CKS Genetic Mutations: Unit Overview

• Focus on genetic mutations, their types, and implications on proteins

Understanding Genes and DNA

• Gene: A segment of DNA, the genetic code (blueprint of the body).

• DNA Structure: Similar to LEGO blocks; determines body structure and function.

What is a Genetic Mutation?

• Definition: A random change in the DNA sequence (nucleotide order).

• Causes: Mutagens (e.g., smoking, radiation).

Types of Genetic Mutations

• Substitution: One base is exchanged for another.

• Insertion: Extra base(s) are added into the DNA sequence.

• Deletion: One or more bases are removed from the sequence.

Detailed Mutation Examples

Substitution Mutations

• Overview: One nucleotide replaces another, altering the DNA sequence:

  • Example: Original sequence changes from TAC to TAC -> C substituted for A resulting in the new sequence.

Insertion Mutations

• Overview: Inserting one or more nucleotides into a sequence:

  • Example: Adding guanine before a specific base yields a new sequence.

Deletion Mutations

• Overview: Removing nucleotides from the sequence:

  • Example: Deleting a base like G early in the sequence alters the overall coding for proteins.

Effects of Mutations on Proteins

• Changes in mutation can lead to modifications in the resultant proteins:

  • Some mutations may be silent (no effect on amino acids), missense (leading to a change in one amino acid), or nonsense (early STOP codon).

Categories of Mutations

• Silent Mutation: No change in the resulting amino acid.

• Missense Mutation: Alters one amino acid in the protein sequence.

• Nonsense Mutation: Introduces a premature STOP codon, truncating the protein.

• Frameshift Mutation: Causes the reading frame of the codons to shift, affecting several subsequent amino acids.

Implications of Genetic Mutations

• Beneficial Mutations: Can enhance survival (e.g., camouflage in animals).

• Negative Mutations: May lead to diseases or genetic disorders (e.g., sickle cell anemia).

• Neutral Mutations: No significant effect on organism's fitness.

The Central Dogma: DNA, RNA, and Protein Synthesis

• Process Overview: DNA transcribes into mRNA, which is translated into proteins.

  • Transcription: DNA to mRNA.

  • Translation: mRNA to protein at the ribosome.

• Importance of DNA bases and mutations in affecting the resulting polypeptides.

DNA and RNA Comparison

• DNA: Double-stranded, contains thymine, deoxyribose sugar.

• RNA: Single-stranded, contains uracil, ribose sugar.

Cellular Processes and Transport

• Homeostasis at the cellular level is maintained by cell membranes:

  • Selective Permeability: Controls what enters and exits the cell.

• Types of transport: Passive transport (no energy) and active transport (requires ATP).

Review of Cell Types

• Prokaryotic Cells: No nucleus, smaller, simpler structure.

• Eukaryotic Cells: Have a nucleus, larger, complex structures with specialized organelles.

Basic Cell Theory

• All living things consist of cells, which are the fundamental unit of life.

• Cells arise from pre-existing cells.

Biomolecule Overview: Key Components

• Biomolecules: Include carbohydrates, lipids, proteins, and nucleic acids (RNA/DNA).

• Each has unique functions essential for life processes.

Final Thoughts

• Understanding genetic mutations is crucial for comprehending molecular biology, genetics, and their implications on health and disease.