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Protein digestion - stomach & small intestine

By: HWC, Views: 7193

• Protein digestion occurs in the stomach and small intestine. • The stomach enzyme pepsin initiates the process. • Pancreatic and intestinal brush border enzymes complete the digestive process. • In the stomach, pepsin is created from pepsinogen in the presence of pH-lowering hyd...

Major Elements in Biological Molecules: Proteins

By: HWC, Views: 7139

Proteins are chains of amino acids linked by peptide bonds. The 20 different amino acids used to make all proteins differ only in their side chains, and the properties of these side chains account for the great diversity of protein structure and function. Collagen is an example of how a prote...

Energy sources - types

By: HWC, Views: 7905

• The amount of ATP stored in a skeletal muscle cell can only provide muscular activity for two to three seconds. • Muscle cells must be able to generate additional molecules of ATP to continue contracting. • Muscle cells can generate ATP from several processes: • Phosphogen syste...

Mechanisms of capillary exchange

By: HWC, Views: 7876

■ The primary role of capillaries is to permit the exchange of nutrients and wastes between the blood and tissue cells (via interstitial fluid). ■ Oxygen and nutrients move from the blood to the cells. ■ Carbon dioxide and other wastes move from the cells to the blood. The three ba...

Proteins

By: HWC, Views: 6770

Living things must accomplish a great number of tasks just to get through a day, and these tasks are accomplished by a diverse range of biological molecules. In the range of tasks that molecules accomplish, however, proteins reign supreme. Almost every chemical reaction that takes place in living...

Electromagnetic Spectrum, Chlorophyll and Pigment & Light

By: HWC, Views: 7497

The sun gives off radiation that is called the electromagnetic spectrum. This is energy that travels as wavelengths and includes radio waves, X-rays and ultraviolet light. A portion of this radiation is known as visible light, and is the type of radiation that plants use to manufacture sugars. ...

Protein catabolism - deamination

By: HWC, Views: 7879

• Digestion hydrolyzes proteins into amino acids, which are transported to the bloodstream. • Amino acids and proteins are not stored. • Instead, they are: • Oxidized to generate ATP. • Used to synthesize new proteins. • Converted to carbohydrates or lipids for storage (if e...

Segmentation and migrating motility complexes & Gastroileal reflex

By: HWC, Views: 7660

• 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...

Bond types - Atomic structure and basis of bonds

By: HWC, Views: 8099

• Chemical bonds are fundamental to the structure and function of many types of molecules, such as proteins, carbohydrates, lipids, nucleic acids, gases, salts and water. ■ These molecules are composed of atoms that are held together by three different types of bonds. • The three types ...