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Major Elements in Biological Molecules: Nucleic acids

By: HWC, Views: 6621

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...

ribosome

By: HWC, Views: 6331

The trp operon in E. coli contains five structural genes corresponding to enzymes that convert chorismate into tryptophan. The trpE gene contains a 5' untranslated region that plays an important role in the regulatory mechanism called attenuation. The 5' UTR contains four regions. Region 1 en...

ACTH/Cortisol (glycogenolysis, protein catabolism, lipolysis and gluconeogenesis)

By: HWC, Views: 6520

• A decline in blood glucose concentration stimulates corticotropic cells in the anterior pituitary to produce adrenocorticotropic hormone (ACTH). • ACTH binds with cells in the zona fasciculata of the adrenal cortex. • Increased ACTH promotes the production of cortisol, the major gluco...

Protein Structure - Primary, Secondary, Tertiary and Quaternary

By: HWC, Views: 6655

A protein's first order structure, or primary structure, begins with the amino acid sequence of the polypeptide chain. The 20 different amino acids can be arranged in an infinite number of sequences. For example, the hormone insulin, which regulates the uptake of glucose from the blood into ce...

Cortisol (protein catabolism, gluconeogenesis, vasoconstriction & anti-inflammation)

By: HWC, Views: 6265

• Stressors stimulate production of hypothalamic releasing hormones, corticotropin releasing hormone, hormone (CRH) and adrenocorticotropic hormone (ACTH) stimulate. • These hormones promote increased production of 1 cortisol from the zona fasciculata cells of the adrenal cortex. • Cort...

Miller's reaction chamber experiment Animation

By: HWC, Views: 286

A simple diagram of Stanley Miller and Harold Urey's experimental apparatus. The lower portion of the apparatus was filled with water. The upper portion was filled with a mixture of gases that simulated the earth's early atmosphere. Examples are methane, ammonia, hydrogen and carbon dioxide. ...

Cerebral Cortex Animation

By: Administrator, Views: 9986

The cerebral cortex (plural cortices), also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain, in humans and other mammals. It is separated into two cortices, by the longitudinal fissure that divides the cerebrum into the left and right cerebral hemisp...

Muscular System Animation

By: Administrator, Views: 9580

Three basic types of muscles: - Skeletal - Smooth - Cardiac Composed of striated or smooth muscle tissue and classified according to their functions and appearance. Skeletal Muscle: - Also known as voluntary or striated muscle. - Controlled by the conscious part of the brain and attach...

Glucagon (glycogenolysis and gluconeogenesis)

By: HWC, Views: 6529

• Exercise, or not having eaten recently, causes a decline in blood glucose concentration. • Low blood glucose stimulates alpha cells in the pancreatic islets to secrete glucagon. • Glucagon targets liver cells. • Glucagon causes liver cells to undergo: • Glycogenolysis, a proce...