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Role of the respiratory system - effect of altered ventilation rates

By: HWC, Views: 8754

• Dissociation of the chemical substances in the body fluids can result in the production of free hydrogen ions. • The pH scale is used to measure the concentration of hydrogen ions in solution. • Normal blood pH values vary around 7.4. • When hydrogen ion concentration increases, t...

Helper T cell receptors, activation, proliferation, differentiation & action

By: HWC, Views: 9026

• Most cells which have CD4 on their surface become Helper T cells (TN cells). • The CD4 1 cells only recognize a foreign antigen when it is presented with an antigen presenting immune cell (APC) that includes MHC-II protein. • The Helper T cell antigen receptor must match the presented...

Factors that affect conduction rates (myelination, axon diameter & temperature)

By: HWC, Views: 9010

• Several factors determine the rate of conduction of action potentials: • Myelination • Axon diameter • Temperature • The step-by-step depolarization of an axon is called continuous conduction and occurs along unmyelinated axons. • Neurons in the PNS have many axons that ...

The Lac Operon in E. Coli

By: Administrator, Views: 12996

The lac operon (lactose operon) is an operon required for the transport and metabolism of lactose in Escherichia coli and many other enteric bacteria. Although glucose is the preferred carbon source for most bacteria, the lac operon allows for the effective digestion of lactose when glucose is no...