Cathepsins are activated in the lysosomal pathway **(True/False)**
**True**
2
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Glutamate dehydrogenase is bidirectional. **(True/False)**
**True** - from glutamate to alpha ketoglutarate with high ammonia concentration and the opposite direction with low ammonia concentration
3
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Glutamine synthetase acts in the liver. **(True/False)**
**False** - its helping to synthesize glutamine (glutamate + ammonia → glutamine). Glutamine is synthesized in the tissues because you don’t want free-floating ammonia in your body. Your body wants to pick it up from the tissues, transport and deposit it into the liver to undergo the urea cycle.
4
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Which reacts with carbamoyl phosphate to generate citruline?
1\. aspartate
2\. fumarate
3\. ornithine
4\. ornithine transcarbamylase
3. ornithine because ornithine + carbamoyl phosphate → citruline and the enzyme that helps this reaction occur is ornithine transcarbamylase
5
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Urea is produced in the kidneys. **(True/False)**
**False** - urea is produced in the liver because the urea cycle occurs in the liver cell’s mitochondrion and cytoplasm
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A treatment of hyperammonemia is a high protein diet. **(True/False)**
**False** - need a low protein diet because protein contains amino groups which can be converted into ammonia
7
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The main source of non-erythrocyte heme is in:
1. bone marrow 2. spleen 3. liver 4. kidney
3. Liver
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Hemin is produced when there is reduced heme production. **(True/False)**
**False** - when there’s an abundance of heme it becomes oxidized (loss of H+) and becomes hemin
9
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Hemin acts as an allosteric inhibitor. **(True/False)**
**True** - the abundance of heme results in the production of hemin (heme undergoes oxidation to become hemin). Hemin acts as an allosteric inhibitor to ***delta-aminolevulinic acid (ALA) synthetase*** to prevent the production of ***delta-aminolevulinic acid (ALA)*** and thus overall reduces heme production.
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when 2 delta-aminolevulinic acids (delta-ALA’s) react, what is formed?
porhphobilinogen - the 1st ring of heme
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What is added to protoporphyrin IX to become heme?
1. Phosphate 2. Iron 3. Carboxylic Acid 4. Oxygen
2. Iron (Fe 2+)
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Increased sensitivity of the skin is a symptom of porphyria. **(True/False)**
**True** - porphyria cutanea tarda occurs when there’s a deficiency of ***uroporphyrinogen decarboxylase***
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Where does bilirubin get conjugated with gluconic acid?
1. hepatocytes 2. spleen 3. bile 4. kidneys
1. hepatocytes - liver cells
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When liver damage occurs, there is high levels of conjugated bilirubin. **(True/False)**
**False** - if liver damage occurs, bilirubin cannot become conjugated and there would be high levels of unconjugated bilirubin.
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UDP - glucuronyltransferase helps reduce biliverdin to bilirubin. **(True/False)**
**False** - Biliverdin reductase helps to reduce biliverdin to become bilirubin and UDP-glucuronyltransferase helps conjugate bilirubin in the step afterwards
Adenine phosphoribosyl transferase catalyzes the transformation of adenine to AMP. **(True/False)**
**True** - this occurs in the purine salvage pathway in which PRPP (5-phosphoribosyl 1-pyrophosphate) gives it’s ribose 5-phosphate to adenine, converting it into AMP.
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Lesch-Nyhan syndrome involves reduced levels of 5-phosphoribosyl-1-pyrophosphate (PRPP). **(True/False)**
**False** - it involves an increased level of PRPP, an increase in purine de novo synthesis, and an increase of uric acid resulting in gouty arthritis, neuropathology, and self mutilation
19
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In pyrimidine nucleotide synthesis, uridine triphosphate converts to uridine monophosphate. **(True/False)**
**False** - It goes from uridine monophosphate gets phosphorylated → uridine triphosphate → cytidine triphosphate.
\ In addition, uridine monophosphate → thymidine triphosphate
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Adenine is a pyrimidine with two rings. **(True/False)**
**False** - adenine is a purine with two rings.
\ Tip: Purines sounds like pure, and babies make GAGA sound and are pure. G - guanine A - adenine = GA, and it’s said twice for two rings (GAGA).
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Heme is the most prevalent metalloporphyrin in the human body. **(True/False)**