Term
| what substances does nitrogen metabolism include |
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Definition
| amino acids, proteins, heme, nucleotide metabolism |
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Term
|
Definition
|
|
Term
| why do we need to get rid of nitrogen |
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Definition
| there is no way to store it and it is reactive in the body |
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|
Term
| where are most amino acids obtained |
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Definition
| diet, protein turn over, synthesis of non-essential amino acids |
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Term
| what are amino acids used for |
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Definition
| systhesis of proteins, synthesis of nitrogen containing compounds (nucleotides, heme), use of carbond skeletons of amino acids to make compounds for energy |
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Term
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Definition
| net loss/ gain of amino acids to the bodys pool |
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Term
| what is the half life of a protein related to |
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Definition
|
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Term
| what condition would cause a protein to degrade more rapidly |
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Definition
| misfolded or unstable proteins |
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Term
| what causes a glucose-6-phosphate dehydrogenase deficiency |
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Definition
| it is degraded in a deficiency because of a missense mutation making it less stable |
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Term
| what structure characteristics of proteins would affect protein degredation or half life |
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Definition
| amino acid at the N terminus (because it determines post translational modifications), PEST sequence codes for early degradation |
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Term
| what are the ways to degrade proteins |
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Definition
|
|
Term
| how are proteins sent to proteasomes to be degraded |
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Definition
|
|
Term
| what proteins are degraded by the lysosome |
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Definition
| extracellular and membrane bound |
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Term
| skipping enzyme process, give the general layour for the path of protein drgration starting with ingestion |
|
Definition
1. low pH in stomach denatures
2. pepsin in the stomach
3. small intestine stimulation by CCK and secretin
4. zymogens released by pancreas
5. only single AA remain
6. AA absorbed and go to liver to decide their fate |
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Term
| what are the purposes for the low pH in the stomach |
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Definition
| primairly to kill microbes but also denatures proteins |
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|
Term
| what type of enzyme is pepsin |
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Definition
|
|
Term
|
Definition
| zymogen cell releases pepsinogen and the low pH of the stomach activates it to pepsin |
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Term
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Definition
| digest proteins or turn more pepsinogen into pepsin |
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Term
| what stimulates for the release of enzymes from the pancreas |
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Definition
| chyme enters the small intestines stimulating CCK and secretin release, they then stimulate the pancreas |
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Term
| what are examples of active pancreatic enzymes |
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Definition
|
|
Term
|
Definition
| the pancreas releases trypsinogen into the small intestines, intestinal cells release enteropeptidase which activates trypsinogen into trypsin |
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Term
|
Definition
| it can activate other pancreatic enzymes or turn more trypsinogen to trypsin |
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Term
| what turns chymotrypsinogen into chymotrypsin |
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Definition
|
|
Term
| what turns pancreatic zymogens into acrive enzymes |
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Definition
|
|
Term
| how are pancreatic enzymes classified |
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Definition
| endopeptidases, exopeptidases |
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Term
|
Definition
| cleaves inside a peptide sequence |
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Term
|
Definition
| cleaves from the ends of a peptide sequence |
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|
Term
| what are issues with protein digestion associated with |
|
Definition
| other diseases that affect the pancreas like cystic fibrosis, pancreatitis |
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|
Term
| what is another name for celiac disease |
|
Definition
|
|
Term
| what causes the symptoms of celiac diasese |
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Definition
| the intestines have an allergic reaction to gluten damaging intestinal cells leading to malabsorption |
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|
Term
|
Definition
| kidney cant absorb some amino acids causing them to accumulate, percipitate and cause kidney stones |
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Term
|
Definition
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|
Term
| why are the amino acids involved with cystinuria grouped the way they are |
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Definition
| because they have a common transporter |
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|
Term
| what amino acids cant be absorbed in cystinuria |
|
Definition
| cystine, ornithine, lysing, arginine |
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|
Term
| what is another name for kidney stones |
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Definition
|
|
Term
| in what forms is nitrogen transported |
|
Definition
| glutamate, glutamine, alanine, aspartate |
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|
Term
| what is a majority of nitrogen transported as |
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Definition
|
|
Term
|
Definition
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Term
|
Definition
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|
Term
|
Definition
|
|
Term
|
Definition
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|
Term
| what are the types of aminotransferases |
|
Definition
| alanine amino transferase (ALT), asparatate amino transferase (AST) |
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|
Term
| what can aminotransferases be indicators of, where are they |
|
Definition
| tissue damage (heart attack, liver damage), in the blood |
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|
Term
| what does aminotransferase need to work |
|
Definition
| pyridoxal phosphate cofactor |
|
|
Term
| where does pyridoxal phosphate come from |
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Definition
|
|
Term
| what does amino transferase convert |
|
Definition
| it combines a-ketogluterate and an amino acid to make glutamate and a-ketoacid or vice versa |
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|
Term
| what is the difference between aminotransferase and glutamate DH |
|
Definition
| with glutamate DH ammonia is a product or substrate instead of transferred |
|
|
Term
| where is glutamate DH mostly located |
|
Definition
|
|
Term
| what does glutamate DH convert |
|
Definition
| glutamate and NAD into a-ketogluterate, NADH, and NH3 or in reverse |
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|
Term
| what is the normal function of glutamine synthase |
|
Definition
| mostly in tissues to get their nitrogrn into the blood to go to the liver |
|
|
Term
| what does glutamine synthase convert |
|
Definition
| glutamate, ATP, NH3 into ADP and glutamine |
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|
Term
| what does glutaminase convert |
|
Definition
| glutamine and ADP into ARP, NH3, and glutamate |
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|
Term
| what is the normal function of glutaminase |
|
Definition
| release ammonia and glutamate at the liver |
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Term
| in general, what is the major route of nitrogen disposal |
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Definition
| tissue sends out glutamine (alanine in muscle), it is taken up by the liver, then into the urea cycle |
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|
Term
| after nitrogen disposal where do carbon skeletones go |
|
Definition
| into biosynthetic pathways |
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|
Term
| what is the main system for nitrogen disposal |
|
Definition
|
|
Term
| explain how the urea cycle is completely recyclable |
|
Definition
| C and O are released as CO2 and amino comes from free ammonia and asparatate, C used as carriers are regenerated |
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|
Term
| what is the first enzyme in the ures cycle |
|
Definition
| carbomyl phosphate synthase 1 |
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|
Term
| what is the rate limiting enzyme in the urea cycle |
|
Definition
| carbomyl phosphate synthase 1 |
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|
Term
| what increases the transcription of carbomyl phosphate synthase 1 |
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Definition
|
|
Term
| what increases acetylglutamate production |
|
Definition
| acetyl CoA, glutamate, arginine |
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|
Term
| what can cause am increase in acetyl CoA, glutamate, and arginine |
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Definition
|
|
Term
| what does carbomyl phosphate synthase 1 catalyze |
|
Definition
| ammonia, CO2, and ATP to carbomyl phosphate |
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|
Term
| what is the second enzyme in the urea cycle |
|
Definition
| ornathine transcarbomylase |
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|
Term
| what does ornathine transcarbomylase catalyze |
|
Definition
| ornathine and carbomyl phosphate to citrulline |
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|
Term
| where do the first two steps in the urea cycle take place in |
|
Definition
|
|
Term
| what intermediates in the urea cycle can go through the mitochondrial membrane |
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Definition
|
|
Term
| after citrulline enters the cytoplasm, what happens to it in the urea cycle |
|
Definition
| it joins asparatate adding another amino grouop, it goes through common sugar intermediates, under the enzyme arginase releases free urea, turns back into ornithine |
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|
Term
| where does free urea released from the urea cycle go |
|
Definition
| from the liver to the blood then kidney to urine |
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|
Term
| how is ammonia and asparatate gotten into the liver cell |
|
Definition
1. a-ketogluterate is converted to glutamate
2.A. glutamate DH turns it into ammonia
2.B. aminotransferase turns it into aspartate |
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|
Term
| what places in the body does ammonia come from |
|
Definition
| tissues, diet, microbes, exogenous enzymes, muscle, kidney |
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|
Term
| how does ammonia from the tissues, diet, microbes in the gut, and exogenous enzymes get to the liver |
|
Definition
| ammonia + glutamate --glutamine synthase--> glutamine --> sent to liver |
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|
Term
| how does ammonia from the muscle get to the liver |
|
Definition
| ammonia + pyrivate --glutamine synthase--> alanine --> sent to the liver |
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|
Term
| what happens to glutamine and alanine once they get to the liver |
|
Definition
| glutaminase turns them into ammonia and glutamate/pyruvate |
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|
Term
| what happens to ammonia produced by the kidney, what other function does this play |
|
Definition
| it is excreted into the urine, can also contribute to the body's acid base balance |
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|
Term
|
Definition
| elevated ammonia in the blood |
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|
Term
| what are the causes of hyperammonemia |
|
Definition
| liver failure, liver dysfunction, urea cycle enzyme defect |
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|
Term
| what is a urea cycle enzyme defect classified as |
|
Definition
| inborn error of metabolism |
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|
Term
| what are the effects / symptoms of hyperammonemia |
|
Definition
| mental redardation and death due to nervous tissue effects, shows up shortly after birth |
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|
Term
| what is a type of hyperammonemia disease |
|
Definition
| ornithine transcarbomylase deficiency |
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|
Term
| what is the inheritance of ornithine transcarbomylase deficiency |
|
Definition
|
|
Term
| what is the treatment for hyperammonemia |
|
Definition
| diet motification (low protein), phenylbuterate |
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|
Term
| what is the reaction phenylbuterate causes in the body |
|
Definition
| once in the body it is naturally comverted to phenylacetate which combines with glutamate to make phenylacetylglutamine, the kidney will absorb that and put it in urine |
|
|
Term
| explain the theory behind how phenylbuterate works |
|
Definition
| glutamine is made for protein synthesis, removing N lessening the urea cycle need, reducing ammonia |
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