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Results for: 'organic substances'

Morphology of a tomato plant

By: HWC, Views: 1269

The bulk of the plant body is comprised of ground tissue. Vascular tissue threads through the ground tissue. It distributes water, solutes, and organic substances through the plant body. Dermal tissue covers and protects the surfaces of the root and shoot systems.

Enzyme structure - Properties of enzymes

By: HWC, Views: 6652

■ Enzymes are proteins that catalyze reactions. ■ Some enzymes have two parts: a protein or apoenzyme and a non-protein or cofactor. ■ Cofactor can be a metal ion or another organic molecule called a coenzyme. ■ Coenzymes often come from vitamins. ■ Cofactors affect the shape of...

Vascular tissues in a corn stem and a buttercup root

By: HWC, Views: 1196

Vascular tissues in a corn stem and a buttercup root. The cells that make up each tissue. Xylem conducts water and dissolved ions. It also helps mechanically support a plant. The cells, called vessel members and tracheids, are dead at maturity. Their lignified walls interconnect and serve as p...

Biological organic compounds

By: HWC, Views: 6111

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...

Miller's reaction chamber experiment Animation

By: HWC, Views: 317

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. ...

Endocytosis - pinocytosis, receptor mediated and Transcytosis

By: HWC, Views: 6618

Pinocytosis is the process in which a cell "drinks" a tiny droplet Of extracellular fluid, including its solutes. Pinocytosis (Cell Drinking) is the process by which the cell takes in fluids (as well as any small molecules dissolved in those fluids). • The plasma membrane folds inward to...

Mechanisms of capillary exchange (transcytosis & bulk flow)

By: HWC, Views: 6326

■ 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...

Mechanisms of capillary exchange

By: HWC, Views: 6806

■ The primary role of capillaries is to permit the exchange of nutrients and wastes between the blood and tissue cells (via interstitial fluid). ■ Oxygen and nutrients move from the blood to the cells. ■ Carbon dioxide and other wastes move from the cells to the blood. The three ba...

Types of antimicrobial substances (interferons & complement protein)

By: HWC, Views: 6764

• Found in blood and interstitial fluids. • Discourage microbial growth. • Include interferon and complement proteins. • Produced and released by virus-infected lymphocytes. • Enter new cells and inhibit viral replication. • Act against a large variety of viruses (non-speci...

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