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Results for: 'is a weak acid. • Few molecules dissociate because a strong attraction exists between H and HCO5. درجة الحموضة: ھو مقیاس لتحدید تركیز أیونات الھیدروجین H في المحلول یُرمز لدرجة الحموضة بالرمز (pH) وتُعرف أیضاً بالرقم الھیدروجیني أو الأس الهيدروجيني . درجة الحموضة مقیاس مدّرج من 0 إلى 14 ویُعبّر عن تركیز أیونات H وأیونات -OH في المحلول. فالمحالیل الحمضیة تمتلك قیمة pH أقل من (7)، وكلما قلت قیمة pH للحمض زادت قوتھ. والمحالیل القاعدیة تمتلك قیمة pH أكبر من (7)، وكلما زادت قیمة pH للقاعدة زادت قوتھا. أما الماء المقطر فتبلغ قیمة pH لھ (7)، أي أنھ یُعتبر متعادلاً وفق ھذا المقیاس لأن تركیز أیونات-OH مساٍو لتركیز أیونات H تعتمد قيمة PH للمحلول على تركيز كل من أيون الهيدروجين الموجب H وأيون الهيدروكسيد السالب OH-'

Mitochondrial Structure & ETC Protein Complexes (Protein Complexes and Electron Transport)

By: HWC, Views: 6256

The energy carrying molecules, NADH and FADH2, that were generated in glycolysis and the Krebs cycle, now are processed in the mitochondria where their high energy electrons are deposited in an electron chain complex located in the inner mitochondrial membranes. These high-energy electrons now dr...

Ventilation - phases and driving forces

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...

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...

Major Elements in Biological Molecules: Nucleic acids

By: HWC, Views: 6626

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...

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 ...

Protein Structure - Primary, Secondary, Tertiary and Quaternary

By: HWC, Views: 6657

A protein's first order structure, or primary structure, begins with the amino acid sequence of the polypeptide chain. The 20 different amino acids can be arranged in an infinite number of sequences. For example, the hormone insulin, which regulates the uptake of glucose from the blood into ce...

TRH/TSH/Thyroid hormone

By: HWC, Views: 6235

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...

The Lac Operon in E. Coli

By: Administrator, Views: 10711

The lac operon (lactose operon) is an operon required for the transport and metabolism of lactose in Escherichia coli and many other enteric bacteria. Although glucose is the preferred carbon source for most bacteria, the lac operon allows for the effective digestion of lactose when glucose is no...

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...

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