Monday WEEK 4

Lysosomes and Tasex Disease

• Lysosomes: Organelles responsible for breaking down waste materials and cellular debris in cells.

• Tasex Disease: A genetic disorder resulting from lysosome malfunction, affecting lipid breakdown primarily in brain cells. It leads to the accumulation of undigested molecules, causing neurological disorders.

Peroxisomes

• Peroxisomes: Organelles with specialized functions that break down fatty acids and manage lipid metabolism. The byproduct of fatty acid breakdown is hydrogen peroxide (H₂O₂), a toxic substance.

• Catalase: An enzyme present in peroxisomes that decomposes hydrogen peroxide into water and oxygen, preventing cellular damage. Bubbles observed when hydrogen peroxide is applied to cuts are due to catalase activity.

Free Radicals

• Definition: Highly reactive molecules generated during metabolism or from external sources like radiation and pollution.

• Impact: Free radicals can damage cellular components, including DNA. This damage can cause mutations, leading to various health issues.

  • Mutations: Not all mutations are detrimental, but those altering DNA can have significant consequences.

Zellweger Syndrome

• Overview: A disorder affecting peroxisome function impacting multiple body systems.

• Cerebrohepatorenal Syndrome: Indicates the involvement of the brain (cerebro), liver (hepato), and kidneys (renal). Symptoms include malformations, liver issues, and possible neurological deficits due to fatty acid buildup.

Mitochondria

• Function: Known as the powerhouse of the cell, mitochondria are responsible for producing ATP (adenosine triphosphate) through aerobic respiration, which converts food molecules into usable energy.

• Endosymbiotic Theory: Mitochondria are believed to be derived from ancient bacteria, possessing their own DNA and ribosomes.

• Structure: Mitochondria have two membranes:

  • Outer Membrane: Encloses the organelle.

  • Inner Membrane: Folded to increase surface area; site where ATP is synthesized.

  • Intermembrane Space: The space between the inner and outer membranes.

  • Matrix: The space enclosed by the inner membrane, containing enzymes for metabolic processes.

Summary of Key Concepts

• Lysosomes: Break down waste; malfunction leads to diseases like Tasex disease.

• Peroxisomes: Manage fatty acid metabolism, produce H₂O₂; catalase protects cells from oxidative damage.

• Free Radicals: Reactive molecules causing cellular damage.

• Zellweger Syndrome: A condition resulting from dysfunctional peroxisomes.

• Mitochondria: Main site for ATP production, with a unique evolutionary origin and structural features that support its function.