Anabolism of Biomolecules Part II: Cellular and Molecular Biology

Lipid Metabolism and Anabolism

• Lipid anabolism is also known as lipogenesis.
• When glycerol binds with fatty acids, triglycerides are formed.

Nucleotide Synthesis

• The major site for purine nucleotide synthesis is the liver.
• Nucleosides consist of a nitrogenous base and a sugar (ribose or deoxyribose).
• The catalyst for the initial reaction in pyrimidine nucleotide biosynthesis is carbamoyl phosphate synthetase II.
• Nucleotides are composed of a nitrogenous base, a sugar, and one or more phosphate groups.
• PRPP (phosphoribosyl pyrophosphate) is crucial in pyrimidine biosynthesis as it provides the ribose sugar necessary for nucleotide formation.

Energy Production and Electron Carriers

• NADH and FADH2 produced during β-oxidation and fatty acid synthesis contribute to the electron transport chain for ATP production.

Nucleotide Types

• Purines include adenine and guanine; pyrimidines include cytosine, thymine, and uracil.
• Leukocytes (white blood cells) such as neutrophils cannot produce purines.
• The synthesis of purine nucleotides is essential for DNA and RNA synthesis.

Biosynthesis Processes

• Nucleotide biosynthesis occurs through de novo or salvage pathways, with de novo originating from amphibolic intermediates.
• Fatty acids are converted to CoA thioesters through a process called fatty acid activation.

Fatty Acid Transport and Activation

• Fatty acyl CoA molecules are transported into mitochondria via carnitine shuttle.
• In fatty acid activation, ATP is hydrolyzed to form 2 Pi (inorganic phosphates).

Fatty Acid Catabolism

• The catabolic process in mitochondria that breaks down fatty acid molecules to produce acetyl-CoA is β-oxidation.
• Key enzymes involved in β-oxidation include acyl-CoA dehydrogenase and beta-hydroxyacyl-CoA dehydrogenase.
• The enzyme responsible for converting fatty acyl CoA to acylcarnitine is carnitine acyltransferase I.

This quiz covers various topics related to the anabolism of biomolecules, including the metabolism of carbohydrates, fatty acids, amino acids, nucleotides, lipids, and the oxidation of fatty acids. It also touches on processes such as activation of fatty acids at the outer mitochondrial membrane and degradation of acetyl CoA in the mitochondrial matrix.