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The pH scale - Strong acids and Weak acids

By: HWC, Views: 7763

The pH scale • Expresses concentration of H+. • range: 0-14. • 7 is neutral. • Less 7 is acid. • greater 7 is basic (alkaline). Strong acids - role in the body ■ In strong acids all molecules dissociate. ■ HC1 is highly acidic and found only in the stomach. • H...

Chemical Buffers - protein buffer, phosphate buffer system and bicarbonate buffer system

By: HWC, Views: 7945

• There are a variety of chemicals in body fluids that prevent the fluids from undergoing large changes in. • These chemicals buffer or regulate fluctuations in H+ concentration. • Chemical buffers: • Bind to H+ ions when there are too many in a solution so pH remains normal. •...

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...

Transcription—A molecular view

By: HWC, Views: 3312

Transcription, as related to genomics, is the process of making an RNA copy of a gene's DNA sequence. This copy, called messenger RNA (mRNA), carries the gene's protein information encoded in DNA. During transcription, a DNA molecule is copied into RNA molecules that are then used to translate...

Major Elements in Biological Molecules: Proteins

By: HWC, Views: 7138

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...

Gastrin (gastric emptying) & Secretin (buffering gastric acid)

By: HWC, Views: 7242

• Gastrin also binds to the smooth muscle cells in the stomach causing: • Increased gastric motility. • Opening of pyloric sphincter. • Increased gastric emptying. • The intestinal phase of digestion begins as chyme enters the duodenum. • The chyme's acidity can damage int...

DNA Replication Factory and Protein

By: HWC, Views: 7232

DNA (deoxyribose nucleic acid) carries all the genetic information needed to re-create itself and to pass on the characteristics of the organism. The “factory” model of DNA replication hypothesizes a specific nuclear structure in which the molecular machinery for replication forks are brou...

Digestive chemicals - types & enzymes

By: HWC, Views: 7706

• Chemical digestion breaks down food as it moves through the digestive tract. • Using enzymes and other digestive chemicals, the process reduces food particles into nutrient molecules that can be absorbed. • Most chemical digestion is done by the actions of digestive enzymes. • O...

Secondary and tertiary levels of protein structure Animation

By: HWC, Views: 1634

Amino acid sequence dictates a protein's final shape. The presence of certain amino acids favors a pattern of hydrogen bonding that causes part of the polypeptide chain to coil and twist into an alpha helix. The presence of other amino acids enables hydrogen bonding between strand like re...