Essential Concepts in Molecular Biology and Cell Division

Posted on Jan 13, 2025 in Biology

Key Terms

• Codon: The amino acid coding unit in DNA or messenger RNA. Each codon corresponds to a specific amino acid, and the string of codons in mRNA specifies the order of amino acids in the encoded protein.
• Nucleic Acid: Naturally occurring chemical compound that is capable of being broken down to yield phosphoric acid, sugars, and a mixture of organic bases. The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
• Nucleotide: The basic building block of nucleic acids. A nucleotide consists of a sugar molecule (either ribose in RNA or deoxyribose in DNA) attached to a phosphate group and a nitrogen-containing base.
• Chromatin: The material of which the chromosomes of organisms other than bacteria are composed, consisting of protein, RNA, and DNA.
• Genetic Code: The set of rules used by living cells to translate information encoded within genetic material (DNA or mRNA sequences) into proteins.
• Cytokinesis: The division of the cytoplasm and the plasma membrane following the division of the nucleus, resulting in two cells, each having its own nucleus and cytoplasm surrounded by a plasma membrane.
• Diploid Organisms: They have two sets of chromosomes.
• Haploid Cells: One cell has a single set of chromosomes.
• Proteins: Large molecules created by small molecules (amino acids) linking together to form a chain.

Key Processes

• DNA Replication: Process by which an identical copy of each of the strands that form the DNA is made.
• Transcription: The first of several steps of DNA-based gene expression in which a particular segment of DNA is copied into RNA (especially mRNA) by the enzyme RNA polymerase.
• Translation: The process in which ribosomes in the cytoplasm or endoplasmic reticulum synthesize proteins after the process of transcription of DNA to RNA in the cell’s nucleus. The entire process is called gene expression.
• Mitosis: The process of cell division in which cells are obtained to repair and grow tissues.
  • Prophase: The chromatin fibers that were replicated during interphase form chromosomes.
  • Metaphase: The chromosomes reach maximum condensation.
  • Anaphase: The sister chromatids of each chromosome separate as they are dragged by the spindle apparatus filament.
  • Telophase: The daughter chromosomes migrate to the end of the corresponding cell.
• Meiosis: Process in which gametes are obtained in order to form reproductive cells.
• Somatic Cells: Cells that form the body of organisms; they are diploid (2n) cells.
• Germ Cells: Diploid cells that produce haploid (n) sex cells.

Differences Between DNA and RNA

Differences Between Mitosis and Meiosis