DNA Replication Process

Process: The creation of two identical copies of DNA from one original DNA molecule
Steps:
1. Initiation: Unwinding of DNA at origin of replication, binding of helicase and topoisomerase
2. Unwinding: Separation of DNA strands, creation of replication fork
3. Synthesis: Leading strand synthesis continuous, lagging strand synthesis in short, discontinuous segments (Okazaki fragments)
4. Elongation: Addition of nucleotides to leading strand, RNA primers removed and replaced with DNA
5. Ligation: Sealing of gaps between Okazaki fragments
Enzymes involved: Helicase, topoisomerase, primase, DNA polymerase, ligase

Definition: The process by which the information in a gene's DNA is converted into a functional product (protein or RNA)
Steps:
1. Transcription: Synthesis of RNA from DNA template
2. Translation: Synthesis of protein from RNA sequence
Regulation: Gene expression is regulated at multiple levels, including transcriptional, post-transcriptional, and post-translational
Types of RNA: mRNA (messenger), tRNA (transfer), rRNA (ribosomal), miRNA (micro), siRNA (small interfering)

Definition: The manipulation of an organism's genome using biotechnology
Techniques:
- Recombinant DNA technology: Creation of recombinant DNA molecules by combining DNA from different sources
- Gene cloning: Creation of multiple copies of a gene
- Gene editing: Alteration of a gene's sequence using CRISPR-Cas9 or other methods
Applications: Production of recombinant proteins, gene therapy, genetically modified organisms (GMOs)

Definition: The process by which cells create proteins
Steps:
1. Initiation: Binding of ribosome to mRNA, recognition of start codon
2. Elongation: Addition of amino acids to growing polypeptide chain
3. Termination: Recognition of stop codon, release of completed protein
Components: mRNA, ribosomes, tRNA, amino acids
Types of RNA involved: mRNA, tRNA, rRNA

Definition: The study of heritable changes in gene function that occur without a change in the underlying DNA sequence
Mechanisms:
- DNA methylation: Addition of methyl groups to DNA, typically silencing gene expression
- Histone modification: Addition of various chemical groups to histone proteins, affecting chromatin structure and gene expression
Inheritance: Epigenetic changes can be passed on to daughter cells, but may not be stable across generations
Role in development and disease: Epigenetic changes play a crucial role in cellular differentiation and development, and have been implicated in various diseases, including cancer.

The process creates two identical copies of DNA from one original DNA molecule
Initiation involves unwinding of DNA at origin of replication, binding of helicase and topoisomerase
Unwinding results in separation of DNA strands, creation of replication fork
Leading strand synthesis is continuous, while lagging strand synthesis occurs in short, discontinuous segments (Okazaki fragments)
Elongation involves addition of nucleotides to leading strand, RNA primers removed and replaced with DNA
Ligation seals gaps between Okazaki fragments
Helicase, topoisomerase, primase, DNA polymerase, and ligase are the enzymes involved

Gene expression is the process by which the information in a gene's DNA is converted into a functional product (protein or RNA)
Transcription involves synthesis of RNA from DNA template
Translation involves synthesis of protein from RNA sequence
Gene expression is regulated at multiple levels, including transcriptional, post-transcriptional, and post-translational
There are five types of RNA: mRNA (messenger), tRNA (transfer), rRNA (ribosomal), miRNA (micro), and siRNA (small interfering)

Genetic engineering is the manipulation of an organism's genome using biotechnology
Recombinant DNA technology creates recombinant DNA molecules by combining DNA from different sources
Gene cloning creates multiple copies of a gene
Gene editing involves alteration of a gene's sequence using CRISPR-Cas9 or other methods
Applications include production of recombinant proteins, gene therapy, and genetically modified organisms (GMOs)

Epigenetics is the study of heritable changes in gene function that occur without a change in the underlying DNA sequence
DNA methylation adds methyl groups to DNA, typically silencing gene expression
Histone modification involves addition of various chemical groups to histone proteins, affecting chromatin structure and gene expression
Epigenetic changes can be passed on to daughter cells, but may not be stable across generations
Epigenetic changes play a crucial role in cellular differentiation and development, and have been implicated in various diseases, including cancer