Biology DNA Replication and RNA Transcription

Definition: The process of copying DNA to produce two identical DNA molecules.
Key Enzymes:
- DNA Polymers: Synthesizes new DNA strands.
- Helicase: Unwinds the DNA double helix.
- Primase: Synthesizes RNA primers for initiation.
- Ligase: Joins Okazaki fragments on the lagging strand.
Process:
1. Initiation: Helicase unwinds the DNA.
2. Elongation: DNA Polymerase adds nucleotides complementary to the template strand.
3. Termination: Completion of the strands, resulting in two identical DNA molecules.

Definition: The process of synthesizing RNA from a DNA template.
Key Enzymes:
- RNA Polymerase: Catalyzes the transcription process.
Process:
1. Initiation: RNA polymerase binds to the promoter region on DNA.
2. Elongation: RNA strands are formed by complementary base pairing.
3. Termination: RNA polymerase reaches a terminator sequence, releasing the RNA transcript.

Definition: The process by which proteins are synthesized from amino acids based on the genetic code.
Stages:
1. Transcription: Formation of messenger RNA (mRNA) from DNA.
2. Translation:
  - mRNA attaches to ribosomes.
  - Transfer RNA (tRNA) brings amino acids to the ribosome.
  - Ribosomes facilitate the bonding of amino acids into a polypeptide chain.

Polymerase Chain Reaction (PCR): Amplifies specific DNA segments.
Gel Electrophoresis: Separates DNA, RNA, or proteins by size.
DNA Sequencing: Determines the precise order of nucleotides in DNA.
CRISPR-Cas9: A gene-editing tool that allows for precise alterations in DNA.

Definition: Controls the timing and rate of gene expression.
Mechanisms:
- Transcriptional Control: Involves enhancers, silencers, and transcription factors.
- Post-transcriptional Control: Includes mRNA splicing, editing, and translation regulation.
- Epigenetic Modifications: DNA methylation and histone modification can alter gene accessibility.

Amino Acids: Building blocks of proteins, linked by peptide bonds.
Levels of Structure:
1. Primary: Sequence of amino acids.
2. Secondary: Alpha-helices and beta-pleated sheets formed by hydrogen bonding.
3. Tertiary: 3D structure formed by interactions among R groups.
4. Quaternary: Assembly of multiple polypeptide chains.

Classification: Fatty acids, triglycerides, phospholipids, steroids.
Functions:
- Energy storage
- Insulation and protection
- Structural components of cell membranes

Types:
- Saturated: No double bonds, solid at room temperature (e.g., butter).
- Unsaturated: One or more double bonds, liquid at room temperature (e.g., olive oil).
Roles: Energy source, hormone production, and cellular membrane structure.

Monosaccharides: Simple sugars (e.g., glucose, fructose).
Disaccharides: Two monosaccharides linked (e.g., sucrose).
Polysaccharides: Long chains of monosaccharides (e.g., starch, glycogen, cellulose).
Functions: Energy source, structural components, and cell recognition.

Shape: Double helix composed of two strands.
Components:
- Nucleotides: Made of a sugar (deoxyribose), phosphate group, and nitrogenous base (adenine, thymine, cytosine, guanine).
- Base Pairing: Adenine pairs with thymine (A-T), cytosine pairs with guanine (C-G).
Antiparallel Strands: One strand runs 5' to 3', while the other runs 3' to 5', crucial for replication and transcription.

Duplicates DNA to produce two identical DNA molecules
Key Enzymes:
- DNA Polymerase: Synthesizes new DNA strands
- Helicase: Unwinds the DNA double helix
- Primase: Synthesizes RNA primers for initiation
- Ligase: Joins Okazaki fragments on the lagging strand
Process:
- Initiation: Helicase unwinds the DNA
- Elongation: DNA Polymerase adds nucleotides complementary to the template strand
- Termination: Completion of the strands, resulting in two identical DNA molecules

Synthesizes RNA from a DNA template
Key Enzymes:
- RNA Polymerase: Catalyzes the transcription process
Process:
- Initiation: RNA polymerase binds to the promoter region on DNA
- Elongation: RNA strands are formed by complementary base pairing
- Termination: RNA polymerase reaches a terminator sequence, releasing the RNA transcript.

Controls the timing and rate of gene expression
Mechanisms:
- Transcriptional Control: Involves enhancers, silencers, and transcription factors
- Post-transcriptional Control: Includes mRNA splicing, editing, and translation regulation
- Epigenetic Modifications: DNA methylation and histone modification can alter gene accessibility

Amino Acids: Building blocks of proteins, linked by peptide bonds
Levels of Structure:
- Primary: Sequence of amino acids
- Secondary: Alpha-helices and beta-pleated sheets formed by hydrogen bonding
- Tertiary: 3D structure formed by interactions among R groups
- Quaternary: Assembly of multiple polypeptide chains

Classification: Fatty acids, triglycerides, phospholipids, steroids
Functions:
- Energy storage
- Insulation and protection
- Structural components of cell membranes

Types:
- Saturated: No double bonds, solid at room temperature (e.g., butter)
- Unsaturated: One or more double bonds, liquid at room temperature (e.g., olive oil)
Roles: Energy source, hormone production, and cellular membrane structure

Monosaccharides: Simple sugars (e.g., glucose, fructose)
Disaccharides: Two monosaccharides liked (e.g., sucrose)
Polysaccharides: Long chains of monosaccharides (e.g., starch, glycogen, cellulose)
Functions: Energy source, structural components, and cell recognition

Shape: Double helix composed of two strands
Components:
- Nucleotides: Made of a sugar (deoxyribose), phosphate group, and nitrogenous base (adenine, thymine, cytosine, guanine)
Base Pairing: Adenine pairs with thymine (A-T), cytosine pairs with guanine (C-G)
Antiparallel Strands: One strand runs 5' to 3', while the other runs 3' to 5', crucial for replication and transcription