Search Results

Renin/Angiotensin (water gain from urine & Na ion and water reabsorption)

By: HWC, Views: 6538

• Sensing declining blood pressure or blood volume, juxtaglomerular cells of the nephron release renin, an enzyme that promotes the formation of angiotensin II. • Angiotensin II targets smooth muscle cells in blood vessels that provide blood to the nephron. • Angiotensin II causes thes...

Atrial natriuretic peptide (vasodilation) & Aldosterone

By: HWC, Views: 6326

• Certain situations will cause the body's stress level to rise. • increased blood pressure will stretch the atria of the heart, stimulating the secretion of atria natriuretic peptide (MP). • ANP causes muscle cells in blood vessels to relax. • Blood pressure is lowered as a result ...

Miller's reaction chamber experiment Animation

By: HWC, Views: 258

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. ...

Double Vacuum Process (Illustration No Audio)

By: HWC, Views: 5871

In this so-called low-pressure process, the wood is first subjected to a short and relatively weak initial vacuum, after which the treatment vessel is flooded with preservative solution and reduced to normal pressure The double vacuum container is loaded with timber. A partial vacuum is draw...

HIV Infection: Viral life cycle

By: HWC, Views: 6007

The series of steps that HIV follows to multiply in the body. The process begins when HIV encounters a CD4 cell. The seven steps in the HIV life cycle are: 1) binding; 2) fusion; 3) reverse transcription; 4) integration; 5) replication; 6) assembly; and 7) budding. Many viruses f...

The life cycle of protein

By: HWC, Views: 6200

The life cycle of a typical protein begins with its synthesis on a ribosome. As the polypeptide chain grows, molecules of a chaperone protein bind along its length. This prevents misfolding of the nascent polypeptide. ATP binding causes chaperone release. For most proteins, the polypeptide th...

Gas exchange - partial pressure, locations, external and internal respiration

By: HWC, Views: 6797

▪ In a mixture, each individual gas exerts a pressure that is proportional to the concentration of that gas within the mixture. • This part of the total pressure is called a "partial pressure". • A gas moves along the part of the pressure gradient determined by its own concentration. ...

Predator- prey competition and symbiosis

By: HWC, Views: 6463

Predator-prey relationships occur when one species, the predator, kills and eats an organism of another species, the prey. This graph shows the cyclical nature of predator-prey relationships, in this case among populations of Canada lynx and snowshoe rabbits. If predation is without some li...

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

By: HWC, Views: 6753

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...