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Molecules, Membrane Permeability and Structure

By: HWC, Views: 6168

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...

Glycolysis Animation

By: HWC, Views: 600

In glycolysis, a six-carbon glucose molecule is split into two three-carbon pyruvate molecules. In this animation, each carbon molecule is represented by a red ball. The end products of glycolysis are two molecules of pyruvate. Glycolysis is the breakdown of glucose into two molecules of ...

Resting membrane potential - electrical polarity and maintenance requirements

By: HWC, Views: 6465

• A resting membrane potential exists when there is a buildup of: 1. positive ions outside the membrane. 2. negative ions inside the membrane. • Membranes with opposing charges are said to be polarized. • The difference in charge applies only to the small distance across the membran...

Import of Dietary Glucose from Intestines to Bloodstream

By: HWC, Views: 6120

• Membranes have hydrophobic interiors. which resist the passage of hydrophilic compounds and ions. • However. transporter membrane proteins facilitate the passage of these molecules. • Passive transporters accelerate diffusion of molecules towards equilibrium (decrease a concentrat...

Proteins Defined, Hierarchy & Composition of Cells

By: HWC, Views: 6164

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...

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

By: HWC, Views: 6223

• 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...

Condensation and Hydrolysis Animation

By: HWC, Views: 544

A condensation reaction joins two molecules together to form one larger molecule. An enzyme removes a hydroxyl group from one molecule and a hydrogen atom from another, then speeds the formation of a bond between the two molecules at their exposed sites. Typically the discarded atoms join t...

DNA Replication Factory and Protein

By: HWC, Views: 6149

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...

What are Taste Receptors? How Does it Work? Animation

By: HWC, Views: 3505

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...