Search results for: 'water reabsorption'

Watch Later 0:53

By: HWC, Views: 7114

Biological organic compounds contain covalent bonds, mainly C-C and C-H bonds, but also both C and H bonded to such other atoms as O and N. Some of these covalent bonds are nonpolar. Others are polar, either because one atom in the group "hogs" electrons away from other atoms in the group, or...

Watch Later 2:31

The Pressure Flow Model in a Plant

By: HWC, Views: 7103

The vascular system of plants has two transport tissues, called xylem and phloem. Xylem transports water and minerals, while phloem transports a variety of dissolved substances, including sugars and amino acids, throughout the plant. Water in the xylem always moves up, in the direction from th...

Watch Later 1:43

Digestive chemicals - water, gastric acid, bile & bicarbonate

By: HWC, Views: 7433

• Water is the most abundant molecule in ingested fluids. • Water plays a primary role in hydrolytic digestive reactions. • Helps liquefy and transport digestive foodstuffs down the tract. • Transports secretions from accessory digestive organs to gastrointestinal tract. • Aids ...

Watch Later 1:46

Mechanisms of capillary exchange (transcytosis & bulk flow)

By: HWC, Views: 7399

■ This method of capillary exchange is mainly used to transport small amounts of large, lipid-insoluble (water soluble) molecules, such as large proteins. ■ Substances, packaged in vesicles, move through endothelial cells via endocytosis and exocytosis. ■ This method of exchange is th...

Watch Later 1:27

Hydrogen bonds - role in the body

By: HWC, Views: 8013

A hydrogen bond is the electromagnetic attraction between polar molecules in which hydrogen is bound to a larger atom, such as oxygen or nitrogen. This is not a sharing of electrons, as in a covalent bond. Instead, this is an attraction between the positive and negative poles of charged atoms. ...

Watch Later 1:20

Miller's reaction chamber experiment Animation

By: HWC, Views: 1301

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. ...

Watch Later 1:25

Peptide Bond Formation Animation

By: HWC, Views: 1545

During protein synthesis, peptide bonds link amino acids together in the order specified by DNA instructions. In this case, the first two amino acids in the protein are methionine and alanine. Here are ball-and-stick models of these amino acids. Peptide bond formation is a type of condensatio...

Watch Later 0:52

Condensation and Hydrolysis Animation

By: HWC, Views: 1559

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...

Watch Later 0:37

Photosynthesis overview Animation

By: HWC, Views: 1786

Illustration of the interrelationships of the light-dependent and light-independent reactions of photosynthesis. The light-dependent reactions split water, and produce ATP and NADPH. Oxygen is a by-product of these reactions. ATP and NADPH, together with carbon dioxide, are reactants in ...

Search Results