabolite roles
  – fulfill functional role contributing to survival of cell in natural environment
  – competition with other organisms
  – response to stimulus
  – difficult to mimic in lab
  – have no value to cell