Clinical Correlates 1 Functional Chemistry Flashcards
HCl is produced by the parietal cells of the stomach. The H+-K+ ATPase (the proton pump) in the cell membrane is responsible for producing as much as 2 L of acidic gastric fluid per day. Some individuals have a condition known as gastroesophageal reflux disease (GERD), which results from reflux of HCl back into the esophagus. This condition creates a burning sensation in the chest, along with cough and even shortness of breath. The proton pump can be inhibited by ??
proton pump inhibitors (PPIs) such as omeprazole.
The carbonic anhydrase inhibitor, ____, blocks the above reaction and is used for the treatment of glaucoma as well as altitude sickness.
acetazolamide
The normal pH range of arterial blood is ___.
a. The major buffers of blood are bicarbonate (HCO3
/H2CO3) and hemoglobin (Hb/HHb).
b. These buffers act in conjunction with mechanisms in the kidneys for excreting protons and mechanisms in the lungs for exhaling CO2 to maintain the pH within the
normal range.
7.37 to 7.43.
___ ___ can result from accumulation of metabolic acids (lactic acid or the ketone bodies, b-hydroxybutyric acid, and acetoacetic acid) or ingestion of acids or compounds that are metabolized to acids (e.g., methanol, ethylene glycol).
Metabolic acidosis
Metabolic ____ is due to increased HCO3, which is accompanied by an increased pH. Acid-base disturbances lead to compensatory responses that
attempt to restore normal pH.
For example, a metabolic acidosis causes hyperventilation and the release of CO2, which tends to raise the pH. During metabolic acidosis, the kidneys excrete NH4+, which contains H+ buffered by ammonia:
alkalosis
The glycoside digitalis and its derivatives are of clinical significance because they inhibit the ___ on cell membranes. Such drugs are used in the treatment of congestive heart failure.
Na+-K+ ATPase
The oxidation of glucose by ____ (a highly specific test for glucose) is used by clinical and other laboratories to measure the amount of glucose in
urine using a dipstick.
glucose oxidase
Glucose forms ___ acid. Conjugation with glucuronic acid makes lipid compounds more water soluble (e.g., bilirubin diglucuronide).
glucuronic
Infants have a decreased ability to conjugate glucuronic acid onto drugs such as chloramphenicol. Administration of this antibiotic during the neonatal period can result in elevated plasma levels of the drug and a fetal shocklike syndrome referred to as ???
gray baby syndrome.
Because dipsticks only detect glucose, many clinical laboratories use a chemical test for ____, a modified Benedict test for reducing sugars, which also will detect the presence of sucrose, galactose, and fructose. Most newborn and infant urine is routinely screened for reducing sugars to detect inborn errors in metabolism.
reducing sugars
Glucose is reduced to sorbitol, and galactose to galactitol.
Sorbitol does not readily diffuse out of cells. As it accumulates in cells, it causes osmotic damage to cells of the nervous system, resulting in cataracts and
neuropathy.
Glycosylation of proteins: Addition of sugar moieties to proteins can alter proteins in many ways, including modifying their function, protecting them from proteolysis, and directing their intracellular traffic, as well as direct cellular movement.
Patients with leukocyte adhesion deficiency (LAD) II have a congenital deficiency in the ability to glycosylate ligands for cell surface selectins, which mediate immune cell migration. Such patients are prone to recurrent life-threatening infections.
_____ is a glycosaminoglycan, which is an important anticoagulant found in the granules of mast cells. It can be used during the treatment of myocardial infarction as well as for the prevention of deep venous thrombosis during hospitalizations.
Heparin
The__ ___ infects cells by binding its viral hemagglutinin to sialic acid on the surface of epithelial cells.
influenza virus
____ functions as an inhibitory neurotransmitter in the brainstem and spinal cord. Its actions are antagonized by the rodenticide strychnine, leading to twitching and muscle spasm.
Glycine