Exploring DNA, Genetics, and the Human Genome Project
DNA, Genes, and Proteins
Key Concepts
- DNA (Deoxyribonucleic Acid): A molecule composed of four repeating units (cytosine, guanine, thymine, and adenine) combined in various sequences.
- Nucleotides: The building blocks of DNA, consisting of a phosphate group, a sugar, and a nucleobase.
- Proteins: Essential molecules for life, formed by chains of amino acids. There are 20 different amino acids.
- Gene: A segment of DNA that codes for a specific protein. It’s the basic unit of genetic information.
- Karyotype: The complete set of chromosomes in an organism.
- Genotype: The genetic makeup of an organism for a specific trait.
- Phenotype: The observable expression of the genotype.
- Chromosome: A structure composed of DNA and proteins, carrying genetic information.
- Ribosomes: Cellular structures responsible for protein synthesis.
- Mutation: A change in the DNA sequence.
- Pathogenic Mutation: A mutation that causes significant changes in proteins and can lead to diseases.
- Polymorphism: A mutation in a non-coding region of DNA or within a gene that doesn’t cause a significant change in the protein.
Biotechnology and Genetic Engineering
Key Concepts
- Biotechnology: Techniques using biochemical processes of microorganisms to improve food processes.
- Genetic Engineering: The manipulation and transfer of DNA between organisms to create new traits.
- Transgenic Organism: An organism with modified genetic material, often through the introduction of a foreign gene.
- Transgenic Plants: Plants modified with foreign genes to enhance specific traits.
- Transgenic Animals: Animals modified with foreign genes, often through microinjection.
- Stem Cells: Undifferentiated cells with the potential to develop into various cell types.
- Clone: Organisms with identical genetic material.
The Human Genome Project (HGP)
Overview
The HGP is an international project aiming to map and sequence the entire human genome.
Goals
- Create detailed maps of human chromosomes.
- Develop efficient and cost-effective sequencing techniques.
- Develop tools for data storage and analysis.
Achievements and Challenges
The HGP achieved a draft of the human genome in 2000. The private company Celera Genomics also played a significant role in completing the sequencing. The project’s findings were published in “Nature” and “Science.”
Ethical and Legal Implications
The HGP raised several ethical debates:
- Genetic Privacy: Protecting individuals’ genetic information.
- Genetic Discrimination: Preventing discrimination based on genetic predispositions in employment and insurance.
- Genetic Testing in Clinical Settings: Addressing the implications of diagnosing incurable diseases and the “right not to know.”
DNA Replication and Protein Functions
DNA Replication
DNA replication involves DNA polymerases, enzymes that join nucleotides to create new DNA strands based on the existing template. The double helix separates, and polymerases add complementary nucleotides to each strand, resulting in two identical DNA molecules.
Functions of Proteins
- Provide structure, support, and waterproofing.
- Transport substances.
- Activate defense mechanisms.
- Enable movement.
- Package genetic material.
- Transmit signals.
- Facilitate biochemical reactions.