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Fermentation - When Oxygen Is Absent, Pyruvate to Lactate & Pyruvate to Ethanol

By: HWC, Views: 6184

Pyruvate is the end product of glycolysis. If oxygen is present, pyruvate enters the mitochondrion where further energy yielding reactions of the Krebs cycle will take place. However, if oxygen is not present, pyruvate will enter a pathway called fermentation. This pathway regenerates NAD+ fro...

Fermentation pathways

By: HWC, Views: 626

Both lactate fermentation and alcoholic fermentation begin with pyruvate formed by glycolysis. During lactate fermentation, pyruvate molecules accept electrons and hydrogen from NADH. This transfer regenerates NAD± and converts pyruvate to lactate. The net energy yield is the two ATP...

Proteins Defined, Hierarchy & Composition of Cells

By: HWC, Views: 6148

Proteins are long chains of amino acids linked together by peptide bonds. Together with the other three biological macromolecules—carbohydrates, lipids, and nucleic acids—proteins are the building blocks of cells. Proteins are the most complex and abundant biological macromolecules in cel...

Protein digestion - stomach & small intestine

By: HWC, Views: 6082

• 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...

The pH scale - Strong acids and Weak acids

By: HWC, Views: 6710

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...

Nucleic acid digestion -small intestine

By: HWC, Views: 6731

Nucleic acid digestion, which takes place in the small intestine, involves: • Pancreatic nucleases. • Brush-border enzymes in the small intestine. • Nucleic acids enter the small intestine dissolved in gastric chyme. • As gastric chyme enters the duodenum of the small intestine, p...

Lipid digestion - mouth, stomach and small intestine

By: HWC, Views: 6749

• Lipid digestion takes place primarily in the small intestine; some occurs in the mouth and stomach. • Lipases are enzymes that break down triglycerides and phospholipids. • Lingual and gastric lipases hydrolyze a small amount of triglycerides. • End products are fatty acids and...

Carbohydrate digestion - mouth and stomach & pancreas and small intestine

By: HWC, Views: 6412

• Digestion of complex carbohydrates (starches and glycogen) involves: • Amylases produced by the salivary glands and pancreas. • Brush-border enzymes in small intestine. • In the mouth, amylase from the parotid and submandibular salivary glands begins carbohydrate digestion. â€...

Acids and bases - definition

By: HWC, Views: 6590

Acids and bases are found all around your house. For example, if you open your pantry or refrigerator, you might see a lot of acids. Fruit juice, soda pop, vinegar, and milk are all examples of acids. The word acid actually comes from a Latin term meaning ''sour.'' Many materials, like sugar for ...