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SUM: Med 1 Biochem > Final Exam Practice > Flashcards

Final Exam Practice Flashcards

1
Q

Patient shows brownish-yellow pigmentation off skin and a sclera, causing you to suspect hepatic jaundice if your diagnosis is correct, you might expect to see Hight levels of what compounds

A
  1. Conjugated Bilirubin in blood
  2. Unconjugated bilirubin in blood
  3. Urobilinogen in the blood
  4. Urobilinogen in the urine
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2
Q

Can unconjugated bilirubin be present in the urine?

A

NO

It is not water soluble and therefore cannot excrete in the urine

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3
Q

Is Jaundice caused by conjugated or unconjugated bilirubin

A

Post-Hepatic Jaundice, also called Obstructive Jaundice, is caused by an interruption to the drainage of bile containing Conjugated Bilirubin in the biliary system.
Most common cause are gallstones in the common bile duct and pancreatic cancer in the head of pancreas

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4
Q

What is the fate of Urobilinogen

A

In the intestine is directly reduced to brown Stercobilinogen, which can be further oxidized to stercobilin

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5
Q

Define Gilbert’s Syndrome

A

Genetic Condition- in which liver doesn’t properly process bilirubin.

Gilbert’s syndrome is due to a mutation of the
UGT1A1 gene with results in decrease activity of the Bilirubin Uridine Diphosphate Glucuronosyltransferase enzyme.

High unconjugated bilirubin due to excess red blood cell breakdown, large bruises,

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6
Q

Define Alkaptonuria

A

Rare genetic disorder in which the body cannot process the AA phenylalanine and Tyrosine which occur in Proteins

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7
Q

What accumulates due to Alkaptonuria genetic disorder

A

It is accumulation of intermediate substance known as Homogentisic Acid in the blood and tissues.

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8
Q

What causes Alkaptonuria

A

Mutation in the HGD gene for the enzyme homogentisate 1,2-deoxygenate

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9
Q

Pt presents dark spots in his sclera, black pigmentation on cartilage and collagenous tissue. His urine turns black while standing/exposed to air….you recognize these symptoms to be characteristic of

A

Alkaptonuria Inherited genetic disorder—-recessive condition

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10
Q

Why does the urine turn black in Alkaptonuria disorder

A

The deficiency in homogentisic Acid oxidase…it causes homogentisic aciduria: the urine contains elevated levels of homogentisic acid which is oxidized to a dark pigment while exposed to air

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11
Q

Define Phenylketonuria

A

(PKU)
Inherited disorder increases levels of Phenylalanine due to mutations in the PAH which results in low levels of enzyme Phenylalanien Hydroxylase (PAH)

Additional: Deficiency in conversion fo L-Phenylalanien to L-Tyrosine cause acculation of phenuylalanine

TX- Dietary restrictions (meat, fish,eggs,
PKU-can lead to intellectual disability, seizures, behavior problems and mental disorders

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12
Q

Define Pheochromocytoma

A

A neuroendocrine tumor of the medulla of the Adrenal Gland originating in the Chromaffin cells or extra tissue that failed to involuted after birth that secretes high levels of catecholamines mostly norepinephrine and epinephrine to a lesser extent

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13
Q

Define catecholamines

A

Any group of Sympathomimetic amines ( Dopamine, epinephrine norepinephrine) = act as hormones or neurotransmitters

Amine derived form the AA Tyrosine

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14
Q

Pheochrmocytoma, a tumor of catecholamines secreting cells causing dangerous hypertension in a patient…these hypertansive episodes, you recommend as a best drug that one which inhibits

A

MAO=Monoamine Oxidase
COMT=Catechol-O-methyltransferase

Both catalyze degradation of catecholamines

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15
Q

Define Parkinson’s disease

A

Neurodegenerative movement disorder due to insufficient dopamine production as a result of the idiopathic loss of dopamine-producing cells in the brain.

Administration of L-DOPA (levodopa) is the most common treatment.
Note: Dopamine cannot cross the blood brain barrier .

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16
Q

What does MAO stand for and where can it be found

A

Monoamine Oxidase
Enzyme can be found in liver and intestines

This enzyme oxidatively delaminates and inactivated any excess neurotransmitter molecules that may leak out of synaptic vesicles when the neuron is at rest

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17
Q

In response to B12 deficiency what conditions may develop in the pt if not treated properly

A

Accumulation of branched Fatty acids incorporated into cell membranes including those of CNS- causing neurologic manifestations

Note: deficiency of B12 can be determined by the levels of methylmalonic acid in blood which is elevated in individuals with decreased absorption of the vitamin

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18
Q

Clinical indication of B12 deficiency

A

Pernicious Anemia most common in pt who fail to absorb the vitamin from the intestine

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19
Q

Folic Acid supplementation can partially reverse what

A

hematologic abnormalities do B12 deficiency therefor masking cobalamin deficiency

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20
Q

B 12 Deficiency causes what 3 type of conditions

A

Pernicious Anemia (life long TX)
Megaloblastic anemia
Hypochromic anemia
Lupus

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21
Q

Enzyme abnormalities can lead to Hyperuricemia and Gout include

A

Reduced activity of Hypoxanthine-quinine phosporibosyltransfrease

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22
Q

Define Lesch-Nyhan syndrome

A

Formation of uric asic stones in the kidneys (urolithiasis ) and the deposition of Yates crystals in the points (gout arthritis) and soft tissue.

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23
Q

What is Lesch-Nyhan characterized by

A

Motor dysfunction
Cognitive defects
Behavioral disturbances = self mutilation

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24
Q

What Enzyme deficiency causes Lesh-Nyhan syndrome

A

Hypoxanthine-Guanie phosphoribosyltransferase (HGPRT)

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25
Q

Define Dicarboxylic Academia

A

Elevated methylmalonic Acid In blood are symptoms of Vit B 12 deficiency

Note: Methylmalonic acid = Dicarboxylic acid

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26
Q

Hyperuricemia

A

Elevated uric acid caused by too much of Vit B12

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27
Q

Define Hypochromic Anemia

A

Genetic term for any type of Anemia in which the red blood cells (Erythrocytes) are paler that normal.
(Hyper refers to less & Chromic means Color)

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28
Q

Define Hyperchromia

A
  1. Defined as excessive pigmentation (as of the skin)

2. A state of the red blood cells marked by increase in the hemoglobin content

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29
Q

Define Megaloblastic Anemia

A

Anemia of Macrocytic classification hat result from inhibition of DNA synthesis during Red blood cell production

Note: DNA synthesis is impaired the cell cycle cannot growers from the G2 growth stage to the Mitosis (M) stage= which leads to continuing cell growth without division which presents as Macrocytosis

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30
Q

What tests can be administered to ascertain Vit B12 Def

A

Gold Standard direct measurement of the Blood Cobalamin

A measurement of Methylmalonic Acid Can provide an indirect method for partially differentiating Vit B 12 and Folate deficiencies

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31
Q

Define Chronic Granulomatosus Disease

Recall as much information as possible :)

A

Chronic granulomatous disease (CGD) (also known as Bridges–Good syndrome, chronic granulomatous disorder, and Quie syndrome

[1]) is a diverse group of hereditary diseases in which certain cells of the immune system have difficulty forming the reactive oxygen compounds (most importantly the superoxide radical due to defective phagocyte NADPH oxidase) used to kill certain ingested pathogens.

[2] This leads to the formation of granulomata in many organs

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32
Q

Chronic Granulomatosus

Simplified

A

Disease caused by genetic deficiencies in NADPH Oxidase; characterized by sever, persistent infections and the formation of Granulomatosus (nodule ares of inflammation) that sequester the bacteria

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33
Q

Define Pompe’s Disease

A

Glycogen storage disease type II, also called Pompe disease,

  1. an autosomal recessive metabolic disorder which damages muscle and nerve cells throughout the body.
  2. It is caused by an accumulation of glycogen in the lysosome due to deficiency of the lysosomal acid alpha-glucosidase enzyme.
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34
Q

Type 1 Diabetic has blood glucose of 250mg/dL..after insulin injection blood glucose volume decreases to 150 mg/dL
Which of the following changes in liver metabolism would most likely accompany this disease?

A

Increased Hexokinase Activity

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35
Q

Ornithine Transcabamylase deficiency

A

Orotic Aciduria diagnosis

General Discussion. Ornithine transcarbamylase (OTC) deficiency is a rare X-linked genetic disorder characterized by complete or partial lack of the enzyme ornithine transcarbamylase (OTC).

OTC is one of six enzymes that play a role in the break down and removal of nitrogen the body, a process known as the urea cycle.

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36
Q

What is Ornithine use for

A

L-ornithine is a catalyst in the process that converts ammonia into urea, which can be eliminated through urine.

The liver uses the enzyme arginase and the amino acid L-arginine to synthesize urea and L-ornithine as part of the urea cycle.

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37
Q

Which process/reactions will be the lowest in Pt with uncontrolled diabetes mellitus

A

Pyruvate dehydrogenase reaction

Note: Stimulated Fatty Acid oxidation causes increase in Acetyl-CoA, and this in-turn inhibits Pyruvate dehydrogenase

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38
Q

When acetoacetate synthesis is active

A

Ketone bodies production is stimulated

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39
Q

When Pyruvate Carboxylase reaction occurs

A

Gluconeogenesis is stimulated

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40
Q

Microcytic Hypochromic anemia can result from what factors

A

Dietary deficiency in:

Iron
Pyridoxine
Ascorbate

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41
Q

Elevated Homocysteine & Decreases Folic acid levels in pregnant woman are associated with what?

A

Increased incidence of Neural Tube defects (improper closure=spinal bifida) in the fetus.

Periconceptual supplementation with folate reduces the risk of such defects

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42
Q

Homocysteine Methyltransferase

3 different points

A
  1. (BHMT) is a zinc metallo-enzyme that catalyzes the transfer of a methyl group from trimethylglycine and a hydrogen ion from homocysteine to produce dimethylglycine and methionine respectively
  2. This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases.
  3. This enzyme participates in the metabolism of glycine, serine, threonine and also methionine.
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43
Q

Wen the insulin/glucagon ratio is high, which of the following enzyme activities is true

A

Pyruvate Kinase activity increases and PEP carboxykinase decreases

(PEP)= Phosphoenolpyruvate

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44
Q

What is Phosphoenollpyruvate Carboxykinase responsible for

A

(PEPCK) an enzyme in the lease family used in the metabolic pathway of gluconeogenesis.

It converts oxaloacetate into phoshoenolpyruvate and CO2

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45
Q

Insulin increases/decrease what

A

Increases glycolysis

Decreases gluconeogenesis

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46
Q

Deficiency of which enzyme is likely to account for Hemolytic anemia

A

Pyruvate Kinase

Note: Hemoglobin Oxygen dissociation curve shifts to R (reduced affinity of hemoglobin for oxygen) this is a characteristic for increased 2.3-BPG concentration.

Red blood cells with Pyruvate kinase deficiency produce more of 2,3-BPG as compensatory effect

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47
Q

Analysis of pt serum revealed an elevated VLDl. Which of the following mechanism account for the finding

A

Decreased activity of Lipoprotein lipase

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48
Q

VLDL
IDL
LDL…..what do they stand for

A

VLDL=very low density lipoprotein
Produced more with increased activity of ACAT

IDL=Intermediate density lipoprotein

LDL= Low density Lipoprotein

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49
Q

What happens to cholesterol as its synthesized in the liver

A

It is either converted to bile salts or esterified by ACAT (Acyl CoA: Cholesterol acyltransferase), packed into VLDLs and transported to tissues

Cholesterol in VLDLs is either esterified to LCAT(lecithin-Cholesterol acyltransferase) or exchanged for triacylglycerols form HDLs

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50
Q

Triacylglycerols in VLDLs …what happens

A

Are degraded by lipoprotein lipases.

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51
Q

Define Mycophenolic acid

It is used to prevent graf rejections by depriving lymphocytes of nucleotides via

A

Drug used to prevent graf rejection

Drug is reversible inhibitor of IMP
Drug is immunosuppressant

Inhibition of IMP dehydrogenase
(IMP)=Inosine monophosphate dehydrogenase

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52
Q

14 year old girl has history of Diarrhea and fatty stools. Her serum cholesterol & triacylglycerol levels are extremely low. You recognize her symptoms resulting from which condition

A

Abetalipoproteinemia

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53
Q

Abetalipoproteinemia define

A

Impaired Chylomicrons assembly- dietary triacylglycerols and cholesterol cannot enter bloodstream

is a disorder that interferes with the normal absorption of fat and fat-soluble vitamins from food.

It is caused by a mutation in microsomal triglyceride transfer protein resulting in deficiencies in the apolipoproteins B-48 and B-100, which are used in the synthesis and exportation of chylomicrons and VLDL respectively

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54
Q

Hyperliproproeinemia type III

A

Impaired cholesterol and triglycerides metabolism leading to hyperlipidemia

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55
Q

Lipoprotein lipase deficiency

A

Impaired fatty acid metabolism leading to hypertriglyceridemia

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56
Q

LCAT deficiency

A

Accumulation of unesterified cholesterol

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57
Q

28 old, blood smear reveals large RBC & hypersemented neutrophils. Further analysis reveals a mild homocystinemia. Which of the following enzymes is most likely have abnormal low activity

A

Cystathionine synthase

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58
Q

What is Cystathionine synthase responsible for

A

Conversion of homocysteine to cysteine

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59
Q

A man with history of genetic disease undergoes hip replacement surgery for arthritis. During operation the surgeon notes dark pigmentation in the mans cartilage. His ochronotic arthritis is most likely caused by oxidation and plymerization of excess tissue

A

Homogentisic acid

Condition is Alkaptonuria

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60
Q

Physical examination of a 21 year old mentally retarded man revealed hepatomagaly and spenomagaly. Bone marrow biopsy showed macrophages with “crumpled tissue paper” appearance of the cytoplasm. These symptoms are diagnostic of?

A

Gaucher’s Disease

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61
Q

Define Gauchers Disease

A

(GD)is a genetic disorder in which glucocerebroside (a sphingolipid, also known as glucosylceramide) accumulates in cells and certain organs.

It is caused by a hereditary deficiency of the enzyme glucocerebrosidase (also known as glucosylceramidase), which acts on glucocerebroside. When the enzyme is defective, glucocerebroside accumulates, particularly in white blood cells and especially in macrophages (mononuclear leukocytes).

Gaucher’s disease is the most common of the lysosomal storage diseases.[2] It is a form of sphingolipidosis (a subgroup of lysosomal storage diseases), as it involves dysfunctional metabolism of sphingolipids.[3]

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62
Q

Gaucher’s disease is characterized by

A

The disorder is characterized by bruising, fatigue, anemia, low blood platelet count and enlargement of the liver and spleen

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63
Q

In Guchers disease what accumulates and what is affected by this accumulation

A

Glucocerebroside can collect in the spleen, liver, kidneys, lungs, brain, and bone marrow.
Manifestations may include enlarged spleen and liver, liver malfunction, skeletal disorders or bone lesions that may be painful, severe neurological complications, swelling of lymph nodes and (occasionally) adjacent joints, distended abdomen, a brownish tint to the skin, anemia, low blood platelet count, and yellow fatty deposits on the white of the eye (sclera).

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64
Q

Define hepatomegaly

A

Hepatomegaly is the condition of having an enlarged liver.

It is a non-specific medical sign having many causes, which can broadly be broken down into infection, hepatic tumours, or metabolic disorder.

Often, hepatomegaly will present as an abdominal mass. Depending on the cause, it may sometimes present along with jaundice.[1]

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65
Q

Splenomegaly define

A

Abnormal enlargement of the spleen

66
Q

During bile salt metabolism in the intestine

A

Cholic acid is converted to deoxycholic acid

Intestinal bacteria converts primary bile salts to secondary bile salts.

67
Q

If you suspect a deficiency of folate in the body of your patient, you know it can be a diagnosed by high urinary excretion of ?

A

Formiminoglutamate

Folic acid is involved in histidine catabolism (conversion of histidine to glutamine, with formiminoglutamate as intermediate)

68
Q

Histidine can be converted to what ?

A

Glutamate

With formiminoglutamate as intermediate

69
Q

Acute intermittent porphyria is characterized by what

A

Deficiency of uroporhyrinogen 1 synthase

Accumulation of ALA & porphobilinogen in the patien blood and urine

Toxic effects on the nervous system that cause neuropsychiatric symptoms

Increased synthesis of ALA synthase

70
Q

Acute intermittent porphyria is characterized by all excerpt

A

Cutaneous Photosensitivity

71
Q

In order to increase the reverse transport of cholesterol form peripheral tissue to the liver, you can recommend the drug that ?

A

Stimulates the synthesis of the SR-B1 receptor

Stimulates the expression of the ABCA1 or ABCG1 protein

72
Q

In Salvage reaction for purines

A

Purine nucleotides are formed from purines and phosporibosyl phosporylation
(Should be phosporibosyl pyrophosphate)

73
Q

In salvage reactions for purines: purine nucleotides are? give example and are synthesized form what ?

A

Purine nucleotides (AMP,GMP, IMP) are synthesized from purines from degradation pathway of nucleotides from cellular nuclei acid or food

74
Q

What does the salvage reaction of purines involve?

A

The reactions involves activated ribose-5-phosphate:

5-phosphoribosyl-1-puyrophosphate

75
Q

Nucleoside =

A

Sugar + Base

76
Q

Nucleotide=

A

Sugar + Base + Phosphate

77
Q

The carbons of all amino acids end up in the TCA cycle. Which group of AA has common entry point to the cycle

A

A. Arginine, proline, glutamine
C. Arginine, glutamate, histidine

There were two answers..

Note: Glutamine & Glutamate are inter-convertible, the entry point for Arg, Pro, His, Gln, & Glu is Alpha-ketoglutarate via glutamate

78
Q

A combination of elevated conjugated bilirubin, normal unconjugated bilirubin in the blood and absence of sterocobilin formation in a jaundiced patient suggests what?

A

Bile duct obstruction

79
Q

Gilbert’s syndrome & Criggler-Najjar syndrome are associated with deficiency in what enzyme and show elevation in what type of bilirubin

A

Election in unconjugated bilirubin in the blood

Both associated with bilirubin-UDP glucuronyltransferase deficiency

80
Q

What occurs with Bile duct obstruction

A

Conjugated bilirubin cannot enter the intestine.

Stercobilin is produced in the intestines from urobilinogen (which in turn is from conjugated bilirubin entering via bile duct)

Without sterocobilin the stools are pale in color (Clay color)

81
Q

2 year old is seen by her doctor and is noted to have mental retardation with enlarged liver and spleen. Bone marrow revealed the presence of numerous foam cells. This patient has

A

Neiman-Pick disease

82
Q

Neimann-Pick disease

A

Niemann-Pick disease (NPD) is a group of diseases passed down through families (inherited) in which fatty substances called lipids collect in the cells of the spleen, liver, and brain

83
Q

Neiman-pick disease is considered one with inability to what

A

One of sphinglipidosis (inability of sphingomyelin degradation) liver deposition in liver and spleen (enlargment).

The deposits in cells look “foamy” neurodegeneration

84
Q

Analysis of blood plasma of your infant patient shows turbidity with elevated TG level. A plasma sample has been left in refrigerator over night revealed cream-colored material floating on top. The underlying plasma was clear. Which type or hyperliporoteinemia is most likely present in this patien?

A

Type 1

85
Q

In Type 1 Hyperlipoproteinemia is defined by what deficiency

A

Lipoptotein lipase deficiency: triglycerides (TG) from chylomicrons and cannot be degraded.
After separation of fat, plasma is clear because only chylomicrons are increased (other lipoproteins are in norm)

86
Q

In glucose tolerance test, an individual is given to drink large amount of glucose. If the individual is normal, ‘tis ingestion should result in what?

A

An enhanced activity of Acetyl-CoA Carboxylase

87
Q

Indicate which components contribute to the purine ring

A

Tetrahydrofolate contributes atom 7 of purine

Glutamine: Atom 1 & 4
Glycine: Atom 2
CO2: Atom 5
Aspartate: Atom 6
Formyltetrahydropholate: 
Atom 3 & 7 (purine)=cyclohexane
88
Q

Which combination of amino acids if removed from the diet of an adult would result in negative nitrogen balance

A

Phenylalanine, alanine, serine

Negative nitrogen balance: lack of essential amino acids in diet.

89
Q

Name all essential AA

Define essential acid

A

Essential means, body cannot produce therefore need to be provided in the dietary intake

Essential AA:

1- histidine
2-leucine
3-isoleucine 
4-lysine
5-methionine
6-phenylalanine
7-tryptophan
8-threonine
9-Valine
90
Q

Acetyl-CoA Carboxylase is responsible for what

A

Acetyl CoA carboxylase plays an essential role in regulating fatty acid synthesis and degradation

The carboxylase is controlled by three global signals—glucagon, epinephrine, and insulin—that correspond to the overall energy status of the organism. Insulin stimulates fatty acid synthesis by activating the carboxylase, whereas glucagon and epinephrine have the reverse effect.

91
Q

You found elevated levels of phenylalanie and phenylpyruvate in the blood of a new born infant. Which of the following enzymes you suppose to be deficient in this baby

A

Dihydrobiopterin reductase

92
Q

What happens in Phenylketonuria

A

Blocked transformation of phenylalanine to tyrosine.

The deficiency of phenylalanine Hydroxylase which is dependent on dihydrobiopterin reductase

Phenylalanine and phenylpyruvate accumulate in the blood and tissues

93
Q

If your patient reveals methylmalonic Acidemia, you know immediately that a defect is his/her metabolism is cause by

A

Deficiency in B12 (cobalamin)

94
Q

Heinz bodies are histological hallmark of what disorder

A

Glucose-6-Phospate dehydrogenase deficiency

95
Q

What are he is bodies

A

Precipitated dentaurated hemoglobin in RBC

96
Q

G6PD stands for what and deficiency of it leads to what

A

Glucose 6-phosphate dehydrogenase

G6PD deficiency leads to increased oxidation (less NADH and reduced glutathione) which causes hemoglobin denaturation

97
Q

Which of the following enzymes is believed to be most responsible foe the development of cataracts in individual with diabetes mellitus

A

Aldo’s reductase

98
Q

Failure of normal DNA synthesis in the lymphocytes of a patient with SCID is a result of inhibition of which of the following enzymes fo purine nucleotide metabolism

A

Ribonucleotide reductase

99
Q

What does SCID stand for and define it

A

Sever Combined immunodeficiency

Deficit of adenosine deaminase causing accumulation of deoxyadensine.

Deoxyadenosine inhibits ribonucleotide reductase.

Ribonucleotide reductase is crucial for DNA synthesis: it converts ribonucleotide to deoxyribonucleotides (for DNA synthesis the deoxy-form is requred)

When deoxyadenosine accumulates, the other deoxyribonucleotides cannot be produced and DNA synthesis stops

100
Q

Which of the following lis characteristic of low insulin level

A

Decreased activity of lipoprotein lipase

Note: insulin stimulates lipoprotein lipase in adypocytes
When insulin is low (in fasting) lipoprotein lipase activity in adipose tissue is low to prevent adipose tissue from taking up and storing circulating triacylglycerols

101
Q

Write on paper:

If insulin is low ………………..is low and gluconeogenesis is …………………

If insulin’s is low ……………..is low and ……………..3-…………………..(…………)

If insulin is low ………….is low, decreased …………… ………….( in ………………..)

Insulin stimulates synthesis of what ?

A

Glucose is low
Increased gluconeogenesis

Glucose is low
Increased 3-hydeoxybutyrate (ketone body)

Glucose is low
Pyruvate dehydrogenase (in Glycolysis)

Synthesis of cholesterol

102
Q

Diagnosis of Adrenal Pheochromocytoma or choleserohrmacytomas is based on the urinary excretion of

A

Vanillylmandelic acid derived from epinephrine and norepinephrine (VMA)

103
Q

Homovanillic acid derives from what

A

Dopamine

104
Q

A person whose sole protein source is corn may be deficient in which AA

A

Tryptophan & lysine

Note: also leading to nicotinamide (niacin) deficiency (pellagra)

105
Q

Cholestyramine exerts its hypocholesterolemic effect by interacting with

A

Bile Acids

106
Q

What is Cholestyramine

A

Bile acid sequestration
It binds bile salts in the intestines to prevent them to reabsorb and promote their excretion.
Removal of bile salts relieves the inhibition on bile acid synthesis in the liver

107
Q

Markedly reduced levels of cholesterol esters in blood lipoproteins results from a deficiency of

A

Lecithin: Cholesterol acyltransferase (LCAT)

Note: deficiency will case accumulation of non-esterified cholesterol in blood (high plasma unesterified cholesterol and low plasma cholesterol ester)

108
Q

The circulating form of hemoglobin that is used to assess blood glucose concentration in diabetes mellitus is

A

Hemoglobin A1

Hemoglobin A1 is nonenzymaticaly glycosylated (glycated) and extent of glycosylation depends on glucose plasma concentration

109
Q

Which of the following genetic disorders is due to a defect in lysosomal metabolism

A

Hurlers disease

110
Q

Ehlers-Danlose syndrome is

A

Genetic connective tissue disorder

111
Q

Von Gierke imperfecta is

A

Glycogen storage disease

Glucose 6-Phosphatase deficiency

112
Q

Osteogenesis Imperfecta

A

Bone fragility, collagen gene mutation

113
Q

Andersen’s disease

A

Glycogen storage disease

114
Q

OXPHOS disease

A

Oxidative phosphorylation disease

This disease impacts tissues with the highest energy demand (brain, nerves, retina, skeletal and cardiac muscle)

115
Q

Which of the following enzymes is regulated by reversible covalent modification

A

Pyruvate dehydrogenase

Note: 
Phosporylated PDH (inactive)
Dephosphorylated PDH (active)
116
Q

Person with insulin dependent diabetes mellitus failed to take insulin regularly and was found to have high VLDL and as a consequence, which of the following compounds in the blood would be elevated

A

Triacylglycerols

117
Q

All of the following increase the extent of sickling in sickle cell anemia patients by increasing the proportion of deoxygenated hemoglobin S except

A

Increased carbon monoxide

Increased ph

118
Q

What enzyme is responsible to leukotriene production

A

Arachidonate 5-lipoxigenese

119
Q

Define leukitriene

A

Family of eicosanoid inflammatory mediators produced in leukocytes by the oxidation of arachnoid acid (AA) and the essential fatty acid eicosapentaenoic acid (EPA) by the enzyme arachidonate 5-lipoxygenase

120
Q

Leukotriene are responsible for

A

any of a group of compounds derived from unsaturated fatty acids, primarily arachidonic acid, that are extremely potent mediators of immediate hypersensitivity reactions and inflammation, producing smooth muscle contraction, especially bronchoconstriction, increased vascular permeability, and migration of leukocytes to areas of inflammation.

121
Q

Disease characterized by increased leukotriense synthesis is

A

Asthma

122
Q

Can asthma be treated with Aspirin

A

NO!
Because it is part of (NSAIDs)
Notsteroidal anti-inflammatory drugs

123
Q

What are NSAIDS

A

Nonsteroidal anti-inflammatory drugs

-drug class that reduce pain, decrease fever, prevent blood clots and, in higher doses, decrease inflammation

It’s action=enzyme inhibitor

124
Q

What are some examples of NSAID

A

Aspirin
Ibuprofen (Motrin, Advil)
Naproxen (Aleve, Anaprox DS, Naprosyn)

Indomethacin (Indocin)
Phenylbutazone
Celebrex

125
Q

Disease characterized by increase of leukotriene synthesis is ……….and it should be treated with ?

A

Asthma

Treated with Inhibitors of 5-Lipoxygenase and antagonists of leukotriene receptors

Pg 214

126
Q

What enzyme is deficient in hereditary fructose intolerance

A

Aldolase B

Pg 138

127
Q

In the hereditary fructose intolerance.. what metabolites accumulate and what are the symptoms of the disease?

A

Fructose 1-Phosphate accumulates
ATP falls and AMP rises= Hyperuricemia, lactic acidosis, hypoglycemia, impaired protein synthesis (example..decrease in blood clotting factors) impaired glycogenolysis.

Diagnosis: Fructose in urine

P 138

128
Q

Respiratory distress syndrome is seen most frequently in ………………and is caused by

A

Premature Infants

Cause by insufficient production of pulmonary/lung surfactants

P 204

129
Q

Malignant carcinoid tumor is associated with increase synthesis of ?

A

Vasoactive hormones (primarily Serotonin)

130
Q

What are the two primary functions of thiamine.

A

Formation or degradation of
Alpha -ketone by (transketolase) and in the oxidative decarboxylation of Alpha-ketone Acid (Pyruvate dehydrogenase complex, alpha-ketoglutarate dehydrogenase complex)

P379

131
Q

What is Nitrogen balance

A

It is when the amount of nitrogen consumed equals that of the nitrogen excreted in the urine (primarily as urinary urea nitrogen UUN)

P367

132
Q

Where are HDLs formed and what is their function

A

HDL particles are formed in blood by addition of lipid to apo A-1 and apolipoprotein made within the liver and intestine is secreted into blood.

Function to keep lipids (primarily triacylglycerols (TAG) and Cholesteryl esters) soluble as they transport them between tissues.

Responsible for Uptake fo unesterified Cholesterol & esterification of cholesterol and reverse cholesterol transport

P 234-236

133
Q

Faulty collagen synthesis is resulting form inherited defects caused by several disease. List some of them that you learned.

A

Ehlers-Danlos syndrome
Osteogenesis imperfecta

P48-49

134
Q

Name 5 amino acids that are essential for humans

A 
Leucine
Isoleucine
Tryptophan
Threonine
Methionine 
Valine 
Histidine
Phenylalanie

P262

135
Q

The predominant nitrogen metabolite excreted in urine in humans.

A

Urea

P253

136
Q

What proteins serve as the primer of glycogen synthesis

A

Fragment of existing glycogen or glycogenin (if glycogen is absent)

Pt 126-127

Note: fragment of glycogen can serve as a primer in cells whose glycogen stores are not totally depleated..in absence of glycogen, protein glycogenin can serve as a acceptor of glucose residues form UDP-glucose

137
Q

Name 3 major apolipoproteins and list their functions

A

Apo A-1: major apolipoprotein
Of HDL-activates LCAT

Apo-100: apolipoprotein of VLDL, IDL, LDL
Apo-100 is recognized by receptors of endocytosis

Apo C-II: Activates lipoprotein lipase in capillaries (transferred form circulating HDLs to other lipoproteins)

Apo E: liver cells have receptor Apo E- lipoproteins can be endocytosed degraded in lysosomes (Apo E transferred from circulating HDL to other lipoproteins: chylomicron remnants, IDLs)

138
Q

In fasting what molecule allosterically stimulates glycogen breakdown in muscle?

A

AMP (Adenonine Monophosphate) - (allosteric activator of glycogen phosphorylase)

P134

139
Q

Name glycogen storage diseases type 1

A

von Gierke disease

140
Q

What is the enzyme deficiency in Glycogen storage disease 1 (von Gierke disease)

A

Enzyme deficiency is Glucose 6-Phosphate

141
Q

What are the symptoms of Von Gierke disease

A 
Severe fasting hypoglycemia
Fatty liver
Hepato & amp; renomegaly 
Progressive renal disease
Growth retardation 
Delayed puberty
Lactic Acidemia
Hyperlipidemia 
Hyperuricemia

P130

142
Q

What sets follow glutamate formation during amino acid catabolism

A

Oxidative glutamate deamination in which the A group is liberated as free ammonia (catalyzed by glutamate dehydrogenase)

P252

143
Q

Pellagra is a disease which results form a deficiency of

A

Niacin ( Vit B3)

144
Q

What clinical features are associated with Pellagra

A

Three D’s:

Dermitis
Diarrhea
Dementia

P380

145
Q

Statins are drugs used in treatment

A

Treatment of hypercholesterolemia

146
Q

What is the mechanism of action of Statins

tx: hypercholesterolemia

A

They inhibit cholesterol synthesis
(Reversible competitive inhibitors of HMG CoA reductase)
(Hydroxy 3-Methyl-glutaryl)
P224

147
Q

Cellular cAMP levels can be increased by inhibiting what enzyme?

A

cAMP phosphodiesterase
(Cyclic Adenosine monophosphate)

P95-96

148
Q

What enzyme liberates arachidonic acid from the plasma membrane?

A

Phospholipase A2

P207

149
Q

What is Glycogen storage disease type V

A

McArdle Syndrome

150
Q

What is the main organ and enzyme affected in this Glycogen storage disease type V
(McArdle syndrome)

A

Skeletal muscle,
The enzyme affected is glycogen phosphorylase (or myophosphorylase)

P 129

151
Q

By what mechanism does oligomyocin poison oxidative phosphorylation?

A

Oligomycin - antibiotic which inhibits the ATP synthase by closing its proton channel, which is necessary for oxidative phosphorylation of ADP to ATP and preventing proton re-entry into mitochondrial matrix…
Note: the inhibition of ATP synthesis would also stop electron Transport chain

P78

152
Q

Allopurinal is used to inhibit what enzyme

A

Xanthine oxidase

Allopurinal (drug used to decrease High blood uric acid levels)
Used to prevent Gout, kidney stones)

153
Q

Allopurinal is used to inhibit the enzyme Xanthine oxidase…. what is the action of this enzyme

A

Xanthine oxidase catalysts the oxidation of Hypoxanthine to Xanthine and oxidation of Xanthine to uric acid (part of degradation of purine nucleotides)

154
Q

Classical galactosemia is caused by inherited deficiency of what enzyme

A

Galactose-1-phosphate uridylyltransferase

155
Q

What toxic metabolites are responsible for the clinical manifestations of Classical galactosemia

A

Galactitol
Galactose-1-phosphate

P141

156
Q

Pyruvate dehydrogenase is inhibited by

A

NADH & AMP; acetyl CoA

157
Q

What does pyruvate dehydrogenase require

A

Thiamine pyrophosphate (TPP)

Thiamine (Vit B1)

158
Q

Pyruvate Carboxylase is activated by

A

Acetyl CoA

159
Q

What does Pyruvate Carboxylase require

A

Biotin (Vit B7)

160
Q

What does Alanine aminotransferase require

A

pyridoxal phosphate (active form of Vit B6)

If your liver is damaged it will release more ALT=alanine aminotransferase into your body
Elevated liver enzymes

161
Q

What is phosphorylated and inactivated by protein kinase

A

Pyruvate kinase

162
Q

What forms products when NADH levels are elevated

A

Lactate dehydrogenase (LDH)

LDH=catalyze the conversion of lactate to pyruvic acid and back, as it converts NAD+ to NADH and back

SUM: Med 1 Biochem (12 decks)

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