How Enzymes Speed Up Reactions?

The effect of an enzyme on activation energy. Without affecting the free-energy change (∆G) for a reaction, an enzyme speeds the reaction by reducing its activation energy (EA). Source: Urry, Lisa A.. Campbell Biology (p. 155). Pearson Education. Kindle Edition. Campbell Biology Proteins, DNA, and other complex cellular molecules are rich in free energy and … Continue reading How Enzymes Speed Up Reactions?

The Activation Energy Barrier

Energy profile of an exergonic reaction. The “molecules” are hypothetical, with A, B, C, and D representing portions of the molecules. Thermodynamically, this is an exergonic reaction, with a negative ∆G, and the reaction occurs spontaneously. However, the activation energy (EA) provides a barrier that determines the rate of the reaction. Source: Urry, Lisa A.. … Continue reading The Activation Energy Barrier

The Lipogenesis

Lipids may follow one of several pathways during metabolism. Glycerol and fatty acids follow different pathways. Source: OpenStax Anatomy and Physiology OpenStax Anatomy and Physiology When glucose levels are plentiful, the excess acetyl CoA generated by glycolysis can be converted into fatty acids, triglycerides, cholesterol, steroids, and bile salts. This process, called lipogenesis, creates lipids … Continue reading The Lipogenesis

What is Lipolysis?

During fatty acid oxidation, triglycerides can be broken down into acetyl CoA molecules and used for energy when glucose levels are low.Source: OpenStax Anatomy and Physiology OpenStax Anatomy and Physiology To obtain energy from fat, triglycerides must first be broken down by hydrolysis into their two principal components, fatty acids and glycerol. This process, called … Continue reading What is Lipolysis?

The Lipid Metabolism

A triglyceride molecule (a) breaks down into a monoglyceride (b). Source: OpenStax Anatomy and Physiology OpenStax Anatomy and Physiology Fats (or triglycerides) within the body are ingested as food or synthesized by adipocytes or hepatocytes from carbohydrate precursors. Lipid metabolism entails the oxidation of fatty acids to either generate energy or synthesize new lipids from … Continue reading The Lipid Metabolism