Human Genetics

Cells

Great Web Sites

http://www.johnkyrk.com/ Nice animations of various cellular processes

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/A/AnimalCells.html Guide to specific organelles

http://publications.nigms.nih.gov/insidethecell/index.html Inside the Cell- comprehensive web site from

NIH

Cells are fundamental units of life

Inherited traits can be understood at both the cellular and molecular level.

At the molecular level, we can identify the gene, the mutation, and the role of the protein.

At the cellular level, we can see how the protein affects the cell and the whole organism.

Duchenne’s Muscular Dystrophy

Cystic Fibrosis

Sickle Cell Anemia

Cells are made of biomolecules

CarbohydratesLipidsProteinsNucleic AcidsVitaminsMinerals

Eukaryotic Cells are complex

Nucleus: Largest structure in cells

Nucleus is the Cell’s Brain

Nuclear membrane Double membrane

Nuclear pores Nuclear trafficking

Nucleolus RNA production

Chromosomes genetic material

Secretion: Milk Production

Cells have specialized networks to manufacture and deliver products

Rough ER is covered with ribosomes and prepares newly made proteins; smooth ER specializes in making lipids and breaking down toxic molecules.

Golgi Apparatus

The Golgi apparatus receives newly made proteins and lipids from the ER, puts the finishing touches on them, addresses them, and sends them to their final destinations.

Plasma membranes control external environment/cell communication.

Plasma membranes are a complex phospholipid bilayer supported by a layer of protein fiber supports.The membranes are studded with other lipids (like cholesterol) traveling together in rafts.They also contain proteins which act as receptors.Receptors are structures that recognize and bind ligands, setting in motion a signal transduction pathway.

Signal Transduction is important role of cell membrane components

Intracellular Digestion Eukaryotic cells break down

molecules as well as produce them.

Lysosomes break down bacteria as well as worn-out organelles by fusing their membranes and then releasing digestive enzymes.

Then they dump their contents outside the cell by fusing with the plasma membrane. Many components are also recycled within the cell for other metabolic processes.

Lysosomes: Fuse with vesicles and organelles to recycle components

Peroxisomes: filled with detoxification enzymes

Mitochondria Mitochondria have an outer membrane,

and an inner membrane. The inner membrane is four or five times larger than the outer membrane. It doubles over in many places, extending long folds into the center of the organelle.

These folds dramatically increase the surface area available to the cell machinery that makes ATP.

The mazelike space inside mitochondria is filled with hundreds of enzymes, DNA (mitochondria have their own genetic material), special mitochondrial ribosomes, and other molecules necessary to turn on mitochondrial genes.

Cytoskeleton

actin filaments appear light purple, microtubules yellow, and nuclei greenish blue.

http://publications.nigms.nih.gov/insidethecell/extras/tomogram.mov

Cytoskeleton is made of protein rods and tubules

Epidermolysis Bullosa

Abnormal intermediate filaments in the skin cause epidermolysis bullosa, a rare genetic disease. The fragile skin and recurrent blister formation, result from minor mechanical friction or trauma

Red Blood Cell Plasma Membrane

Hereditary spherocytosis is a disease caused by a defect of the ankyrin in the RBC plasma membrane. It causes the plasma membrane to collapse in the turbulent forces of the circulation and the cell to balloon out.

Apoptosis: Programmed Cell Death

Organelle Dimensions are Nanoscale

A micrometer is one millionth (10-6) of a meter. A nanometer is one billionth (10-9) of a meter.

Stem Cells offer new insights into human genetics

All cells descend from stem cells

Therapeutic use of stem cells