Reaction 1: Citrate Synthase. The first reaction of the citric acid cycle is catalyzed by the enzyme citrate synthase. In this step, oxaloacetate is joined with acetyl-CoA to form citric acid. Once the two molecules are joined, a water molecule attacks the acetyl leading to the release of coenzyme A from the complex. Figure %: Reaction 1.
There are three types of carbohydrates: starch, sugar and fiber. Starches and sugars provide your body with its main source of energy. They're all comprised of carbon, oxygen and hydrogen, which are organized into single units.
The simplest form of carbohydrate is glucose. Simple sugars that are found in foods include sucrose (table sugar), fructose (found in fruit), and lactose (found in milk). Not all simple carbs are bad. Natural simple carbs in fruit and milk are perfectly healthy.