Search Results

Digestive chemicals - types & enzymes

By: HWC, Views: 6632

• Chemical digestion breaks down food as it moves through the digestive tract. • Using enzymes and other digestive chemicals, the process reduces food particles into nutrient molecules that can be absorbed. • Most chemical digestion is done by the actions of digestive enzymes. • O...

Morphology of a tomato plant

By: HWC, Views: 1248

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.

Anatomy and Chemical Makeup of a Single Hair (Animation)

By: HWC, Views: 4938

The hair's outer cuticle surrounds hair cells filled with tough keratin macrofibrils. Each macrofibril consists of smaller microfibrils. A microfibril is made up of three keratin polypeptide chains. The chains are linked together by disulfide bonds. A hair consists of keratin chains held...

Endocytosis - pinocytosis, receptor mediated and Transcytosis

By: HWC, Views: 6591

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...

Chemical Synapse Animation

By: HWC, Views: 4021

A neuromuscular junction is a chemical synapse between the axon endings of a motor neuron and a muscle cell. A narrow synaptic cleft separates the presynaptic cell (the motor neuron) from the postsynaptic cell (the muscle cell). The presynaptic cell contains vesicles filled with neurotransmitt...

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...

Mechanisms of capillary exchange (transcytosis & bulk flow)

By: HWC, Views: 6305

■ 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: 6780

■ 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: 6740

• 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...