Search results for: 'pepsin molecules'

Watch Later 2:09

By: HWC, Views: 6655

Respiration is the exchange of gases between the atmosphere, blood, and cells The combination of 3 processes is required for respiration to occur Ventilation (breathing) External (pulmonary) respiration Internal (tissue) respiration The cardiovascular system assists the respiratory system b...

Watch Later 2:46

Endocytosis - pinocytosis, receptor mediated and Transcytosis

By: HWC, Views: 6591

Pinocytosis is the process in which a cell "drinks" a tiny droplet Of extracellular fluid, including its solutes. Pinocytosis (Cell Drinking) is the process by which the cell takes in fluids (as well as any small molecules dissolved in those fluids). • The plasma membrane folds inward to...

Watch Later 1:50

Major Elements in Biological Molecules: Nucleic acids

By: HWC, Views: 6627

DNA and RNA are nucleic acids (polymers of nucleotides). Two polymers with complementary nucleotide sequences can pair with each other. This pairing endows nucleic acids with the ability to store, transmit, and retrieve genetic information. Two strands of DNA pair by hydrogen bonding. A compon...

Watch Later 2:58

Cellular defenses (natural killer cells, phagocyte types & process of phagocytosis)

By: HWC, Views: 6510

• Lymphocytes that rapidly defend against abnormal (cancer) or virus-infected cells. • Found in blood, spleen, lymph nodes, and red bone marrow. • Lack receptors for binding with specific antigens. • Act upon cells displaying abnormal MHC antigens. • NK cells destroy cells in ...

Watch Later 2:11

Hemoglobin's affinity with oxygen - carbon dioxide, temperature and bisphosphoglycerate (BPG)

By: HWC, Views: 6801

• The carbon dioxide gas is temporarily converted to carbonic acid in red blood cells by the enzyme carbonic anhydrase, and then further converted to hydrogen and bicarbonate ions. • The result of increased carbon dioxide is decreased pH causing the Bohr effect. • Elevated carbon dioxid...

Watch Later 2:00

TRH/TSH/Thyroid hormone

By: HWC, Views: 6236

Thyroid hormone production • A decline in metabolic rate caused by increased metabolic need or physical exertion stimulates the production of thyrotropin hormone releasing (TRH) hormone from the cells of the hypothalamus. • Thyrotropin hormone releasing hormone targets the thyrotrophic ce...

Watch Later 2:16

Enzyme structure - Properties of enzymes

By: HWC, Views: 6615

■ 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...

Watch Later 3:15

Simple and Double Sugar

By: HWC, Views: 6493

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...

Watch Later 2:54

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

By: HWC, Views: 6834

▪ 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. ...

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