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Primary Active Transport - electrochemical gradient and ion transport / water movement

By: HWC, Views: 7852

Energy derived from ATP changes the shape of a transporter protein which pumps a substance across a plasma membrane against its concentration gradient An electrochemical gradient is a gradient of electrochemical potential, usually for an ion that can move across a membrane. The gradient consis...

Fermentation - When Oxygen Is Absent, Pyruvate to Lactate & Pyruvate to Ethanol

By: HWC, Views: 7298

Pyruvate is the end product of glycolysis. If oxygen is present, pyruvate enters the mitochondrion where further energy yielding reactions of the Krebs cycle will take place. However, if oxygen is not present, pyruvate will enter a pathway called fermentation. This pathway regenerates NAD+ fro...

Control of ventilation rate by other brain centers (posts, hypothalamus & cerebral cortex)

By: HWC, Views: 7680

Forced ventilation: • The inspiratory area stimulates accessory inspiratory muscles. • Inspiration is more forceful. • Inspiratory area activates expiratory area, which sends impulses to the expiratory muscles (internal intercostals and abdominal muscles). • Expiration muscles c...

Evolutionary tree of life Animation

By: HWC, Views: 1396

An evolutionary tree of life that reflects mainstream thinking about the connections among major lineages (bya = billions of years ago, mya = millions of years ago). By about 3.8 billion years ago, chemical and molecular evolution had produced the first living cells. The first major divergenc...

Pressure volume relationships - Normal inspiration and expiration

By: HWC, Views: 7647

• Changing the relative pressure in the compartments can control the direction of airflow between compartments. • In a closed compartment, pressure and volume are inversely related. • Reducing the volume will increase the pressure. • Increasing the volume will decrease the pressure. ...

ribosome

By: HWC, Views: 7480

The trp operon in E. coli contains five structural genes corresponding to enzymes that convert chorismate into tryptophan. The trpE gene contains a 5' untranslated region that plays an important role in the regulatory mechanism called attenuation. The 5' UTR contains four regions. Region 1 en...

Proteins

By: HWC, Views: 6787

Living things must accomplish a great number of tasks just to get through a day, and these tasks are accomplished by a diverse range of biological molecules. In the range of tasks that molecules accomplish, however, proteins reign supreme. Almost every chemical reaction that takes place in living...

Methods of carbon dioxide transport - carbaminohemoglobin and bicarbonate ions

By: HWC, Views: 7793

• Carbon dioxide is transported three ways: • As bicarbonate ions in the plasma. • Bound to hemoglobin. • As a dissolved gas in the plasma. • A small percent of carbon dioxide is transported as a dissolved gas. • Some of the carbon dioxide is bound to hemoglobin, in the fo...

Electromagnetic Spectrum, Chlorophyll and Pigment & Light

By: HWC, Views: 7515

The sun gives off radiation that is called the electromagnetic spectrum. This is energy that travels as wavelengths and includes radio waves, X-rays and ultraviolet light. A portion of this radiation is known as visible light, and is the type of radiation that plants use to manufacture sugars. ...