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Protein Structure - Primary, Secondary, Tertiary and Quaternary

By: HWC, Views: 6636

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: 6249

• 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: 269

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. ...

Glucagon (glycogenolysis and gluconeogenesis)

By: HWC, Views: 6517

• 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...

Glucose anabolism reactions: Glycogenolysis and Gluconeogenesis

By: HWC, Views: 6995

• Glucose not needed immediately is stored as glycogen. The process that creates it is glycogenesis. • When ATP is needed for body activities, stored glycogen is broken down by a process called glycogenolysis. • Glucose can be formed through two different anabolic reactions: • Glycog...

Mutations and translation

By: HWC, Views: 3190

A mutation, which may arise during replication and/or recombination, is a permanent change in the nucleotide sequence of DNA. Damaged DNA can be mutated either by substitution, deletion or insertion of base pairs. Mutations, for the most part, are harmless except when they lead to cell death or t...

What are Taste Receptors? How Does it Work? Animation

By: HWC, Views: 3490

Do you ever wonder how you can taste the foods you eat? It all starts with taste receptors in your muscular tongue. Taste receptor neurons are found in your taste buds but you are not looking at the taste buds. The raised bumps on the surface of the tongue that you see are specialized epith...

Molecules, Membrane Permeability and Structure

By: HWC, Views: 6143

Organisms are not isolated system at equilibrium and need to intake nutrients and electrolytes as remove wastes. Similarly Cells within an organism must also exchange compound by passing them through membrane. The permeability of a membrane is the rate of passive diffusion of molecules th...

Lipid catabolism ( ketogenesis and oxidation of glycerol) and Lipid anabolism (lipogenesis)

By: HWC, Views: 6983

• During excessive beta oxidation, the two-carbon fatty acid fragments are converted into acidic ketone bodies. • Ketosis, the overproduction of ketone bodies, can lead to acidosis (ketoacidosis) of the blood. • After lipolysis, glycerol is converted to pyruvic acid. • Pyruvic aci...