Short answers, pulled from the story.
Chemists identified thiamine as the first vitamin in 1926. This discovery marked a turning point in how scientists understood food and shifted focus from general diet to specific chemical components.
A single gram of fat provides nine calories of energy while one gram of carbohydrate or protein yields four calories. Glucose serves as the simplest form of carbohydrate for most animals and plants synthesize these sugars during metabolism.
Autotrophs produce their own nutrients from inorganic substances like carbon dioxide while heterotrophs obtain carbon by consuming other organisms directly. Some plankton function as mixotrophs switching between both strategies depending on availability.
The Holocene period brought a major divergence with the Neolithic Revolution when humans developed agriculture to produce food rather than hunting it. Cultivation of cereals and bread production became key components of this new diet.
Bacteria perform nitrogen fixation because most plants cannot use atmospheric nitrogen directly. Roots pump hydrogen ions into the soil to displace cations attached to negatively charged particles and phosphorus enter plants as phosphates.