Review of Macromolecules and Nucleotides

Weight of the Folio and Lipid Macromolecules

Foods are primarily distinguished by their macromolecule content, specifically lipids, carbohydrates, and proteins.

Major Food Groups as Sources of Lipids

Lipid-rich foods include olive oil and butter, which are excellent sources. In contrast, orange juice and fresh fruit are primarily rich in carbohydrates. Chicken breast and tuna fish are good sources of proteins, while pasta and white rice also fall into the carbohydrate category.

Components of Nucleotide Monomer

Essential components of a nucleotide monomer include a nitrogenous base (such as Adenine or Guanine), a pentose sugar (like Ribose or Deoxyribose), and one or more phosphate groups. A fatty acid chain is not a component of a nucleotide monomer.

Phospholipids and Amphipathic Molecules

Phospholipids are described as amphipathic due to their distinct structure. They consist of a charged, hydrophilic (water-attracting) head and possess an uncharged, hydrophobic (water-repelling) tail. It is important to note that phospholipids are not steroids with a four-fused-ring structure, nor are they solely composed of long, nonpolar hydrocarbon chains, and they cannot be converted from unsaturated fat to saturated fat.

Storage Polysaccharide in Plants

The main storage polysaccharide in plants is starch, which comprises two forms: amylose, characterized by its coiled structure, and amylopectin, known for its branched structure. Cellulose, on the other hand, is a structural polysaccharide, not a storage one. Glycogen is the storage polysaccharide found in animals, not plants, and chitin is present in fungal cell walls and the exoskeletons of arthropods.

Informational Macromolecules

DNA is a prime example of an informational macromolecule, as it dictates the amino acid sequence of proteins. Other types of macromolecules mentioned include collagen, which is a structural protein providing strength to connective tissue; cellulose, which contributes to plant cell wall structure; and triglycerides, which are involved in long-term energy storage but not information.

Monomers of Carbohydrates

A monosaccharide is the single-unit building block, or monomer, of carbohydrates and is the basic unit of larger carbohydrates like starch. A nucleotide pertains to nucleic acids, an amino acid is the monomer of proteins, and a fatty acid is related to lipids.

Role of Enzymes in Biological Systems

The primary role of an enzyme is to lower the activation energy required to speed up a chemical reaction. Enzymes are not involved in storing genetic information, forming waterproof layers, or providing long-term energy storage.

Key Role of DNA in Cells

The key role of DNA is to store, transmit, and express hereditary information. It is not a rapid source of energy for cells.