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80 Cards in this Set
- Front
- Back
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How do we store Amino Acids?
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We can't. They must be used up.
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What are the 2 Major Steps in the Catabolism of Amino Acids?
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-1 - Removal of Amino Groups by Transamination and Subsequent Oxidative Deamination
-2 - Carbon of Alpha-Ketoacids are converted to common Intermediates of the Energy-Producing, Metabolic Pathway |
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Where are most Proteases secreted from?
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Pancreas
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What kinds (how big) of peptide products can enter the epithelial cells?
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Amino Acids and Dipeptides
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Through what mechanism are AAs and Dipeptides transported into the Cell?
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Active Transport
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What happens in Cystinuria?
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-Transport Systems have a Defect in Cysteine Uptake
-Results in Inability to Reabsorb Cysteine at PCT -Cysteine Accumulates -Leads to Stones of Cysteine in the Urinary Tract |
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What enzyme Catalyzes Transamination?
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Aminotransferase
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Where in the cell does Transamination occur?
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Cytosol
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During Transamination, where does the Amine group go? How? What forms?
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-Alpha-Ketoglutarate takes the Amine Group
-Catalyzed by Aminotransferase -Glutamate |
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During which process is Alpha-Ketoglutarate converted to Glutamate?
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Transamination
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Reactants, Products, and Enzyme of Transamination.
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-Amino Acid and Alpha-Ketogluturate
-Alpha-Keto Acid and Glutamate -Aminotransferase |
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In what types of cells can Transamination occur? Where does this happen most often? What does this mean?
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-Any type of Cell
-Liver and Kidney -Amino Acid Breakdown most often begins in the Liver and Kidney |
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What is ALT? What does it do? Where is it found?
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-Alanine Aminotransferase
-Transfers Amino Group from Alanine to Alpha-Ketoglutarate -Liver |
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What reaction does ALT participate in? What does it stand for?
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-Transamination of Alanine
-Stands for the good of all humanity (Alanine Aminotransferase) |
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What reaction does ALT participate in? What are the products?
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-Transamination of Alanine
-Pyruvate and Glutamate |
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Transamination of which AA results in Pyruvate? Which Enzyme catalyzes this reaction?
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-Alanine
-ALT (Alanine Aminotransferase) |
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What is AST? What does it do? Where is it found?
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-Aspartate Aminotransferase
-Funnels Amino Acids away from Glutamate. Gives Amine from Glutamate to Oxaloacetate to reform Alpha-Ketogluturate and form Aspartate -Liver and Muscles |
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What reaction does AST participate in? What does it stand for?
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-Oxaloacetate and Glutamate to form Alpha-Ketoglutarate and Aspartate
-Aspartate Aminotransferase |
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Transamination of which molecule results in Aspartate? Which Enzyme catalyzes this reaction?
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-Oxaloacetate
-Aspartate Aminotransferase |
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What reaction does ALT participate in? What are the reactants? Product? What is transferred?
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-Oxaloacetate and Glutamate to form Alpha-Ketoglutarate and Aspartate
-Amine Group |
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What is Pyrodoxal Phosphate?
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Vitamin B6
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Which molecule is used as a Coenzyme for AST (Aspartate Aminotransferase)?
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Vitamin B6 - Pyrodoxal Phosphate
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Vitamin B6 is used as a Coenzyme for the activity of which enzyme?
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AST
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What the fuck is so important about Aspartate formation from Oxaloacetate using AST?
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Aspartate is a source of Nitrogen in the Urea Cycle
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Where does Oxidative Deamination take place?
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Liver and Kidney
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Which molecule is Oxidatively Deaminated after Aminotransferases have performed their function?
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Glutamate
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What happens to Amine Groups after Oxidative Deamination?
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Released as free Amine Groups
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Which enzyme mediates Oxidative Deamination?
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Glutamate Dehydrogenase (Think about which molecule is being deaminated you fucktard)
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What reaction does Glutamate Dehydrogenase play a role in? What does it require as Coenzymes?
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-Oxidative Deamination
-NAD+ or NADP+ |
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Which molecules Activate Oxidative Deamination? Inhibit?
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-ADP and GDP
-ATP and GTP |
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What can Alpha-Ketoglutarate do after Transamination and Oxidative Deamination?
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Participate in Deamination or TCA Cycle to get energy
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What steps are involved in the Synthesis of Amino Acids? What makes this process easy to remember?
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-Reductive Amination and Transamination
-Same Steps as Disposal of AAs but reversed and catalyzed by same Enzymes |
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What Happens to Ammonia after Disposal of AAs? Why?
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-Transported to the Liver to Filter and Dispose of
-Its fucking toxic!!! |
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What are the 2 Mechanisms of Transport of Ammonia to the Liver? How does we get this form that is transported?
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-Glutamine Synthetase combines Ammonia with Glutamate to form Glutamine. Glutamine then travels to the Liver carrying Ammonia.
-Ammonia is added to Alpha-Ketoglutarate to give Glutamate. Pyruvate picks up Amine to form Alanine which transports it to Liver |
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Which Mechanism is responsible for the transport of Ammonia in most tissues? Explain the Mechanism.
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-Glutamine Synthetase combines Ammonia with Glutamate
-Forms Glutamine -Glutamine travels to the Liver carrying Ammonia -Glutaminase frees Glutamine and releases Amine Group |
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Which Mechanism is responsible for the transport of Ammonia in muscles? Explain the Mechanism.
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-Ammonia is added to Alpha-Ketoglutarate
-Results in Glutamate -Pyruvate picks up Amine from Glutamate to form Alanine -Alanine transports it to Liver, where it is deaminated |
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What is the sources of Nitrogen and Carbon in Urea?
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-CO2
-Ammonia and Aspartate |
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Where is Urea produced?
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Liver
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Where is Urea Excreted?
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Kidney
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What is the 1st step in the Urea Cycle?
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Formation of Carbamoyl Phosphate
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How many ATPs are used in the 1st step of the Urea Cycle? What is the 1st Step in the Urea Cycle?
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-2
-Formation of Carbamoyl Phosphate |
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Which reaction does Carbamoyl Phosphate Synthetase I catalyze?
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-Formation of Carbamoyl Phosphate
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Where does the 1st step of the Urea Cycle occur? What is the 1st Step in the Urea Cycle?
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-Mitochondria in the Liver
-Formation of Carbamoyl Phosphate |
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Where does the 1st Nitrogen in Urea come from? Which step?
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-Ammonia
-1st Step: Formation of Carbamoyl Phosphate |
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Where does the 2nd Nitrogen in Urea come from? Which step?
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-L-Aspartate
-3rd Step-Formation of Arginosuccinate |
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What is the 3rd Step of the Urea Cycle? What happens? Why is this Step Important?
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-Formation of Arginosuccinate
-L-Citrulline is Combined with L-Asparate using 1 ATP -Gives us the 2nd Nitrogen in Urea |
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What is the Final Step in the Urea Cycle? What results?
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Cleavage of Arginine to Ornithine and Urea
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Which enzyme catalyzes the Cleavage of Arginine to Ornithine and Urea?
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Arginase
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Which step in the Urea Cycle does the enzyme Arginase catalyze?
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-Final Step
-The Cleavage of Arginine to Ornithine and Urea |
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Where is Arginase found? What is the significance of this?
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-Liver only
-Urea can only be formed in the Liver since the final step of the Urea Cycle needs Arginase |
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Where are the 2 Nitrogens in Urea from both Directly and Indirectly? Explain.
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-Ammonia (1st Step) and Aspartate (3rd Step)
-Originally both from Glutamate: 1) Ammonia was transported to the Liver bound to Glutamate. 2) Glutamate transferred an Amine Group to Oxaloacetate to form Aspartate |
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How many ATP does the Urea Cycle overall cost?
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3
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Which enzymes would be involved the reversal of the Urea Cycle?
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None you fucking idiot. Its irreversible synthesis
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What is the Rate-Limiting Step in the Urea Cycle?
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-Step 1
-Formation of Carbamoyl Phosphate |
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Which enzyme catalyzes the Rate-Limiting Step of the Urea Cycle? What is this step? What else is important to remember about this step?
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-Carbamoyl Phosphate Synthetase I
-Carbamoyl Phosphate Formation -Ammonia supplies the First Nitrogen in Urea |
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Where are the 2 Nitrogens in Urea from?
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-1 - Ammonia
-2 - Aspartate |
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What is the the Rate-Limiting Step in the Urea Cycle? What activates it?
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-Carbamoyl Phosphate Formation
-NAG - N-Acetylglutamate |
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What role does NAG (N-Acetylglutamate) play in the Urea Cycle?
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-Allosteric Activator of Carbamoyl Phosphate Synthetase I
-Carbamoyl Phosphate Synthetase I catalyzes the 1st step, formation of Carbamoyl Phosphate |
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How is NAG (N-Acetylglutamate) formed? Why is it important in the Urea Cycle?
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-Glutamate and Acetyl CoA join to form NAG
-Activates Carbamoyl Phosphate Synthetase I |
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Which enzyme catalyzes the formation of NAG?
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Acetylglutamate Synthetase
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What activates Carbamoyl Phosphate Synthetase I?
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NAG - N-Acetylglutamate
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What activates Acetylglutamate Synthetase? What does Acetylglutamate Synthetase do? Why is this important?
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-Arginine
-Catalyzes formation of NAG from Glutamate and Acetyl CoA -NAG activates Carbamoyl Phosphate Synthetase I and the Urea Cycle |
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What promotes NAG Synthesis?
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-Arginine - From a Protein-Rich Meal
-Glucagon |
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What molecule is the precursor of both Nitrogen Atoms of Urea?
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-GLUTAMATE
-If you forget this, I will beat the shit out of you |
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How do Most Tissues get rid of Ammonia?
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-Glutamine Syntetase Combines Glutamate with Ammonia to form Glutamine
-Glutamine Travels to Liver -Glutaminase cleaves Glutamine to form Ammonia and Glutamate |
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How do Muscles get rid of Ammonia?
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-Ammonia is added to Alpha-Ketoglutarate to give Glutamate
-Pyruvate picks up the Amine from Glutamate to give Alanine -Alanine is Deaminated in the Liver -Results in Free Amonnia and Pyruvate |
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What are the Sources of Ammonia in the Body?
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-Amino Acids
-Glutamine -Bacterial Action in the Intestine -Amines -Purines and Pyrimidines |
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What are some causes of Hyperammonemia?
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Compromised Liver Function from:
-Genetic Defects of the Urea Cycle -Liver Diseases -ETC Problems |
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What are some symptoms of Ammonia Intoxication from Hyperammonemia?
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Tremors, Slurring of Speech, Somnolence, Vomiting, Cerebral Edema, Blurring of Vision
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What are some Acquired Hyperammonemias?
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-Liver Diseases caused by Viral Hepatitis, Ischemia, and Hepatotoxin Cirrhosis
-Portal Blood In Circulation |
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What are some Hereditary Hyperammonemias?
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-Defects in Enzymes of Urea Cycle
-Mental Retardation |
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What are 2 drugs used to Treat Hyperammonemia?
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-Phenylbutyrate
-Benozoate |
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What is Phyenylbutyrate used for?
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Treatment of Hyperammonemia
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What is Benzoate used for?
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Treatment of Hyperammonemia
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What are 3 Ways to Treat Hyperammonemia?
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-Limit Protein in the Diet
-Administration of Phenylbutyrate or Benzoate -Administration of Arginine |
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How does Administration of Arginine help treatment Hyperammonemia?
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-Activates NAG Synthetase
-Activates NAG Formation -NAG activates Carbamoyl Phosphate Synthetase I -1st step of Urea Cycle |
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Which reaction is mediated by Glutamate Dehydrogenase? Where does this occur?
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-Oxidative Deamination
-Liver and Kidney |
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Where does the Urea Cycle Occur?
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Liver
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What is the Regulatory Step in the Urea Cycle?
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-Formation of Carbamoyl Phosphate
-1st Step |
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During which Steps of the Urea Cycle is Energy put in? How much Energy? What happens in these steps? What else is important about these steps?
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-1st Step - Formation of Carbamoyl Phosphate from Ammonia and CO2 - 2 ATP
-3rd Step - Formation of Arginosuccinate from L-Citrulline and L-Aspartate - 1 ATP -These are the 2 Steps that deliver Nitrogen for Urea |
