Glucose serves two main purposes for E. coli in a glucose-salts medium. It acts as the primary energy source, being broken down through central metabolism pathways like the EMP pathway and TCA cycle to generate energy. Glucose also provides the carbon that makes up the cell's organic molecules, as E. coli is composed almost entirely of carbon-containing molecules and obtains its carbon mainly from broken down glucose.
Recall that E. coli can grow in glucose-salts medium, which contains .pdf
1. Recall that E. coli can grow in glucose-salts medium, which contains only glucose and a few
inorganic salts. This means the glucose is serving what two purposes in the cell? Starting point
from which all cell components are made Energy source Source of nitrogen A monosaccharide
from that the cell can assemble into polysaccharides such as cellulose for its cell wall Source of
phosphate
Solution
The answer is E.coli, mainly uses glucose as the energy source
Escherichia coli is a heterotrophic organism, carbon is very important to E. coli because the
bacterial cell is composed almost entirely of carbon molecules bound to other important
elements. E. coli's main source of carbon comes from glucose molecules. This is then broken
down into useable carbon by means of central metabolism, which consists of three steps:
1. Embden-Meyerhof-Parnas (EMP) Pathway: converts glucose to pyruvate
2. Tricarboxylic Acid (TCA) cycle: oxidizes Acetyl CoA to CO2
3. Pentose Phosphate Cycle (PPP): oxidizes glucose to CO2