Sweeter than a woman’s kiss 🙂 Glucose is the most important sugar in biology! The name comes from the Greek glukus (γλυκύς), meaning “sweet”. The suffix “-ose” denotes a sugar.
Biochemistry: Carbs are polymers of glucose, either exclusively (starch, glycogen) or in combination with other simple sugars like fructose and galactose (found in table sugar and milk sugar). These polymers are broken down during digestion before being absorbed in the intestine. Insulin is the signal for clearing glucose from blood into the liver, fat or muscle, where it is converted back into a polymer (glycogen).
Energetics: Glucose is completely broken down to carbon dioxide and water by cellular respiration: C6H12O6 +6O2 → 6CO2 and 6H2O. This process makes ATP, which is then used to power all energy requiring processes in the body. One gram of glucose yields about 3.75 kilocalories of energy.
When your muscles can’t get hold of oxygen fast enough, as in strenuous exercise, glucose is broken down only partially to lactate (“-ate” denotes acid). The old view of lactate as “bad” has been revised drastically. We now know that lactate can fuel neurons to establish memory and that muscles actively burn lactate in the mitochondria to make ATP.
History: Emil Fischer, a German chemist, received the 1902 Nobel Prize in Chemistry for describing the structure of glucose.
Cool Science: Professor Jin Zhang, a Chemical and Biochemical Engineering professor from the University of Western Ontario, has engineered nanoparticles into contact lenses that react with the glucose molecules contained in tears.When sugar levels rise or fall in a diabetic, a chemical reaction causes the lens to change color, allowing the wearer to adjust their glucose accordingly. (Minor problem: wearer has to check mirror frequently and risk being considered vain!)
Geeky Confessions: I play this song to my first year PhD and medical student class before I talk about glucose transporters. Not all of them get the connection to the old Archies song (sigh). It was the 1969 hit single of the year. Here it is, tambourine and all: http://youtu.be/VwMH0Xzs0IU
This song is for Martha E Fay, who ate birthday cake for breakfast today.
For #ScienceSunday curated by Allison Sekuler and Robby Bowles .