Molecular Medicine

The enzymes only function in the lysosome bc the pH 5 is at their optimum. They are innactive in the serum.

Posttranslational modification of lysosomal enzymes is defective in I-Cell Disease. Proteins are secreted outside the cell into the serum

Proteins are secreted outside the cell into the serum.

A number of genetic diseases lacking lysosomal enzymes result in the progressive accumulation within the cell of partially degraded insoluble products. This condition leads to clinical conditions known as lysosomal storage disorders. Can be toxic

Outer - Sphingomyelin, Phospha-tidyl-ethanol-amine, Glycolipids

Inner - Phosphatidylserine, Phosphatidylinositol, Phospha-tidy-ethanol-amine

Signaling Processes- membrane invagination

Cholesterol Uptake

Specializes in the production
or utilization of hydrogen peroxide enzymes such as D-amino acid oxidase, ureate oxidase, and catalase.

Peroxisomes are also involved in the b-oxidation of very long chain fatty acids (C18 or longer).

Basic dye, carries a net positive charge. Stains the cell nucleus and RNA-rich organelles blue/purple; in contrast

Acidic dye, carries a net negative charge. stains mitochondria, secretory grannules and extracellular material such as collagen pink

-Made up of globular g-actin formed into filamentous f-actin

-Has a plus, fast growing end (barbed), and a minus slow growing end (pointed)

-Polymerization into filaments occurs when the concentration of g-actin is above the critical concentration.

The polymerization and depolymerization of actin is a dynamic, constant process

Actin associated proteins perform several functions in arranging and stabilizing the filaments including: crosslinking, bundling, capping, severing and movement of structures along the fiber

-Largest of the major cytoskeletal components

-Made up of alpha and beta subunits which form dimers then protofilaments. 13 protofilaments form polarized tubules, alpha subunit at the minus end and beta subunit at the plus end.

-Growth is faster at the plus end.

+ away from MTOC - toward MTOC

Microtubule assembly is typically from a MTOC

In most cells these are the centrosomes

9 + 0 and in triplets
9 + 2 and in doublets

Binds to microtubules and prevents their depolymerization.. Prevents mitosis

Type I (acidic) and II (basic and neutral) cytokeratins found in epithelial cells and epithelial derivatives

Type III vimentin like.
Vimentin-cells of mesenchymal origin
Desmin skeletal muscle

Type III cont.
Glial fibrillary acidic protein- astrocytes
Peripherin- peripheral nerves

Type IV- Neurofilaments- axons and dendrites of nerves
Type V- Nucleur lamins A,B,C- inner nucleur membrane (form meshwork)
Type VI- Nestin- neuronal stem cells of CNS

-Molecular motors move organelles and other structures within a cell

-The major types are kinesins, dyneins and myosins.

-The kinesins and dyneins move along microtubules while myosin moves along actin filaments

Anterograde transport things to the periphery of cell + end

Reterograde transport things toward the cell body - end