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Pores and Ion Channels

By: HWC, Views: 8020

Transmembrane channels, also called membrane channels, are pores within a lipid bilayer. The channels can be formed by protein complexes that run across the membrane or by peptides. They may cross the cell membrane, connecting the cytosol, or cytoplasm, to the extracellular matrix. Membrane po...

Protein Structure - Primary, Secondary, Tertiary and Quaternary

By: HWC, Views: 8822

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...

Polysaccharides

By: HWC, Views: 8539

More complex sugars are called polysaccharides (from "poly" meaning "many" and "saccharum" meaning "sugar"). Many things in nature are made of polysaccharides. Here we show one of the polysaccharides in corn, another in wood, and another in the exoskeletons of insects like grasshoppers. How are a...

Studying the Left and Right Brain Independently

By: Administrator, Views: 12146

A seizure, technically known as an epileptic seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with loss of consciousness (tonic-clonic seizure), to shakin...

Conduction of action potentials

By: HWC, Views: 9073

• Action potentials must be rapidly conducted over long distances in order for the nervous system to communicate with other cells. • Propagation of an action potential uses processes similar to those that generate the potential at the trigger zone. • a When a graded potential reaches ...

Contraction and Relaxation Animation

By: Administrator, Views: 11825

Muscles are responsible for movement. The types of movement are: - Locomotion, when chemical energy is changed into mechanical energy. - Propulsion of substances through tubes, as in circulation and digestion. - Changes in the sizes of openings, as in the contraction and relaxation of the iris...

Carbon fixing adaptations Animation

By: HWC, Views: 3028

Different plants trap carbon by different pathways. Most C3 plants evolved in moist, temperate zones. On hot dry days they close their stomata to conserve water and oxygen accumulates. Under these circumstances, the enzyme rubisco uses oxygen in an inefficient reaction that competes with t...

Acid-base imbalances - respiratory acidosis and alkalosis

By: HWC, Views: 9128

• The individual mechanisms involved in regulating pH work in concert with each other to ensure that blood pH is maintained within the normal range. • The two categories of pH imbalance are: • Respiratory • Metabolic • Both types of imbalances can cause either acidosis or alka...

Mechanics of Sound Animation

By: Administrator, Views: 12122

Process of Hearing Sound waves are directed to the eardrum, causing it to vibrate. These vibrations move the three small bones of the middle ear (malleus, incus, and stapes). Movement of stapes at oval window sets up pressure waves in the perilymph and endolymph. Process of Hearing The wav...