Bio 1107 Deamination Flashcards

Questions and Answers

What does deamination metabolize?

Proteins

Where does deamination occur?

Mitochondria

What is deamination?

The enzymatic removal of an amine group (NH2) from an amino acid.

What does deamination produce?

A 2-carbon acetyl acid connected to the R side chain Signup and view all the answers

What is a protein?

Amino acids connected by peptide bonds to form a polypeptide or protein. Signup and view all the answers

What is the first step of deamination?

Depolymerize the polymer into its amino acid monomers. Signup and view all the answers

What is the pH of your stomach?

1 or 2 Signup and view all the answers

Can your stomach break down proteins?

True Signup and view all the answers

Why aren't enzymes located in the stomach?

It's not an ideal environment. Signup and view all the answers

How do you digest proteins?

Your stomach releases proteases to help digest proteins at a very low pH. Signup and view all the answers

What proteases do your stomach secrete?

Trypsin, Chymotrypsin, and Pepsin Signup and view all the answers

What do proteases do?

They are enzymes that break down the peptide bonds. Signup and view all the answers

What was the experimental setup to determine what pH each protease functioned best in?

Each protease was mixed with a substrate and pH. They measured the enzyme activity for each pH. Signup and view all the answers

What pH does pepsin function best at?

pH of 2 Signup and view all the answers

What pH does trypsin function best at?

pH of 8 Signup and view all the answers

What pH does chymotrypsin function best at?

pH of 10 Signup and view all the answers

Where is pepsin located?

In the stomach Signup and view all the answers

Where are trypsin and chymotrypsin located?

In the small intestine Signup and view all the answers

What happened when pepsin was incubated with three different protein substrates, and its degradation was monitored over 4 hours?

Hemoglobin=iron=red meat=easily digested by pepsin; Ovalbumin=poorly digested by pepsin-> sent to small intestine to be digested. Signup and view all the answers

What happens once the proteases have broken down the protein into amino acids?

Cellular respiration (deamination) converts the amino acids into energy (ATP). Signup and view all the answers

What is significant about an R-group?

It distinguishes amino acids from each other - enzymes recognize different R groups. Signup and view all the answers

What does the accumulation of GDP mean?

Energy levels are low Signup and view all the answers

What happens when GDP accumulates?

GDH is allosterically activated to produce more NADH and 2-carbon acetyl groups (deamination). Signup and view all the answers

What would happen if all amino acids were deaminated upon arrival to the mitochondria?

The mitochondria couldn't translate the proteins encoded in its genome, which would be fatal. Signup and view all the answers

Proteins can be ____

Recycled Signup and view all the answers

What is GDH?

An enzyme Signup and view all the answers

What four molecules allosterically modulate GDH?

ATP, ADP, GTP, & NADH (high energy) Signup and view all the answers

What inhibits deamination by GDH?

ATP and GTP. GTP more so than ATP. Signup and view all the answers

What does GDH consume?

1 Amino acid and 1 NAD+ Signup and view all the answers

What does GDH produce?

<ol> <li>Ammonia molecule; 2) NADH; 3) The oxidized amino acid lacking its nitrogen atom (CO)</li> </ol> Signup and view all the answers

What is the most important part of deamination?

The enzymatic removal of the amino group (NH2) from amino acids. Signup and view all the answers

What would happen without the regulation of GDH and other deaminating enzymes?

You would convert all of your amino acids to 2-carbon acetyl groups, stress your kidneys, and lose the opportunity to recycle amino acids into new proteins. Signup and view all the answers

What is water's role in deamination?

One H+ = NAD+ -> NADH; One H+ = Amine group (NH2) -> ammonia (NH3); Oxygen = Covalently attached to the carbon that used to be connected to the nitrogen. Signup and view all the answers

What happens to ammonia?

It is converted to urea and filtered out of blood by kidneys. Signup and view all the answers

What is dangerous about high levels of ammonia?

High levels can damage your kidneys. Signup and view all the answers

How much nitrogenous waste does each urea carry?

Each urea carries the nitrogenous waste of two deaminated amino acids. NH2-CO-NH2 Signup and view all the answers

Formation of NADH from water and NAD+ = +/- Delta G?

Large positive delta G +220 kj/mole Signup and view all the answers

Study Notes

Deamination Overview

Deamination metabolizes proteins, specifically by removing an amine group (NH2) from amino acids.
Occurs primarily in the mitochondria, where enzymatic activity leads to energy production.

Proteins and Digestion

Proteins consist of amino acids linked by peptide bonds, forming polypeptides.
The stomach has a highly acidic pH of 1 or 2, aiding the breakdown of proteins via proteases.
Pepsin, trypsin, and chymotrypsin are key proteases secreted for protein digestion.

Protease Functionality

Pepsin operates best at pH 2, while trypsin functions optimally at pH 8, and chymotrypsin operates well at pH 10.
Each protease can act on different substrates; for example, hemoglobin is easily digested, whereas ovalbumin is not.

Role of GDH in Deamination

GDH (Glutamate Dehydrogenase) plays a critical role in deamination, converting amino acids into energy.
It is allosterically activated by GDP accumulation, indicating low energy levels.
GDH consumes one amino acid and one NAD+, producing ammonia, NADH, and an oxidized amino acid.

Regulation of Deamination

Regulation of GDH is crucial to avoid the complete deamination of amino acids, which can be fatal due to the loss of proteins coded by mitochondrial DNA.
High-energy molecules like ATP and GTP inhibit GDH activity, preventing excessive deamination.

Ammonia Handling

The amine group (NH2) is converted to ammonia (NH3), which is subsequently transformed into urea for excretion via the kidneys.
Elevated ammonia levels can be harmful, potentially damaging kidney function.

Nitrogenous Waste

Each urea molecule carries the nitrogenous waste equivalent to two deaminated amino acids, represented as NH2-CO-NH2.
The formation of NADH from water and NAD+ results in a large positive delta G of +220 kJ/mole, indicating an energy-consuming process.

Conclusion

Successful protein metabolism through deamination leads to energy production while maintaining homeostasis and minimizing toxic byproducts.

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Description

Test your knowledge of deamination with these flashcards! Covering key concepts such as the process of deamination, its location, and its metabolic significance, these cards are perfect for students in Bio 1107. Improve your understanding of protein metabolism today.