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Facilitated Diffusion - Glucose transport

By: HWC, Views: 8005

Transmembrane proteins help solutes that are too polar or too highly charged move through the lipid bilayer The processes involved are: Channel mediated facilitated diffusion Carrier mediated facilitated diffusion In facilitated diffusion, molecules only move with the aid of a protein i...

Mechanisms for chromosome movement Animation

By: HWC, Views: 4726

At mitotic metaphase, the fully-formed spindle is composed of many microtubules that extend from the poles. Some of these, the kinetochore microtubules, are attached to the kinetochores of each chromosome. Kinetochores are located at the centromeres. At anaphase, sister chromatids separate and...

Male Reproductive System - Testosterone

By: HWC, Views: 8330

• Under the influence of FSH and testosterone, Sertoli cells produce androgen-binding protein (ABP) that binds to testosterone and maintains high levels of the hormone near spermatogenic cells. • Testosterone stimulates the final stages of spermatogenesis. • In addition, testosterone is...

Gastrin (gastric emptying) & Secretin (buffering gastric acid)

By: HWC, Views: 7242

• Gastrin also binds to the smooth muscle cells in the stomach causing: • Increased gastric motility. • Opening of pyloric sphincter. • Increased gastric emptying. • The intestinal phase of digestion begins as chyme enters the duodenum. • The chyme's acidity can damage int...

Structure of Amino Acid, Peptide Bonds & Polypeptides

By: HWC, Views: 7203

Here are the molecular formulas of three different amino acids. All amino acids share this backbone. The main difference between every amino acid is the side groups seen here, and these side groups give each of the amino acids their different characteristics. But before we get into that, let's ...

Chemical Buffers - protein buffer, phosphate buffer system and bicarbonate buffer system

By: HWC, Views: 7946

• There are a variety of chemicals in body fluids that prevent the fluids from undergoing large changes in. • These chemicals buffer or regulate fluctuations in H+ concentration. • Chemical buffers: • Bind to H+ ions when there are too many in a solution so pH remains normal. •...

Cortisol (protein catabolism, gluconeogenesis, vasoconstriction & anti-inflammation)

By: HWC, Views: 7303

• Stressors stimulate production of hypothalamic releasing hormones, corticotropin releasing hormone, hormone (CRH) and adrenocorticotropic hormone (ACTH) stimulate. • These hormones promote increased production of 1 cortisol from the zona fasciculata cells of the adrenal cortex. • Cort...

Exocytosis - secretion

By: HWC, Views: 7742

Exocytosis is another method of vesicular transport that moves large volumes Of fluid or chemicals out of the cell. It is a process by which a cell transports secretory products through the cytoplasm to the plasma membrane. A examples of cellular secretory products: 1. Secreted protein - enzym...

Segmentation and migrating motility complexes & Gastroileal reflex

By: HWC, Views: 7660

• Within a few hours, most of the stomach contents are in the duodenum. • Distension of stretch receptors in the small intestine activates a reflex that stimulates segmentation, a mixing movement. • During segmentation, sections of the intestine are constricted. • This movement incr...