Search results for: 'Membrane transport proteins'

Watch Later 1:29

By: Administrator, Views: 12289

Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubules. These cells are called spermatogonial stem cells. T...

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Barriers - eye structures, digestive mucosa, respiratory mucosa & genitourinary mucosa

By: HWC, Views: 9176

• Eyebrows, eyelids, eyelashes and conjunctiva serve to trap microbes preventing their invasion. • Tearing (lacrimation) is a protective mechanism that washes away microbes that attempt to enter the eyes. • Salts, mucus, and lysozymes in tears neutralize substances and bacteria. �...

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Energy sources - types

By: HWC, Views: 9046

• The amount of ATP stored in a skeletal muscle cell can only provide muscular activity for two to three seconds. • Muscle cells must be able to generate additional molecules of ATP to continue contracting. • Muscle cells can generate ATP from several processes: • Phosphogen syste...

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Otitis Media

By: Administrator, Views: 12042

Otitis media is a group of inflammatory diseases of the middle ear. The two main types are acute otitis media (AOM) and otitis media with effusion (OME). AOM is an infection of rapid onset that usually presents with ear pain. In young children this may result in pulling at the ear, increased cryi...

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Enzyme structure - Properties of enzymes

By: HWC, Views: 8838

■ Enzymes are proteins that catalyze reactions. ■ Some enzymes have two parts: a protein or apoenzyme and a non-protein or cofactor. ■ Cofactor can be a metal ion or another organic molecule called a coenzyme. ■ Coenzymes often come from vitamins. ■ Cofactors affect the shape of...

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What Are Carbohydrates? Importance of Carbs & High Carb Food

By: HWC, Views: 8980

We hear a lot about carbohydrates in the news. Everybody seems to be on a low-carb diet. The news media often has stories on this diet fad, and companies are busy producing products with reduced carbohydrates. What's this fascination with carbohydrates? In a word: "Diet." The fact is that carb...

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ACTH/Cortisol (glycogenolysis, protein catabolism, lipolysis and gluconeogenesis)

By: HWC, Views: 8759

• A decline in blood glucose concentration stimulates corticotropic cells in the anterior pituitary to produce adrenocorticotropic hormone (ACTH). • ACTH binds with cells in the zona fasciculata of the adrenal cortex. • Increased ACTH promotes the production of cortisol, the major gluco...

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Glucose anabolism reactions: Glycogenolysis and Gluconeogenesis

By: HWC, Views: 9269

• Glucose not needed immediately is stored as glycogen. The process that creates it is glycogenesis. • When ATP is needed for body activities, stored glycogen is broken down by a process called glycogenolysis. • Glucose can be formed through two different anabolic reactions: • Glycog...

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Bond in biological molecules (Ionic, Covalent and Hydrogen bonds)/ How atoms bond?

By: HWC, Views: 6196

Sodium atoms and chloride atoms have unfilled orbitals in their outer shells. The lone electron in the outermost shell of a sodium atom can be pulled or knocked out. This ionizes the atom. It is now a positively charged sodium ion. A chlorine atom has an electron vacancy in its outer shell and...

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