Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/331

Click to flip

331 Cards in this Set

  • Front
  • Back
What are the fat soluble vitamins?
A,D,E,K
The absorption of fat soluble vitamins depends on what two organs?
small intestine (ileum) and pancreas
Is toxicity more common for fat or water soluble vitamins?
fat soluble becauase the vitamins accumulate in the fat
What can cause fat-soluble vitamin deficiencies besides just general lack of intake?
malabsorption syndromes and mineral oil intake
What are the water soluble vitamins?
B1, 2, 3, 5, 6, 12, C, Biotin, Folate
What do B complex deficiencies cause?
dermatitis, glossitis, and diarrhea
What is the function of vitamin A?
constituent of visual pigments
Match up the appropriate vitamin with these alternates names? A.thiamine, B.riboflavin, C.niacin, D.retinol,
Thiamine-B1
Riboflavin-B2
Niacin-B3
Retinol-Vit A
What does a deficiency of vitamin A cause?
night blindness and dry skin
What does a deficiency of vitamin B1 cause?
Beriberi and Wernicke-Korsakoff syndrome
What is the function of vitamin B1?
Cofactor for oxidative decarboxylation of alpha-keto acids and a transketolase in the HMP shunt.
Beriberi is characterized by what symptoms?
Dry: polyneuritis, muscle wasting
Wet: High output cardiac failure(dialated cardiomyopathy),edema
What does a deficiency of vitamin B2 cause?
angular stomatitis, cheilosis, corneal vascularization
What is the function of vitamin B2?
cofactor in oxidation and reduction
What is vitamin B3 a constituent of?
NAD+, NADP+
What does a deficiency of vitamin B3 cause?
Pellagra
What are the symptoms of pellagra?
Diarrhea, Dermatitis, Dementia
What is vitamin B5 a constituent of?
Co-A
A deficiency in vitamin B5 causes what 4 problems?
dermatitis, enteritis, alopecia, adrenal insufficiency
When vitamin B6 is converted to ___, it is a cofactor in what three processes?
pyridoxal phosphate; cofactor in transamination, decarboxylation, and trans-sulfuration
What may induce a deficiency in vitamin B6?
INH and oral contraceptives
Biotin is a cofactor in which 3 carboxylations?
pyruvate to oxaloacetate, acetyl-CoA to malonyl CoA, and proprionyl-CoA to methylmalonylCoA
The use of __ and ingestion of __ cause a deficiency in biotin?
antibiotics; raw eggs
What is the most common vitamin deficiency in the US?
folic acid
Neurologic symptoms with anemia are seen in folic acid or B12 deficiency?
B12
What is folic acid important in the synthesis of?
Nitrogenous bases in DNA and RNA
What two drugs are PABA analogues (the precursor of folic acid in bacteria)?
sulfa drugs and dapsone
Vitamin B12 is involved in which two conversions?
Homocysteine to Methionine and Metholmalonyl CoA to SuccinylCoA
Where is vitamin B12 stored
liver
What are the 3 main causes of vitamin B12 defiiciency?
malabsorption, lack of intrinsic factor, and absence of terminal ileum
What test is used to determine a deficiency of vitamin B12
Schilling
Deficiency of Vit C causes what?
Scurvy
Vit C is necessary for ________ of proline and lysine in ________ synthesis
hydroxylation / collagen
Vit C also facilitates absorption of what?
Iron - by keeping iron in Fe2+ reduced state
Vit C is necessary as a cofactor for what?
Dopamine --> NE
What are the clinical findings of scurvy?
Swollen Gums, bruising, anemia, poor wound healing
D2, also called _______ is consumed from what?
ergocalciferol, comsumed in milk
Cholecalciferol, also called ____ is formed where?
D3, formed in sun-exposed skin
25-OH D3 is what form of Vit D
Storage form
1,25 (OH)2D3 is what form of Vit D
Active form
Deficiency of Vit D in children causes? In adults?
Children - Rickets // Adults - Osteomalacia. Also can cause hypocalcemic tetany
Vit D functions to
Increase intestinal absorption of calcium and phosphate
Too Much Vitamin D has three clinical effects. What are they?
Hypercalcemia, loss of appetite, stupor.
The 6 causes of hypercalcemia are:
Vit D. Intoxication / Malignancy / Hyperparathyroidism / Milk-Alkali syndrome / Sarcoidosis / Paget's disease of bone
Excess Vit D is seen in what disease state?
Sarcoidosis - where epithelial macrophages convert vit D into its active form ; and page'ts
Deficiency in Vit E causes?
Increased fragility of erythrocytes (E is for erythrocytes)
Vit E functions as an ______ to protect _______
Antioxidant, to protect erythrocytes from hemolysis
T/F - Vitamin K deficiency causes neonatal thrombi and pulmonary emboli.
False - Vit K deficiency causes - neonatal hemorrhage
How does Vit K effect the PT, aPTT and Bleeding time?
Increased PT and aPTT but normal bleeding time.
What coagulation factors require Vitamin K?
Factors II, VII, IX, X and protein C and S. (remember 1972).
How does warfarin work?
It is a vitamin K antagonist.
What does Vit K catalyze?
The gamma-carboxylation of glutamic acid residues on various proteins concerned with blood clotting.
Where is Vit K synthesized?
Vit K is synthesized by the normal intestinal flora.
What are the two enzymes required to convert Ethanol --> acetaldehyde --> acetate?
Alcohol dehydrogenase for the first reaction, and acetaldehyde dehydrogenase for the second.
What is the limiting reagent in the above reaction?
NAD+ is the limiting reagent for both reactions
How does Disulfiram work?
Disulfiram (antabuse) - inhibits acetaldehyde dehydrogenase (acetaldehyde accumulates, contributing to hangover symptoms)
When I go out drinking with the class of 2006, why is PBL so painful the next morning?
Because acetaldehyde accumulates in my system, and after 2 years, PBL is always painful.
How does ethanol metabolism lead to hypoglycemia?
Ethanol metabolism increases NADH/NAD+ ratio in the liver, causing diversion of pyruvate to lactate and OAA to malate, thereby inhibiting gluconeogenesis and leading to hypoglycemia.
What is hepatocellular steatosis, and how does it occur?
Hepatocellular steatosis = hepatic fatty change… It occurs because of the above pathway resulting in an increase in NADH/NAD+ ratio, which causes a shunting away from glycolysis and toward fatty acid synthesis.
What is kwashiorkor?
Protein malnutrition resulting in skin lesions, edema, liver malfunction (fatty change).
What is marasmus?
protein - calorie malnutrition resulting in tissue wasting.
The clinical picture of a small child with a swollen belly is characteristic of kwashiorkor or marasmus?
Kwashiorkor
Kawashiorkor results from a protein-deficient M.E.A.L. What does M.E.A.L. stand for?
Malabsorption, Edema, Anemia, Liver (fatty)
Glucose is first converted to what in the cell?
Glucose-6-phosphate
What are the three products that glucose-6-phosphate is converted to in the cell?
Glucose-1-P (to glycogen pathway) // Fructose-6-P (To TCA) // 6-phosphogluconolactone (to Ribose-5 phosphate pathway)
What are the steps of the TCA?
Acetyl-CoA --> Citrate --> Isocitrate --> alpha-ketoglutarate --> Succinyl-CoA --> Succinate --> Fumarate --> Malate --> Oxaloacetate
What are the steps of the Urea Cycle?
Aspartate --> Arginosuccinate --> Arginine --> Ornithine --> Citrulline --> Arginosuccinate
Odd chain fatty acids enter the TCA through what series of molecules?
Odd chain FA --> Propionyl-CoA --> Methylmalonyl-CoA --> Succinyl-CoA… into TCA
Acetyl Co-A, aside from entering the TCA, can be converted into what three molecules?
Mevalonic acid, Acetoacetyl-CoA, malonyl-CoA
Beta - hydroxybutyrate is formed from Acetyl-CoA through what precursors?
Acetyl-CoA --> Acetoacetyl-CoA --> Acetoacetate --> Beta-hydroxybutyrate
Cholesterol is formed from acetyl co-A through what precursors?
Acetyl-CoA --> Mevalonic Acid --> Isoprene --> Squalene --> Lanosterol --> Cholesterol
The conversion of Arginine to Ornithine creates as a byproduct, what?
H20 --> Urea
NH4 + CO2, leads to _______, and enters the Urea cycle where?
Leads to Carbamoyl Phosphate, enters at the conversion of ornithine --> citrulline
Write the steps of conversion of glucose to acetyl-CoA
Glucose --> Glucose -6-P --> Fructose-6-P --> fructose-1,6-bisphosphate --> glyceraldehyde-3P --> 1,3-bis-phosphoglycerate --> 3-phosphoglycerate --> 2-phosphoglycerate --> phosphoenolpyruvate --> pyruvate --> acetyl-coA
what are the units comprising ATP
adenine base; ribose sugar; 3 phosphoryls
what type of high energy bonds does ATP have
2 phosphoanhydride bonds, 7 kcal/mol each
how many ATPs are produced in aerobic glucose metabolism?
38 via malate shuttle; 36 via G3P shuttle
what is the active carrier of acyl
coenzyme A, lipoamide
what is the active carrier of 1-C units
THF
what is the active carrier of methyl groups
SAM
what is the active carrier of aldehydes
TPP
what is the active carrier of glucose
UDP-glucose
what is the active carrier of choline
CDP-choline
what are the 2 components of SAM
ATP + methionine SAM = s-adenosyl methionine
what vitamin is SAM dependent on for regeneration
B-12 (regenerates met)
what is the function of SAM
transfer methyl units ("SAM, the methyl donor man")
what enzyme converts glutamate --> GABA
glutamate decarboxylase (with vit B 6)
what enzyme converts choline --> ACh
choline acetyltransferase (ChAT)
what enzyme converts 1,3-BPG --> 2,3-BPG
bisphosphoglycerate mutase
what is used in catabolic processes to carry reducing equivalents
NAD+ (--> NADH) or FAD? I would think.
NADPH is used in (name 3)
1. anabolic process (supply reducing equivalents); 2. respiratory burst; 3. P-450
the HMP shunt and the malate dehydrogenase reaction produce_____
NADPH
the affinity (Km) and capacity (Vm) of glucokinase (compared to hexokinase) is
lower affinity (higher Km) and higher capacity (higher Vmax)
what is the irreversible enzyme and the regulator of the reaction: D-glucose ---> Glucose-6-phosphate
hexokinase (glucokinase in the liver);hexokinase is negatively regulated by G6P
what is the irreversible enzyme and the regulator of the reaction: fructose-6-P ---> fructose-1,6-BP
phosphofructokinase (rate limiting step of glycolysis); up-regulated by AMP, fructose-2,6-BP; down-regulated by ATP, citrate
what is the irreversible enzyme and the regulator of the reaction: PEP ---> pyruvate
pyruvate kinase; up regulated by fructose-1,6-BP; down-regulated by ATP, alanine
what is the irreversible enzyme and the regulator of the reaction: pyruvate ---> acetyl-CoA
pyruvate dehydrogenase. Down-regulated by ATP, NADH, acetyl CoA
what are the 7 glycolytic enzyme deficiencies associated with hemolytic anemia
hexokinase, glucose phosphate isomerase, aldolase, triosephosphate isomerase, phosphate glycerate kinase, enolase, pyruvate kinase
with regard to pyruvate dehydrogenase complex (4 q's): it contains 3 enzymes. What are the 5 cofactors it requires?
the first 4 B vitamins +lipoic acid [B1(thiamine, TPP); B2 (FAD); B3 (NAD); B5(pantothenate-->acetyl CoA) ]
what is another complex that works in a similar way
alpha ketoglutarate dehydrogenase converts "" to succinyl co a
what is the reaction it catalyzes
pyruvate + NAD + CoASH ---> acetyl-CoA + CO2 + NADH
how does exercise activate this reaction?
increases the following nadh->nad+ , adp, and ca++
with regard to pyruvate dehydrogenase deficiency (3 questions: lactic acidosis in this condition is due to backup of _____
alanine and pyruvate (can be seen in alcoholics due to b1 def)
what is the Tx for this condition
intake of ketogenic nutrients (high fat content)
what is one of the most important findings associated with this condition
neurological defects
Pyruvate can be metabolized into four compounds. Name them.
Lactate, Acetyl-coA, Oxaloacetate, and Alanine - remember, if you Love pyruvate, you'l be AOA.
When is pyruvate generated?
Anaerobic metabolism, mainly in muscles. Remember - lactic acid makes muscles sore.
What role does Alanine play in transport?
Alanine carries nitrogen groups from muscles to liver.
How many ATP equivilnets are needed to make glucose from pyruvate?
6
Where is Oxaloacetate used?
Oxaloacetate and Acetyl-CoA are both elements of the TCA cycle. Oxaloacetate can alos be used in gluconeogenesis
How many ATP equivilents does ti take to turn Pyruvate into Alanine?
Trick question. None. Alanine is the only pyruvate product that does not require energy.
What is the Cori cycle?
The process that gets lactic acid from cells who burn glucose anaerobically to the liver, where gluconeogenesis is preformed to send glucose back to those cells.
What two types of tissue produce lactate most frequently?
Muscles working anaerobically, and RBCs (no mitochondria)
How many ATPs do cells get burning glucose to pyruvate?
2
How may ATP does it take to get glucose from pyruvate in the liver?
6
Given that you lose 4 ATP in each cycle, why is this a useful process?
Allows muscles to continue to function anaerobically if you need to and are low on blood glucose.
Name the molcules in the TCA cycle.
Citrate, Isocitrate, Alpha-Ketogluterate, Succinyl CoA, Succinate, Fumerate, Malate, Oxaloacetate.
How to remember this?
Can I Keep Selling Sex For Money Officer?
What is the net gain of ATP?
12 per cycle of the TCA, so 24 per glucose
What things are formed per pyruvate?
3 NADH, 1FADH2, 2CO2, 1GTP
How is this cycle regulated?
unless there is suficient ADP it will not run
Which enzyme complex in the cycle requires co-factors?
The Alpha-ketogluterate dehydrogenase complex.
What factors does it require?
5 - the same ones that are required by the pyruvate dehyrodgenase complex
Which are….?
B1 (thiamine), B2 (riboflavin, FAD), B3 (Niacin, NAD), B5 (pantothenate) and Lipopoic acid
What does the electron transport chain do?
The ETC carries high energy electrons from NADH and FADH2 to oxegen
How does this generate ATP?
Each cytochrome complex pumps H+ into the intermembrane space. ATP generation is coupled to the H+ gradient
What is the effect of ETC inhibitors?
By stopping the ETC they cuase the loss of the H+ gradient, which stops ATP syntesis
Name four ETC inhibitors.
Cyanide, Anitmycin A, rotenone, and CO
What is the effect of ATPase inhibitors?
By stopping the enzyme that uses the H+ gradient to produce ATP, the H+ gradient increases and the ETC stops.
Name one.
Oligomycin
What are the effects of uncoupling agents?
They increase membrnae permeabliity, so you lose the H+ gradient, so the ETC works harder, and you use more oxegen, wihtout making more ATP.
What are the clinical comsequences of this?
Since the by-product of the ETC chain is heat, when the ETC is uncoupled and therefore unregulated, you get excess heat production and fever.
What common drug overdose causes this?
Asprin and other salycilates
What is gluconeognesis?
Since glycolysis is a very energetically favorable reaction, special enxymes are required to get over the energy hump and make glucose from pyruvate.
How many enzymes are unique to this reaction?
4. The other 7 enzymes are the same ones used in glycolysis
What are the four unique enzymes?
Pyruvate Carboxylase, PEP Carboxykinase (oaa->pep), Fructose-1-6-bisphosphanate(GIVES F6P), and Glucose-6-phospahte(gives glucose), Remember: Pathway Produces Fresch Glucose.
What does Pyruvate Carboxylase do?
Pyruvale into oxaloacetate
Where does this reaction take place?
In the mitochondria. Remember, this is where the pyruvate is, asince otherwise it would eb going into the TCA cycle
What happens next?
Oxaloacetate is turned into malate, which is transferied into the cytosol
Why is this imporntat?
If gluconeogneeis and glycolysis happened int eh same space, they would cancel each other out.
Where does the rest of the cycle take place?
In the cytosol
What tissues have these enzymes?
liver, kidney, and intestinal epithlium.
What happens if you lack one of these?
Hypoglycemia if you do not eat frequently
Give an example.
Von Gierke's Disease (lack of Glucose-6-phosphatase)
Is any ATP produced or consumed in this?
No
Is it reverisble?
Yes. The direction of flwo is controled by the metablic needs of the cell.
What does this pathway produce?
Ribose-5-P for nucliotides synthesis and NADPH for RBC metabolism and fatty acid production
Where does it take place?
In the cytosol.
What tissues have this pathway?
Places that make fatty acids or seteroids, so liver, mammary tissue, and adrenal cortex, as well as RBC
G6PD is part of what pathway?
It is the rate limiting step in the PPP (aka HMP) shunt.
What molecule is decreased if this enzyme is inactive?
NADPH
Why is this a problem?
NADPH is necissary to reduce glutathione, which is vital in detoxification of free radicles and oxidizing agents.
What cells are most sensitive to this kind o damage?
RBCs
What kind of disease is caused by a lack of G6PD?
Hemolytic anemai, triggered by oxidative stress.
What consititues oxidative stress?
TB drugs, Fava beans, sulfonamides
How is this disorder passed on?
X- linked recessive.
Where is this prevelent?
Black and mediteranean populations
Histoligically, what will be seen?
Heinz bodies (clumped hemoglobin)
Fructose is central in what pathways in the liver?
Fructose is found in the glycolysis and gluconeognesis pathway.
What is the first step in putting fructose into each of these pathways?
Aldolase B splits fructose-1-P ito Glyceraldehye-3-P
Therefore, a metabloic problem in fructokinase the aldolase will cuse whqat disorder?
Fructose will accumulate, and spill into the urine
What is this called?
essential fructosuira
What is the enzyme involved?
frucokinase (puts a P on fructose)
Is this a dangerous disorder?
no, it is benign, you just have high levels of fructose in your blood and urine. Asymptomatic.
What will happen if Aldolase B is impaired?
Fructose-1-P will build up in the liver
Is this a problem?
Yes. Phophate is used up, and glycogenolysis and gluconeogensis are both impaired.
What are the symptoms?
Hypoglycemia, jaundice and cirrosis.
What is the treatment?
Decrease fructose and sucrose intake
What is the naem of this disorder?
Fructose intolerence
What two steps does Galactose have to go through to enter glycolysis?
Glactokinase turns galactose into galactose-1-P, and then Galactose-1-P uridyl transferase turns that into glucose-1-P
If galactokinase is imparied, what happens?
Galactose builds up in the blood and spills in the urine, but there is no build up of the toxic compound galactose-1-P
Is this dangerous?
No
What happens if Galactose-1-P uridyl tranferase is impaired
Glactose builds up int eh blood, and spills into the urine. There is a build up of the toxic metabolite glactose-1-P
What is this disease called?
Galactosemia
Is is dangerous?
Yes
What are the symptoms?
cataracts, hepatoslenomegaly, and mental retardation
What is the treatement?
reduceing galactose in diet
How do you do this?
Galactose comes from lactose, so limit dairy
Where is lactase normally found?
intestinal brush border
Therefore, if it is missing, what is the main symptom?
gas, bloating, and osmitic diarrhea
Is this common?
Yes.
More in what populations?
Asians and black more than europeans
What is a neumonic for the essential amino acids?
PriVaTe TIM HALL - Phe, Val, Trp, Thr, Ile, Met, His, Arg, Leu and Lys.
Which amino acids are purely ketogenic?
Leu and Lys
Which amino acids are purely both ketogeneic and glucogenic?
Isoleucine, phenylalanine, and tryptophan
What a.a.'s are purely glucogenic?
Anything that is not one of the five above.
Wath two amino acids are essential during growht, but not he rest of the time?
Arg and His
What two a.a.'s are acidic and negativly charged at body pH?
Asp (asparatic acid) and Glu (glutamic acid)
What two a.a.'s are basic and positivly charged at body pH?
Arginine and Lysine (rememebr they are th two with NH3 groups.
How does the body use the positive charge on Arg and Lys?
Histones, which bind to negativly charged DAN are high in these a.a.
Whay does your body produce amonium?
It comes from the NH3 group of amino acids which are being broken down
Where does this happen?
Everywhere in the body
What is the enzyme that transfers the NH3 group
Amino transferases (ex:AST (asparatate amino trnasferase), ALT (alanine amino transferase)
what vitamin is necessary for this?
b6
What two molecules is NH3 transferred between?
It moves from an amino acid to alpha=ketogluterate, making it glutamate.
Is this reaction reversible?
Yes. Glutamate functions as a resevoir, so NH# can be made into urea, or is can give NH3s for a.a. production
Where are these enzymes found?
Inside the cells, so if they are in the blood that is a sign of tissue damage (most in liver and muscle)
Once the NH3 has been added to alpha-ketoglutamate and you have glutamate, what are two pathways it can take from their?
The NH3 can be transferred to pyruvate to form alanine, which is then trasfered int eh blood to the liver to join the urea cycle. Or, glutamate can, with NADPH, release it directly into the blood as amonium.
What is the difference between pyruvate and alanine?
an NH3 group.
What is the function of the urea cycle?
a molecule that hleps dispose of excess nitrogen.
What tissue does it occur in?
Liver
What part of the cell?
The first two reactions in mitochondria, the rest in cytoplasm
How many molecules of nitrogen are in urea?
Two
What molecules do they come from?
one if free amonium, the other from asparatate.
What is the immediate precursor of both moleulces?
Glutamate provides free amonium (see aboe), and is also converted into aspartate.
What are the reactions?
Ornithine into Carbamoyl phosphate into citruline, add asparate becomes arginosuccinate, fumerate leaves, leaving arginine, produces urea and ornithing again.
Neumonic for this?
Ordinarrily Careless Crappers Are Also Frivolous About Urination.
Is this reversible?
No, highly irreversible
Which reactions happen in the mitochondria?
Carbamoyl phsophate is formed there, and added to ornithine to make citruline.
What a.a. does Histamine come from?
Histadine
What a.a. does creatinine come from?
arginine
What a.a. does throxine come from?
Tyrosine (which comes from phenylalanine)
What a.a. does niacin come from?
Tryptophan
What a.a. does heme come from?
The porphyrin comes from glycine
What a.a. does melatonin come from?
Tryptophan
What a.a. does NE and Epi come from?
Dopamine, which comes from tyrosine
What a.a. does Urea come from?
arginine (the NH3 is donated by glutamate)
What a.a. does melanin come from?
Dopamine, which comes from tyrosine
What a.a. does dopamine come from?
Tyrosine (which comes from phenylalanine)
What a.a. does seratonin come from?
Tryptophan
What a.a. does Nitric oxide come from?
Arginine
What a.a. does NADP come from?
Niacin, which comes from tryptophan
What is the primary problems in PKU?
Phenylalanine cannt be converted into tyrosine
What does this cause?
Tyrosein becomes essentail and phenylalanine builds up in blood and spills into urine.
What are the clinical findings?
fair skin and eyes (no melanin), mental retardation (seratonin lack?) and a musty odor.
Treatement?
Restirction phenylalanine, ingest tyrosine
What is the primary problems in Alkaptonuria?
lack of an enzyme in the tyroine degradation pahtywa
What enzyme?
homogentisic oxidase
What are the clinical findings?
Dark urine and connective tissue
Is the benign?
Yes. Can have arthralgias.
What is the primary problems in this Homocystinuria?
two possible: Can't make homocysinte into cystine, or can't make homocystine into methionine.
Results of this defect?
If it is homocystine to cystine that is impaired, cystine is essential. IT can cause mental retardation, osteoperosis, and lens dislocation.
Treatment?
If it is homocystine to cystine, you give cystine. If it is homocystine to methionine you give methionine.
What co-factor is used to change homocystine to methionine?
Vitamine B12 and tetrahydrofolate
Can increased Vit B 12 be theraputic?
Yes, if the problem is the affinityof the enzyme for its co-factors
What is the primary problems in Albinism?
Inability to make melanin from tyrosine
Causes?
lack of tyrosinase (inability to syntehsize melanin from tyrosine), defective tyrosine transporters, or a lack of migration of neural crest cells
Risks it causes?
Lack of melanin leads to risk of skin cancer
What is the primary problem in this Cystinuria?
Lack of a.a. transporter in kidney
What a.a. are effected?
COLA: Cystine, Ornithine, Lysine, and Arginine
What are the clinical effects?
Kidney stones made of cystine (radiolucent)
Treatment?
Acetazolamide
How does it work?
alkalinizes the urine
What is the primary problem in Maple Syrup Urine Disease?
block in degredation of branches aa
Which are those?
I Love Vermont Maple Syrup: Ile, Leu, Val
What are the clinical signs?
Urine smells like maple syrup, leads to mental retardatrion, CNS defects, and death.
Adensoine deaminase deficiency leads to what condition?
SCID
SCID affects T cells, B cells, or both?
Both
Lesch-Nyhan syndrone (LNS) results in inability to salvage which nucleotide?
Purine
LNS has which inheritance pattern?
X-linked recessive
Result of LNS is excess production of __________.
Uric acid (gout is one finding in LNS)
Fatty acids are synthesized in the _________.
Cytosol
Fatty acids are degraded in __________.
Mitochondria (where products will be consumed)
Fatty acid entry into cystol is via ________.
Citrate shuttle
Fatty acid entry into mitochondria is via _______, which is inhibited by _________.
carnitine shuttle; cytoplasmic malonyl CoA
In fasting state, fatty acids are ultimately converted to what?
Ketone bodies
What is the end result of all glycogen storage diseases?
Abnormal glycogen metabolism and accumulation of glycogen in cells
Type I is also known as _______.
Von Gierke's disease
What is the deficiency in type I/Von Gierke's disease?
Glucose 6-phosphatase deficiency
Findings in type I/Von Gierke's disease are ________ and _________.
Severe fasting hypoglycemia, excess glycogen in liver
Type II is also known as ______.
Pompe's disease
What is the deficiency in type II/Pompe's disease?
Lysosomal alpha-1,4 glucosidase deficiency
Findings in type II/Pompe's disease are _________ and _________.
Cardiomegaly, systemic findings (liver, muscle)
Type III is also known as _____.
Cori's
What is the deficiency in type III/Cori's?
Debranching enzyme alpha-1,6-glucosidase deficiency
Type IV is also known as _______.
McArdle's disease
What is the deficiency in type IV/McArdle's disease?
Skeletal muscle glycogen phosphorylase deficiency (McArdle's = Muscle)
Result of type IV/McArdle's disease is _________.
Increased glycogen in muscle, but can't be broken down (results in cramps, myoglobinuria)
What is the pneumonic to remember types I through IV?
Very Poor Carbohydrate Metabolism (von gierke's pompe's cori's mccardeles)
What are two incidences when ketone bodies found in urine?
Prolonged starvation, diabetic ketoacidosis
Ketone bodies are made from _______.
HMG-CoA
Ketone bodies are metabolized by the brain to 2 molecules of ________.
Acetyl-CoA
Where is insulin made?
Beta cells of pancreas
Insulin does not affect glucose uptake in _____, ______, or _______.
Brain, RBCs, hepatocytes
Required for uptake of glucose by ______ and _______.
Adipose tissue, skeletal muscle
GLUT_ receptors are found in beta cells and GLUT_ receptors in muscle and fat.
2,4
Inhibits glucagon release by what cells?
Alpha cells of pancreas
True/False: Serum C-peptide is present with exogenous insulin uptake.
FALSE
Glucagon _______ stuff, turns glycogen synthase _____, turns phosphorylase ___.
Phosphorylates, OFF, ON
Phosphorylates, OFF, ON
Insulin _______ stuff, turns glycogen synthase _____, turns phosphorylase ___.
Dephosphorylates, ON, OFF
Rate limiting step is catalyzed by what enzyme?
HMG-CoA reductase
Lovastatin (inhibits/stimulates) HMG-CoA reductase.
Inhibits
2/3 of plasma cholesterol is esterified by _____________.
Lecithin-cholesterol acyltransferase (LCAT)
A-I does what?
Activates LCAT
B-100 binds to _______ receptor.
LDL
C-II is a cofactor for what enzyme?
Lipoprotein lipase
E does what?
Mediates extra (remnant) uptake
Chylomicrons deliver dietary _____ to ________ and dietary ______ to ______.
Triglycerides, peripheral tissues; Cholesterol, liver
Which cells secrete chylomicrons?
Intestinal epithelial cells
Secretion is mediated by apolipoprotein _______.
B-48
True/False: VLDL delivers hepatic triglycerides to peripheral tissues.
TRUE
Where is VLDL secreted from?
Liver
LDL delivers hepatic cholesterol to _______.
Peripheral tissues
LDL is taken up by target cells via what process?
Receptor-mediated endocytosis
HDL mediates transport of cholesterol from where to where?
Periphery to liver (reverse cholesterol transport)
HDL acts as a repository for ______ and _______.
apoC and apoE
HDL is secreted from which 2 places?
Liver and intestine
Type I (hyperchylomicronemia) has elevated blood levels of ______.
Triglycerides
Type IIa (hypercholesterolemia) has increased levels of what?
LDL
What is the pathophysiology of type IIa?
Decreased number of LDL receptors
Type IIb (combined hyperlipidemia) has increased levels of ____ and _____.
LDL, VLDL
Type III (dysbetalipoproteinemia) has altered apolipoprotein __, and increased ____ and _____.
E, IDL, VLDL
Type IV (hypertriglyceridemia) is caused by hepatic overproduction of what?
VLDL
True/False: Type V (mixed hypertriglyericdemia) has only increased VLDL
False; Increased VLDL and chylomicrons
ALA synthesis is the rate-limiting step for the produciton of what?
Heme
ALA is found in the ______
Mitochondria
Heme synthesis occurs in the ______ and ________.
Liver, bone marrow
Underproduction of heme causes ___________ ___________ _________.
Microcytic hypochromatic anemia
Accumulation of intermediates causes what?
Porphyria
This type of porphyria is marked by a deficiency in uroporphyrinogen I synthetase
Acute intermittent porphyria
How does lead affect iron incorporation into heme?
It prevents it
This is the most common type of porphyria; a deficiency in uroporphynogen decarboxylase)
Porphyria cutanea tarda
True/False: The progression of heme catabolism is heme --> biliverdin --> bilirubin
TRUE
Bilirubin is (Toxic/Non-toxic) to CNS and transported by _________.
Toxic, albumin
In the liver, heme is conjugated with __________.
Glucuronate
True/False: Urobilinogen is an intestinal intermediate that is never found in the blood and urine.
False: a small amount is reabsorbed into blood and excreted in urine.
Hemoglobin is composed of how many polypeptide subunits?+A105
4 (2 alpha, 2 beta)
Carbon monoxide has a 200x (higher/lower) affinity for hemoglobin than does oxygen
Higher
T (taut) form of hemoglobin has a (high/low) affinity for oxygen
Low
R (relaxed) form of hemoglobin has a (high/low) affinity for oxygen
High
True/False: Myoglobin, like hemoglobin, has a sigmoid-shaped O2 binding curve.
FALSE
Increased Cl, H, CO2, DPG, and temperature favor shift over curve to (left/right).
Right (unloads more O2)
True/False: Shift to right is due to preference for T form over R form.
TRUE
True/False: Methemoglobin is an oxidized form of hemoglobin that binds O2 more readily.
False: it binds O2 less readily
CO2 binds to (heme/amino acids in globin chain).
Amino acids in globin chain
CO2 binding favors which form of hemoglobin? And what sort of shift does it cause?
T. Right shift.
Increased Cl, H, CO2, DPG, and temperature favor shift over curve to (left/right).
Right (unloads more O2)
True/False: Shift to right is due to preference for T form over R form.
TRUE
True/False: Methemoglobin is an oxidized form of hemoglobin that binds O2 more readily.
False: it binds O2 less readily
CO2 binds to (heme/amino acids in globin chain).
Amino acids in globin chain
CO2 binding favors which form of hemoglobin? And what sort of shift does it cause?
T. Right shift.