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Results for: 'chemical and molecular evolution'

Immune responses Animation

By: HWC, Views: 3543

Overview of interactions in antibody-mediated and cell-mediated immunity Animation The antibody mediated immune response begins when a naive B cell encounters antigens from a pathogen, such as a bacterium. The B cell binds, processes, and displays this antigen. It is now an antigen-presenti...

Contraction and Relaxation Animation

By: Administrator, Views: 9605

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...

Introduction to Genetics

By: Administrator, Views: 9517

Genetics is a branch of biology concerned with the study of genes, genetic variation, and heredity in organisms. Gregor Mendel, a scientist and Augustinian friar, discovered genetics in the late 19th-century. Mendel studied "trait inheritance", patterns in the way traits are handed down from p...

Nervous pathway to the Neuromuscular (NMJ)

By: HWC, Views: 7189

• A nervous impulse, also called an action potential, starts from the brain or spinal cord to signal skeletal muscle cell contraction. Action potentials continue along a motor neuron to the muscle cell. • The signal to contract must cross a synapse - the neuromuscular junction (NMJ) - betwe...

Neural regulation of blood pressure - baroreceptor and chemoreceptor reflexes

By: HWC, Views: 6978

• The nervous system regulates blood pressure with two reflex arcs: baroreceptor and chemoreceptor. ■ Baroreceptors (pressure) and chemoreceptors (chemical) are located in the carotid sinus and aortic arch. • Carotid sinus reflex helps maintain normal blood pressure in brain. • Ba...

Splitting of Sugar, Oxidation/ Reduction & ATP Generation

By: HWC, Views: 6380

The next reaction shows us the meaning of "glycolysis" or the splitting of glucose. The fructose bisphosphate molecule is split into two molecules each containing 3 carbons as the backbone. FBP is split into two 3-carbon molecules called G3P, or glyceraldehyde 3-phosphate. Notice that the phos...

Hormonal feedback loop components

By: HWC, Views: 6810

The endocrine system maintains many body conditions within normal limits with feedback loops. Each endocrine feedback loop maintains homeostasis using the following components: ■ Stimulus - a change in a body condition. ■ Production cell - an endocrine cell that produces a hormone after b...

How do the different types of chromatography work? (No Audio)

By: HWC, Views: 5995

Chromatography is a term for a variety of techniques in which a mixture of dissolved components is fractionated as it moves through some type of porous matrix. A glass column is filled with beads of an inert matrix. The mixture of proteins to be purified is dissolved in a solution and passed ...

Simple and Double Sugar

By: HWC, Views: 6494

Here are the molecular structures of three simple sugars: glucose, ribose, and fructose. Look at these simple sugars and identify what characteristics they all share. As you can see, all of the carbohydrates have carbon, hydrogen, and oxygen in a ratio of 1:2:1 and there is always a double bo...

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