PS263 Chapter Notes - Chapter 4: Messenger Rna, Mendelian Inheritance, Cytosine
Document Summary
Mendel demonstrated that inheritance occurs through genes. Genes: units of heredity that maintain their structural identity from one generation to another. Genes come in pairs because they"re aligned along chromosomes that also come in pairs. A gene is de ned as part of a chromosome composed of the double-stranded molecule deoxyribonucleic acid (dna) A strand of dna serves as a template (model) for the synthesis of ribonucleic acid (rna) molecules. Messenger rna serves as a template for the synthesis of protein molecules. Dna contains 4 bases : adenine, cytosine, guanine, thymine. The order of those bases determines the order of corresponding bases along an rna molecule: adenine, cytosine, guanine, uracil. The order of bases along an rna molecule in turn determines the order of amino acids that compose a protein. Some proteins form part of the structure of the body, others serve as enzymes. Enzyme: biological catalyst that regulates chemical reactions in the body.
