STEP 1: Biochem
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- NADPH Production
-
HMP Shunt
(Non-oxidative pathway) -
Ribulose-5-Phosphate
Think ___, and _____. -
1. Need for NADPH
2. Cholesterol biosynthesis in liver -
Fasting after 4 hours:
blood glucose is maintained by
_________
think________ --> _______ -
Gluconeogenesis
Oxaloacetate to phenylpyruvate -
Ketogenesis:
Think these 3 things:
-
1. Phosphorylation/dephosphorylation of acyl CoA
2. Activated by glucagon
3. Deactivated by Insulin - In protein catabolism, amino acids lose their ____ to compounds like ____ in a _____ reaction.
-
Nitrogen, glutamate, transamination
This nitrogen is then used to form ammonia and is excreted in urine after conversion to urea -
Photosensitive Porphyrias occur in later exzyme defieciencies
These will include:
(4) -
1. URO decarboxylase,
2. Copro Oxidase,
3. Ferrochelotase,
4. Proto-oxidase - ascorbic acid =
- Vitamin C
-
Vit B2 =
Lack of causes: -
Riboflavin
Cheilosis, stomatitis, glossitis, dermatitis
Think pt with small cuts in corner of mouth and swollen tongue - Folic Acid Deficiency =
- Megaloblastic anemia and neural tube defects in fetus
-
Need Folate (= vit B____)
For ___, ___ and _____. - Nucleotide biosynthesis, remethylation of homocystein, and DNA repair
-
Zinc deficiency:
Look for ____, ____, and ____ - acrodermatitis, growth retardation, infertility
- Tyrosine is present in the body via ___ or ____ and is the precursor for _______.
-
Ingestion or derived from Penylalanine.
Catecholamines:
DOPA, Dopamine, Norepinephrine, Epinephrine - Unlike ____ and ____, _____ is derived almost soley in the adrenals.
-
Dopamine and norepinephrine,
Epinephrine is derived mainly in the adrenals -
Converts Nore-epi --> Epi
Is up regulated by _____ -
PNMT
Cortisol - Thyroid hormones act via _____ receptors
-
nuclear
This means that they lead to direct synthesis of new products - JAK STAT inducers
-
CHIP:
Cytokines, growth Hormone, IL-2, Prolactin
- Thiamine is also needed for _____ which is pertinent to alcoholics
- Succinyl Co-A formation from alpha-ketoglutarate
- Allosterically activates gluconeogenesis
- Acetyl CoA
- increases activity of pyruvate carboxylase
- Acetyl CoA
-
Sucrose =
Lactise =
Maltose = -
S = Fructose + Glucose
L= Galactose + Glucose
M= Glucose + Glucose - Fructose intolerance = ______ deficiency
-
Aldolase B
Remember that Fructose is also in Sucrose - so a fructose in tolerance = a sucrose intolerance as well - Classic galactosemia = ________ impairment
- glactose-1 Phosphate metabolism
-
Baby has FTT after breastfeeding begins.
What enzyme is most likely defiecient? - Galactose-1 Phosphate Uridyl Transferase
-
Fructose in Urine =
Is an Asymptomatic disorder due to the formation of ______ from fructose by _____ -
Fructose 6 P via Hexokinase
(Note Aldolase B deficiency leads to buid-up of Fructose 1 P) -
CO2 carrier
Also called Vitamin _____. - Biotin, B7
- Biotin is needed for these 2 conversions:
-
1. Pyruvate to Oxaloacetate
2. Amino Acids (Valine) to Succinyl Co A -
1. Converts pyruvate in the presence of oxygen
2. pyruvate --> _______ -
1. Pyruvate dehydrogenase
2. Acetyl Co-A -
Amino acids that are purely ketogenic
(2) ie they have no glucogenic components
This means that they will not lead to the formation of ____. -
Leucine and Lysine
Lactic acid - Amino acids that are both ketogenic and glucogenic
-
PIT: "both go in the PIT"
Phanylalanine, Isoleucine, Tryptophan - Infant with FTT and hepatomegaly following a diet change most likely has ____ which is caused by a defieciency in ________.
-
Essential Fructose intolerance
Aldolase B - Steroid receptors are on the cell _____, are ___(protein form)____ , and are bound to ______ such as ____ and ____.
- Nucleus, Zinc Fingers, Heat shock proteins, hsp90 and hsp56
- cAMP receptors are bound to a ______ that activates _____ which then activates more cAMP and thus ____.
- G Protein, adenylyl cyclase, Protein Kinase A
-
The ultimate Goal of the IP3 pathway is to increase ________.
THe pathway is:
___ --> ____ --> ____ --> ____-->____ -
Cytosolic Ca++
Receptor --> phospholipase C
-->IP3+DAG -->increased Ca++ --> Prot. Kinase C - Ras is part of the ______ system
- MAP Kinase
- After the steroid receptor complex forms, the _____ are lost and the complex _______.
- Heat shock proteins (hsp 56 and 90), the complex then enters the nucleus to initiate transcription
- NAD+ is rejuvenated for the anaerobic process when ___ is converted to ____
- Pyruvate --> Lactate
- Increased concentrations of _____ inhibit the process of glycolysis
- Citrate
- These cells are able to convert Sorbitol to _____ with the enzyme ____
-
Seminal Vessicle Cells
Fructose, sorbitol dehydrogenase
Cells that lack Sorb Deh, such as liver, kidney, retinal, lens, schwann.... are thus at greater risk in cases of high glucose - ie diabetes. - Pellagra is caused by _____ deficiency
- Niacin
- When not derived from food, Niacin can be made endogenously from ____.
- Tryptophan
- Arginine is neccessary for the creation of ____, ___ and ____.
- Nitric oxide, creatine, urea
- The precursor for vitamin A is ____.
- Carotene
- Pellagra is characterized by ___, ___ and ___, and can be found in populations that subsist solely on ____.
-
Dermatitis, diarrhea, and dementia.
Corn - Pyrimidine is formed from ____.
- Orotic acid
- GTP is produced in the TCA cycle in this step, and it is used to phosphorylate phosphoenolpyruvate in gluconeogenesis.
- Succinyl Co-a --> Succinate
- Valine, alanine, isoleucine + Alpha-helical arrangement =
- Membrane spanning portion of membrane protein
- Membrane spanning proteins are usually messengers for these types of hormones:
- Glycoprotein hormones such as TSH, FSH, and LH
- Creatine increases ___ in most cells of the body, is mostly stored in ______ and is first limited by the enzyme ______ in the kidneys and pancrease, and then _______ in the liver and pancrease
- ATP, skeletal muscle, GATM, GAMT
- Hydrophobic Amino Acids (as in the kind that could be in the membrane spanning portion of a cell membrane)
-
PAM VI hates water
Phenylalanine, Alanine, Methionine, Valine, Isoleucine - Beta cells release insulin when the ______ ratio increases, shutting down the _____ which opens _______ .
-
ATP:ADP ratio
Potassium channel (KATP) shuts down
Opens Ca++ volatage gated channels which release insulin -
Glucose sensor in Beta cells.
Can be deficient in Gestational Diabetes. - Glucokinase
- Glucise 6 Phosphatase is only present in the ____
- liver
- Infant with growth retardation, hepatomegaly, and hypoglycemia lacks _____
- debranching enzyme
- Hemolytic anemia can occur with ____ deficiency
- pyruvate kinase
- Muscle cramping and exercise intolerance can be caused by a lack in ______
- Glycogen phosphorylase
- ______ deficiency causes a shunt toward _______ production from galactose via _______ causing bilateral cataracts.
-
Galactose Kinse deficiency causes increased Galactitol production via Aldose reductase.
Increased Galctitol causes cataracts -
Vitamin _____ is useful in treating Measles.
Think child from ______. - A, deficiency is common in Asia, Africa, and S America
- Tryptophan is the precursor for ____, ____ and _____.
- Nicotinic Acid, serotonin, melatonin.
-
Tryptophan deficiency is called ________.
Children with the intestinal absorptive issues of this disease have _______ symptoms because tryptophan is a precursor for ______. -
Hartnup disease
Pellagra-like
Niacin - _____ bonds in ______ cause recoil abilities in ______.
- Lysine, elastin, Alveolar
- HbC Disease is caused by a ______ mutation that switches the normal _____ to a _____.
- missense, glutamine (normal) is switched to Lysine
- IN HbS, ______ is switched to ____.
- Glutamic acid is swtched to valine
- Movement of unconjugated bilirubin into the liver is ______ and movement of conjugated bilirubin to be excreted is ____.
- passive, direct bilirubin excretion is active.
- Unconjugated bilirubin is _____ and must be bound to ____.
- not water soluble, must be bound to albumin
- Fetal blood has 50% _______ and takes _____ to switch to HbA.
- HbF, 6 months
- ______, formed from ______, is a methyl donor.
- SAM, methionine
-
The START codon for all ribosomal translations is ____, which codes for ____.
Thus, it is present at all the ______. - AUG, methionine, N-terminal position for all proteins
- Homocystien is converted to ____.
- Methionine
-
Homocysteinuria occurs in ____ deficiency.
Pts cannot make ____. -
Vitamin b12 / cobalamin
Methionine - Periodic Hemolytic anemia can be cause by _____ or ______ deficiency.
- G6PD, Glutathione reductase
- Chronic Hemolytic anemia will most often (95%) be caused by a ____ deficiency.
- pyruvate Kinase
- Pyruvate dehydrogenase requires ___, ____, ___, ___and ____ as cofactors.
- Thiamine, lipoic acid, Coa, FAD, NAD+
- Without lipoic acid there will be ____ because ____ cannot be converted to ____.
-
lactic acidosis, pyruvate cannot be converted to acetyl Co-A
The pyruvate is shunted towards lactate formation -
The Hemoglobin Curve shifts RIGHT when these three things ______.
-
INCREASE in
Temperature,
2,3 DPG
H+/ acid - THe hemoglobin curve shifts LEFT when these three things _____.
-
DECREASE
Temperature
2,3 DPG
H+ (more basic) - A decreased P50 causes ______ because ____ oxygen is released to tissues.
- REFLEX polycythemia because LESS oxygen is released to tissues
- 2,3 BPG is in _____ and increases when blood oxygen levels are ____ in order to ____ oxygen movement INTO tissues.
-
RBCs, LOW, INCREASE
When blood oxygen is low, 2,3 BPG ensures that the oxygen available will be moved INTO the tissues. - Spoon nails (koilinychia) and difficulty swallowing (dysphagia) = ____
- Iron deficiency anemia
- heme synthesis in the liver is used for _____ as opposed to heme produced in the bone marroe, which is used for ___
-
liver: cytochrome P450 system
marrow: hemoglobin synthesis -
decreased heme will ____ hepatic ALA synthase activity.
This can cause ___, ___, and ___. -
increaes
abdominal pain, neurological issues, dark urine with standing - Acute intermittent porphyria is an _______ disease cause by _____ deficiency.
-
autosomal dominant, porphobilinogen deaminase.
The low heme levels increase ALA synthase activity. Thus, is can be treated with heme components. - Acute porphyria attacks can be brought on my ____ (3)_____.
-
Alcohol, barbituates, hypoxia
(also a low calorie diet) - RBCs use the HMP shunt to _______.
- Maintain high levels of NADPH to keep glutathione reduced
-
G6PD is a common _________ disease (think African Americans) that can cause acute anemia.
A common symptom is ____.
____ is not formed. -
X-linked
Dark urine
6 phosphogluconate - G6PD deficiency leads to RBC destruction because of ____.
-
oxidative stress
- UTI = ____ as treatment which can cause ______ leading to an anemic episode in patients with ____.
-
trimethoprim-sulfamethoxazol
oxidative hemolysis
G6PD deficiency -
The formation of ______ stabilizes the hemoglobin molecule and allows for release of oxygen at the tissue level.
These form when ____ is high, which means that _____ are available. (pH is ___) -
salt bridges, CO2 is high, protons (lowered pH)
Histidine amino groups on the hemoglobin molecule can be protonated, forming salt bridges that stabilize the de-oxy hemoglobin molecule - In the lungs, hemoglobin binds ___ and loses ___.
-
Lungs:
Binds oxygen, loses protons - O2 partial pressure in blood is ____.
-
the amount of oxygen dissolved in the plasma.
It is NOT related to hemoglobin O2 saturation -
Ferrous to _____ iron on the heme molecule leads to the formation of ____.
This _____bind oxygen. -
Ferric (3+)
Forms Methemeglobin which CAN NOT bind oxygen - UV damage causes ____ formation which is corrected by ___.
- pyrimidine dimer, endonuclease repair in which the damaged region is nicked and replaced.
- CO poisoning is dangerous because it has a _________.
- 200xs greater affinity for hemoglobin than oxygen, and once bound, is irreversible.
-
a-ketoglutarate to Succinyl Co-A requires ___.
-
Thiamine
In an alcoholic vignette for biochem, think a-ketog to Succ Co-a -
Pantothenic acid = _____
Think ___ --> ____ in the TCA cycle -
Co-enzyme A
Oxaloacetate to Citrate -
HbF does not bind ____.
HbF will continue to be produced if there is a mutation where ___ is replaced with ___. -
2,3 DPG (in order to get blood from the placenta)
histidine, serine -
1. Rate limiting enzyme of the HMP shunt
2. Deficiency causes _____ -
1. G6PD
2. Hemolytic Anemia
Can be exacerbated by sulfonamides, anti-malarials, FAVA BEANS
-
____ and _____ carry out the non-oxidative functions of the HMP shunt.
They allow for conversion of ___ to ____.
-
Transaldolase and Transkelotase
Fructose-6-phosphate to Ribose. - the HbS mutation allows for _________ in _____ or ____ conditions
- hydrophobic interaction between Hgb molecules in low oxygen or acidic conditions
- Glutamate carboxylation is carried out by Vitamin ___.
- K
- Transkelotase requires _____, is part of the _______ which is carried out in the _____.
- Thiamine, Pentose Phosphate Pathway, CYTOSOL
-
If the individual sub units of hemoglobin were dissociated, individually they would have a much _____ oxygen affinity and ____ P50.
Their curve would be sinilar to that of ____. -
HIgher O2 affinity = LOWER P50
Shifts FAR left like MYOGLOBIN - 3 STOP codons
-
UGA
UAG
UAA
- Infant with Cardiomegaly + polysaccharide deposits in muscle = ____ deficiency
- a-glucosidase
-
RBCs use ____ to deal with the high CO2 concentration of venous blood.
The action of this enzyme causes higher levels of __ in the RBCs -
Carbonic anhydrase
RBC Chloride levels are high in venous blood -
HbF is made up of ____ and ___.
Therefore, in ___ thalassemia, the infant will be normal for the first 6 months. -
alpha and gamma HgB
Beta - Maturing erythrocytes cannot produce heme when they lose their ___.
-
mitochondria
The 1st and last 3 steps of heme synthesis occur in the mitochondria - The greenish color in bruises is caused by the formation of ____ via ____.
- Bilverden, heme oxygenase
- Nitrites (ie amyl nitrite) work to resolve deathly affects of cyanide by causing the formation of _____ which binds cyanide more readily, thus keeping away from _____.
-
Methemeglobin (ferric hemoglobin)
Mitochondrial cytochrome complex - Radiation treatment causes _____ and the formation of ____.
-
Double strand DNA breakage
Free radicals - Collagen structure is ____.
- Triple Helix: Gly-X-Y
- Nitrogen in urea is derived from ____ and ___.
-
NH3 and Aspartate
"A Spartan in the NHL needs to pee."
Carbamoyl Synthetase Phosphate 1 is the rate limiting enzyme in urea synthesis. - ______ is elevated in Lead poisoning and is neccessary for the production of _____.
-
Pyridoxal Phosphate
d-Aminolevulinic Acid -
___________ participates in amino acid transfer.
Think oxaloacetate + Glutamate --> Aspartate -
Pyridoxal Phosphate
(Pyridoxine) - Cytosine Deamination = ______
- Uracil Formation
-
____ activates carbamoyl phosphate synthetase 1.
It is Formed from ______ and ____. -
N-Acetyl Glutamate
Acetyl CoA, Glutamate -
____ becomes arthritis in adults. (Think darkening of ears).
It is caused by a lack of ____. -
Alkoptonuria
Homogentisic acid oxidase
The accumulated homogentisic acid cases brown spots throughout the body. -
Bacterial Polymerase Function:
1: _____
3: _____ -
1. Removes RNA primer, repars knick of removing primer
3. Removes mismatched nucleotides - Joins Laggin (Okazaki) fragments
- DNA Ligase
- The Lac operon is turned OFF when ______ or when _____.
- Glucose is present, cAMP is low
- Enteropeptidase is neccessary for the formation of ______.
-
Trypsin
It is formed from trypsinogen in the duodenal wall. -
____ is converted to urea via ___.
-
Arginine, Arginase
Deficiency causes a spasticity and choreoid movement similar to that seen in Cerebral Palsey - Increased Serum methionine could mean ____ deficiency which leads to absence of ____.
-
Cystethionine Synthetase
Cysteine - _____ (BH4) is a cofactor for the production of ______(4).
-
Tetrahydrobiopterin
Serotonin
Nitric Oxide
Tyrosine
Dopa -
These 3 enzymes require 5 cofactors.
NAD, FAD, Thiamine, Lipoate, Coenzyme A -
a-ketoacid dehydrogenase (Maple Syrup)
Pyruvate dehydrogenase
a-ketoglutarate dehydrogenase -
Ehlors Danlos occurs with a defect in ____.
Think of these 2 symptoms. -
Collagen
Hypermobile Joints, Elastic skin - Bacterial mRNA can be ____.
-
Polycistronic
1mRNA codes for several proteins - Thiamine deficiency can be determined by measuring erythrocyte ____ levels.
- Transkelotase
- Lactose may also be written as ____
- Galactosyl b 1,4-Glucose
- "mousy" odor and European descent = ____
-
PKU
They need TYROSINE - Blck Urine = ______ = ____ deficiency
- Alkaptonuria, homogentisate oxidase
- Histone _____ is located OUTSIDE of the nucleosome.
- H1
- Vitamin C is required to avoid ____ and is used in collagen synthesis within the ___.
-
Scurvy
RER - Amino group + a-ketoglutarate = _____
-
Glutamate
Glutamate carries the amino group that results in amino acid catabolism -
Methlmalonyl CoA is an isomer of ____ which can enter the TCA cycle.
Methymalonic aciduria is caused by ___ deficiency. -
Succinyl CoA
Isomerase - Ornithine transport is part of _____.
- Urea formation / ammonia conversion following amino acid degradation
- Very long chain fatty acid oxidation occurs in ____. If these structures are absent, there will often be ____ issues due to problem with _____.
-
Peroxisomes
Neurological issues develop due to an inability to properly myelinate neurons