Biology: Nucleic Acids and Carbohydrates

Study Notes

Definition: Nucleic acids are biomolecules that contain the genetic instructions used in the development and function of all living organisms.
Types:
- DNA (Deoxyribonucleic acid): found in the nucleus of eukaryotic cells and in the cytoplasm of prokaryotic cells. It is a double-stranded helix made up of nucleotides.
- RNA (Ribonucleic acid): found in the cytoplasm of cells. It is a single-stranded molecule made up of nucleotides.
Structure:
- Nucleotides are composed of:
  - Sugar molecule (deoxyribose in DNA, ribose in RNA)
  - Phosphate group
  - Nitrogenous base (A, C, G, T, or U)
- The sugar and phosphate molecules make up the backbone of the nucleic acid, while the nitrogenous bases project inward from the backbone and pair with each other in a complementary manner.
Functions:
- Storage of genetic information
- Transmission of genetic information from one generation to the next
- Synthesis of proteins and other biomolecules

Definition: Carbohydrates are biomolecules that serve as energy sources for cells and provide structural support for organisms.
Types:
- Monosaccharides: simple sugars, such as glucose, fructose, and galactose.
- Disaccharides: composed of two monosaccharides, such as sucrose and lactose.
- Polysaccharides: composed of three or more monosaccharides, such as starch, glycogen, and cellulose.
Structure:
- Monosaccharides have a general formula of C6H12O6.
- Carbohydrates can be classified as either aldoses or ketoses, based on the presence of an aldehyde or ketone group.
Functions:
- Energy source for cells
- Structural support for cells and organisms (e.g., cellulose in plant cell walls)
- Component of nucleic acids and other biomolecules