How rainwater forms bicarbonate and carbonate Dissolving (CO2): When rainwater falls, it absorbs carbon dioxide from the atmosphere.

Forming carbonic acid: This dissolved (CO2) reacts with water to create unstable carbonic acid.

Dissociating into ions: The carbonic acid then releases hydrogen ions, forming bicarbonate ions.

Further dissociation: If the solution becomes more alkaline (higher pH), the bicarbonate can lose another hydrogen ion to form carbonate ions. The role of water's chemistry

Citric Acid Alkalizing Effect

In general chemistry: Citric acid is a weak organic acid and lowers the pH of a solution by releasing hydrogen ions (H+). It is used to reduce water alkalinity in industrial and agricultural settings.

In the body: When consumed, the citrate from the metabolism of citric acid is thought to have an alkalizing effect on bodily fluids like urine by increasing its pH and enhancing the solubility of substances like uric acid, which helps prevent kidney stones.

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how does the body convert monocarboxylic into tricarboxylic?

The body converts monocarboxylic acids into tricarboxylic acids by breaking down the monocarboxylic acids into a two-carbon molecule called acetyl-CoA, which then enters the Tricarboxylic Acid (TCA) cycle and combines with the four-carbon molecule oxaloacetate to form the six-carbon tricarboxylic acid, citrate.

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Sodium bicarbonate breaks the hydrogen bonds in citric acid by neutralizing it through an acid-base reaction, which displaces the hydrogen ions from the citric acid molecules. This reaction, which occurs when water is added, causes the formation of carbonic acid (𝐻2𝐶𝑂3), which is unstable and quickly decomposes into carbon dioxide gas (𝐶𝑂2) and water (𝐻2𝑂), creating the fizzing effect.

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Medical: A combination of tartaric acid, sodium citrate, sodium bicarbonate, and citric acid can be used to treat or prevent kidney stones by making urine less acidic.

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Pancreas
Bicarbonate
Enzymes

The pancreas has two main functions related to digestion: secreting digestive enzymes and secreting a bicarbonate-rich solution.

Enzyme Secretion: Acinar cells produce enzymes like amylase, lipase, and proteases, which are essential for breaking down carbohydrates, fats, and proteins.

Amylase: Breaks down complex carbohydrates (starches) into simpler sugars.

Lipase: Breaks down fats.

Proteases: Break down proteins. These are secreted in inactive forms and activated in the small intestine, and include enzymes like trypsin and chymotrypsin.

Pancreas
Serine Protease

Amylase
Lipase
Proteases
Trypsin
Chymotrypsin
Bicarbonate
Serine
Histidine
Aspartate
Magnesium
Potassium

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Serine
Glutamine
NMDA
Brain

For the NMDA receptor to become fully active, both glutamate and a co-agonist (either D-serine or glycine) must bind to it simultaneously.

When both glutamate and D-serine bind to their respective sites on the NMDA receptor, the channel opens, allowing calcium ions (Ca2+) to enter the neuron.

This influx of calcium is critical for many brain functions, including learning and memory through processes like synaptic plasticity, particularly long-term potentiation (LTP).

Astrocytes, which are glial cells in the brain, play a key role in this process by synthesizing and releasing D-serine to modulate NMDA receptor activity.

Glutamate stimulates astrocytes to produce and release d-serine, a co-agonist for NMDA receptors, from the conversion of l-serine by the enzyme serine racemase.

Serine racemase is an enzyme that converts L-serine into D-serine. This is significant because D-serine is a co-agonist of the NMDA receptor, a key component of neuronal signaling in the brain. The enzyme plays a crucial role in the brain's neurotransmission processes.

Step-by-step breakdown

Step 1: Oxidation of 3-PG
3-phosphoglycerate (3-PG), a product of glycolysis or gluconeogenesis, is oxidized to 3-phosphohydroxypyruvate.

Step 2: Transamination with glutamate

The enzyme 3-phosphoserine aminotransferase catalyzes a transamination reaction where glutamate donates an amino group to 3-phosphohydroxypyruvate, forming 3-phosphoserine.

Step 3: Dephosphorylation to L-serine

Phosphoserine phosphatase then removes the phosphate group from 3-phosphoserine, resulting in the formation of L-serine and inorganic phosphate.