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DNA Replication Factory and Protein

By: HWC, Views: 7231

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...

Nucleic acid digestion -small intestine

By: HWC, Views: 7750

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...

Nucleic acid digestion - brush border enzymes, end products & transport mechanism

By: HWC, Views: 7507

• Further digestion occurs at the microvilli (brush border) of the epithelial cells of the villi in the small intestine. • Two brush border enzymes complete nucleic acid digestion: • Phosphatases, which catalyze the cleavage of a phosphate to form a nucleoside (nitrogenous base and pent...

DNA close up Animation

By: HWC, Views: 1650

A section from a DNA double helix The backbone of each DNA strand consists of alternating deoxyribose sugars and phosphate groups. The two strands run in opposite directions. One runs from the 5' to 3' direction, the other in the 3' to 5' direction. Think of the deoxyribose units o...

Major Elements in Biological Molecules: Nucleic acids

By: HWC, Views: 7629

DNA and RNA are nucleic acids (polymers of nucleotides). Two polymers with complementary nucleotide sequences can pair with each other. This pairing endows nucleic acids with the ability to store, transmit, and retrieve genetic information. Two strands of DNA pair by hydrogen bonding. A compon...

Double Stranded DNA Molecule Animation

By: HWC, Views: 5557

Double Stranded DNA Molecule Animation

Genetic distance between human groups

By: HWC, Views: 4574

One proposed family tree for modern humans. This family tree is based on nucleic-add hybridization studies of many genes and immuno-logical comparisons. Branch points show presumed genetic divergences. This data indicates that the greatest genetic distance separates humans native to Afri...

Bond types - Atomic structure and basis of bonds

By: HWC, Views: 8095

• 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 ...

Muscle Fatigue and Recovery

By: HWC, Views: 7496

• After prolonged activity, muscle contraction weakens, and the muscle enters a state of fatigue. • Fatigue results from in muscle cells, such as: • Inadequate release of calcium ions • Depletion of energy sources • Lack of oxygen • Build up of lactic acid other metabolic w...