CKS Genetic Mutations

Understanding Genes and Genetic Mutations

• Gene Definition: A segment of DNA that represents a specific genetic code, acting as a blueprint for individual biological makeup.

• DNA as Blueprint: Just like LEGO blocks form various structures, DNA sequences construct different physical attributes in organisms.

What is a Genetic Mutation?

• Definition: A genetic mutation constitutes a random alteration in the DNA sequence of an organism.

• Causes of Mutations: Can stem from external factors known as mutagens, including:

  • Smoking

  • Radiation

Types of Genetic Mutations

1. Substitution Mutations

• Concept: Substitution mutation involves replacing one nucleotide base with another.

• Example: If the fifth base in a DNA strand is swapped for cytosine.

• Visual Representation: Ability to draw original vs. mutated DNA strands.

Doodles and Descriptions for Substitution Mutations

• C G A T (Example base identification)

• Visuals: Draw the transformation of base pairs to illustrate substitution.

2. Insertion Mutations

• Concept: An insertion mutation introduces one or more nucleotides into the DNA sequence.

• Example: Inserting guanine before the fourth base.

• Visual Representation: Illustrate changes in the DNA strand length due to insertion.

3. Deletion Mutations

• Concept: A deletion mutation entails the removal of one or more nucleotides from the sequence.

• Example: Deleting the second base from a DNA strand can alter outcomes significantly.

• Visual Representation: Show how the removal affects subsequent base pair arrangement.

Effects of Mutations on Proteins

• Protein Synthesis: Mutations can lead to changes in the resulting proteins, influencing organism structure and function.

• **Types of Mutation Effects:

  • Silent Mutation: No alteration in the amino acid sequence.

  • Missense Mutation: Changes one amino acid, which can affect protein function.

  • Nonsense Mutation: Introduces a premature stop signal, potentially yielding incomplete proteins.

  • Frameshift Mutation: Alters the reading frame, impacting multiple amino acids.

The Central Dogma of Molecular Biology

• Flow of Information: DNA -> mRNA -> Protein

  • Transcription: Conversion of DNA to mRNA.

  • Translation: Process where mRNA is used to synthesize proteins.

• Codon Chart Usage: mRNA sequences read in groups of three bases (codons) dictate specific amino acids.

RNA vs. DNA Differences

• Stranded Structure:

  • DNA: Double-stranded

  • RNA: Single-stranded

• Sugar Composition:

  • DNA: Deoxyribose

  • RNA: Ribose

• Bases Present:

  • DNA contains Thymine

  • RNA contains Uracil instead of Thymine.

Biomolecules Overview

• Definition of Biomolecules: Molecules critical for biological processes, including proteins, lipids, carbohydrates, and nucleic acids.

• Key Functions of Biomolecules:

  • Proteins: Structure, enzymes

  • Carbohydrates: Immediate energy, cell structure

  • Lipids: Long-term energy storage, cellular membranes

  • Nucleic Acids: Storage and expression of genetic information.

Cell Cycle and Division

• Concept of Cell Cycle: A continuous cycle involving growth, DNA replication, and mitosis.

• Phases: G1 (growth), S (DNA synthesis), G2 (preparation for mitosis), M (mitosis).

• Mitosis: Division process yielding two identical daughter cells, crucial for growth and repair.

Cancer and Cell Division Regulation

• Cancer Description: Uncontrolled cell division that results from failures in the regulation of the cell cycle.

• Types of Tumors:

  • Benign: Non-cancerous, contained growth.

  • Malignant: Cancerous, can spread (metastasis).

• Apoptosis: Programmed cell death, crucial for maintaining cell health and preventing cancer.