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Segmentation and migrating motility complexes & Gastroileal reflex

By: HWC, Views: 6557

• Within a few hours, most of the stomach contents are in the duodenum. • Distension of stretch receptors in the small intestine activates a reflex that stimulates segmentation, a mixing movement. • During segmentation, sections of the intestine are constricted. • This movement incr...

Mitochondrial Structure & ETC Protein Complexes (Protein Complexes and Electron Transport)

By: HWC, Views: 6234

The energy carrying molecules, NADH and FADH2, that were generated in glycolysis and the Krebs cycle, now are processed in the mitochondria where their high energy electrons are deposited in an electron chain complex located in the inner mitochondrial membranes. These high-energy electrons now dr...

Cell mediated immune response to a viral infection Animation

By: HWC, Views: 2684

Intracellular pathogens are the targets of cell-mediated immune response. The process begins when a virus infects a macrophage. Another macrophage engulfs the same virus or an antigen from it. In both cells, enzymes cleave the viral antigens into small bits. The fragments move to the cell sur...

Complement Proteins Animation

By: HWC, Views: 3463

Formation of membrane attack complexes. Complement proteins can activate when they bind to antibodies that are bound to a pathogen. Complement proteins also activate when they bind directly to bacterial surfaces. Cascading reactions yield huge numbers of different types of complement protei...

Role of complement proteins

By: HWC, Views: 6400

• Non-specific and specific defense mechanisms work through the functions of complement proteins. • As soon as pathogens penetrate the physical barrier of the skin, other resistance mechanisms begin. • Cells, such as macrophages, phagocytize pathogens. • These cells increase exposu...

Types of antimicrobial substances (interferons & complement protein)

By: HWC, Views: 6720

• Found in blood and interstitial fluids. • Discourage microbial growth. • Include interferon and complement proteins. • Produced and released by virus-infected lymphocytes. • Enter new cells and inhibit viral replication. • Act against a large variety of viruses (non-speci...

Michaelis–Menten equation & Kinetic parameters

By: HWC, Views: 6380

The Michaelis–Menten equation is the rate equation for a one-substrate enzyme-catalyzed reaction. This equation relates the initial reaction rate (v0), the maximum reaction rate (Vmax), and the initial substrate concentration [S] through the Michaelis constant KM—a measure of the substrat...

ETC Protein Complexes & Chemiosmosis (Total ATP Production and ATP Synthase)

By: HWC, Views: 6341

You will notice that FADH2 donates two electrons further downstream than NADH. This results in only two protons being pumped across the inner membrane. The final electron acceptor for these transported electrons is oxygen. Oxygen receives these electrons, plus protons from the aqueous matrix. ...

Pores and Ion Channels

By: HWC, Views: 5877

Transmembrane channels, also called membrane channels, are pores within a lipid bilayer. The channels can be formed by protein complexes that run across the membrane or by peptides. They may cross the cell membrane, connecting the cytosol, or cytoplasm, to the extracellular matrix. Membrane po...