Biochemistry Chapter: Amino Acid Metabolism

<p>α-Ketoglutarate (D)</p> Signup and view all the answers

<p>GTP (D)</p> Signup and view all the answers

<p>It acts as an intermediate. (C)</p> Signup and view all the answers

<p>Arginine (C)</p> Signup and view all the answers

<p>From free ammonia and aspartate (B)</p> Signup and view all the answers

<p>ADP (D)</p> Signup and view all the answers

<p>Transamination of α-keto acids (A)</p> Signup and view all the answers

<p>Sucrose (D)</p> Signup and view all the answers

<p>Transamination (C)</p> Signup and view all the answers

<p>Hydroxylation of phenylalanine (D)</p> Signup and view all the answers

<p>Formation of carbamoyl phosphate (B)</p> Signup and view all the answers

<p>Argininosuccinase (C)</p> Signup and view all the answers

<p>Increases CPS I activity (D)</p> Signup and view all the answers

<p>Alanine (C), Valine (D)</p> Signup and view all the answers

<p>Increase in glutamate concentration (C)</p> Signup and view all the answers

<p>Acetyl-CoA (A)</p> Signup and view all the answers

<p>Ketogenic pathway (C)</p> Signup and view all the answers

<p>Essential amino acids (B)</p> Signup and view all the answers

<p>To kill some bacteria (A)</p> Signup and view all the answers

<p>They are rapidly degraded. (A)</p> Signup and view all the answers

<p>By hydrochloric acid or autocatalytically by pepsin (B)</p> Signup and view all the answers

<p>Amino acids synthesized de novo. (A)</p> Signup and view all the answers

<p>They cleave large polypeptides into oligopeptides and amino acids (D)</p> Signup and view all the answers

<p>As urea. (B)</p> Signup and view all the answers

<p>Cholecystokinin and secretin (B)</p> Signup and view all the answers

<p>They hydrolyze proteins for absorption. (D)</p> Signup and view all the answers

<p>It cleaves N-terminal residues from oligopeptides (D)</p> Signup and view all the answers

<p>Loss of waste products. (B)</p> Signup and view all the answers

<p>Removal of the α-amino group (C)</p> Signup and view all the answers

<p>Large intestine. (C)</p> Signup and view all the answers

<p>It can be incorporated into other compounds or excreted (D)</p> Signup and view all the answers

<p>Deamination. (A)</p> Signup and view all the answers

<p>Urea (A)</p> Signup and view all the answers

<p>It can be transformed into glucose or ketone bodies. (D)</p> Signup and view all the answers

<p>To transfer amino groups to α-ketoglutarate (D)</p> Signup and view all the answers

<p>Pyridoxal-5'-phosphate (PLP) (C)</p> Signup and view all the answers

<p>An α-keto acid (D)</p> Signup and view all the answers

<p>It donates its amino group to oxaloacetate. (B)</p> Signup and view all the answers

<p>Ammonia (B)</p> Signup and view all the answers

<p>It involves the transfer of an α-amino group. (B)</p> Signup and view all the answers

<p>Alanine aminotransferase (ALT) (B)</p> Signup and view all the answers

<p>It produces aspartate and regenerates α-ketoglutarate. (A)</p> Signup and view all the answers

The pool of amino acids in the body that is constantly being replenished and depleted by various metabolic processes.

The continuous breakdown and synthesis of proteins in the body, ensuring a constant turnover and renewal.

The process of breaking down proteins into smaller peptides and amino acids for absorption in the small intestine.

Enzymes that break down proteins into smaller units.

A process where the amino group of an amino acid is transferred to a ketoacid, forming a new amino acid and a ketoacid.

A process where the amino group of an amino acid is removed, forming ammonia and a ketoacid.

A compound synthesized by the liver that carries excess nitrogen from protein breakdown for excretion.

The process of converting the carbon skeleton of amino acids into glucose or ketone bodies for energy production.

A metabolic process where the amino group from an amino acid is transferred to α-ketoglutarate, forming glutamate and a new α-keto acid. This is the first step in amino acid catabolism.

Enzymes that catalyze the transfer of amino groups during transamination reactions.

A coenzyme essential for aminotransferases. It's derived from vitamin B6.

The sum of all the amino acids in the body that are available for use in metabolic processes.

An aminotransferase enzyme that catalyzes the transfer of an amino group from alanine to α-ketoglutarate, forming pyruvate and glutamate. Primarily functions during amino acid catabolism.

An aminotransferase enzyme that catalyzes the transfer of an amino group from glutamate to oxaloacetate, forming α-ketoglutarate and aspartate. Primarily functions during amino acid catabolism.

The process of removing the amino group from an amino acid, generating ammonia and a ketoacid.

An enzyme that catalyzes the oxidative deamination of glutamate, generating ammonia and α-ketoglutarate.

Hydrochloric acid (HCl) is a strong acid found in the stomach. It helps break down food by denaturing proteins, a process that makes them more susceptible to enzymatic digestion.

Pepsin is a protease, an enzyme responsible for breaking down proteins into smaller peptides. Pepsinogen, its inactive form, is secreted by the stomach's chief cells.

Pancreatic proteases are a group of enzymes that further break down large polypeptides produced in the stomach, into smaller oligopeptides and amino acids.

Aminopeptidase is an exopeptidase located on the intestinal lining. It works by removing the N-terminal amino acid from oligopeptides, producing even smaller peptides and free amino acids.

Amino acids can be used for energy or biosynthesis. Some amino acids can enter the urea cycle. Fumarate and oxaloacetate are key intermediates in the urea cycle.

Transamination is a chemical reaction where an amino group from an amino acid is transferred to a keto acid, forming a new amino acid and a new keto acid. This reaction is catalyzed by aminotransferases, which require pyridoxal phosphate (PLP) as a coenzyme.

The urea cycle is a metabolic pathway that converts ammonia, a toxic waste product of amino acid metabolism, into urea, which can be safely excreted in the urine.

The process of removing an amino group from glutamate, converting it to α-ketoglutarate and releasing ammonia (NH3).

An enzyme that catalyzes the oxidative deamination of glutamate.

The enzyme uses either NAD+ or NADP+ as a coenzyme.

It is an intermediate of the TCA cycle, which is involved in energy production.

It activates glutamate dehydrogenase, increasing the flow through the TCA cycle and boosting ATP production.

It inhibits glutamate dehydrogenase, slowing down the TCA cycle when energy levels are high.

It is a key molecule in the urea cycle, carrying excess nitrogen from protein breakdown to the kidneys for excretion.

The process of converting ammonia into urea, which is less toxic and can be excreted in urine.

The essential amino acids are those the body cannot synthesize and must be obtained through dietary sources. They are vital for various bodily functions, including protein synthesis, hormone production, and enzyme activity.

The synthesis of nonessential amino acids involves the transfer of an amino group from one molecule to another. This process is called transamination and utilizes existing amino acids and metabolic intermediates.

The amino group from amino acids is converted into ammonia, a nitrogenous waste product. This process is called deamination. The ammonia is then further processed in the liver to form urea for excretion.

The carbon skeleton of amino acids can be used for energy production. They can be converted into glucose through gluconeogenesis or into ketone bodies, which are alternative energy sources.

Carbamoyl phosphate synthetase I (CPS I) is the rate-limiting enzyme in the urea cycle, catalyzing the initial step of converting ammonia and bicarbonate into carbamoyl phosphate.

N-acetylglutamate is an allosteric activator of CPS I, meaning it binds to the enzyme and increases its activity. This regulation ensures that the urea cycle operates efficiently when there is an excess of ammonia.

The process of breaking down amino acids into their constituent parts, releasing ammonia as a byproduct.

Glucogenic amino acids can be converted into glucose, a major energy source for the body, whereas ketogenic amino acids are broken down into ketone bodies, which can also be used as fuel.

The urea cycle is a complex process that involves several steps, including the formation of carbamoyl phosphate, citrulline, argininosuccinate, arginine, and ultimately urea.