Biochemistry Flashcards
What is the most common intracellular buffer?
Protein
What is the most common extracellular buffer?
Bicarbonate
What is a zwitterion?
A molecule with one negative and one positive end
What is the isoelectric point?
The pH at which there is no net charge
What is the rate limiting enzyme in glycolysis?
PFK-1
What is the rate limiting enzyme in gluconeogenesis?
Pyruvate carboxylase
What is the rate limiting enzyme in the HMP shunt?
G-6PD
What is the rate limiting enzyme in glycogenesis?
Glycogen synthase
What is the rate limiting enzyme in glycogenolysis?
Glycogen phosphorylase
What is the rate limiting enzyme in fatty acid synthesis?
AcCoA carboxylase
What is the rate limiting enzyme in beta oxidation?
CAT-1
What is the rate limiting enzyme in cholesterol synthesis?
HMG CoA reductase
What is the rate limiting enzyme in ketogenosis?
HMG CoA synthase
What is the rate limiting enzyme in purine synthesis?
PRPP synthase
What is the rate limiting enzyme in pyrimidine synthesis?
Aspartate transcarbamoylase
What is the rate limiting enzyme in the TCA cycle?
Isocitrate dehydrogenase
What is the rate limiting enzyme in the urea cycle?
CPS-1
What is the rate limiting enzyme in heme synthesis?
Delta-ALA synthase
What are the catabolic pathways that create energy?
ABC
Acetyl CoA production
Beta-oxidation
Citric acid cycle
What are the anabolic pathways that store energy?
EFGH ER Fatty acid synthesis Glycolysis HMP shunt
What are the anabolic and catabolic pathways?
HUG
Heme synthesis
Urea cycle
Gluconeogenesis
Isomerase
Creates an isomer
Glucose fructose
Epimerase
Creates an epimer
Glucose galactose
Mutase
Moves side chain from one carbon to another carbon
Transferase
Moves side chain from one substrate to another
Transaminase
Moves amino group
Kinase
Phosphorylates using ATP
Phosphorylase
Phosphorylates using Pi
Carboxylase
Forms C-C bonds using CO2, ATP, and biotin
Synthase
Stacks substrates, does not use ATP
Synthetase
Stacks substrates, uses ATP
Phosphatase
Breaks phosphate bond
Hydrolase
Breaks a bond with water
Lyase
Cuts C-C bond with ATP
Dehydrogenase
Removes H with a cofactor (NADH, FADH2)
Thio-
Breaks sulfur bonds
Diffusion
From high to low concentration
Active transport
Goes against concentration gradient
Zero-order kinetics
Metabolism independent of concentration
First-order kinetics
Constant drug percentage metabolism over time, depends on concentration
Efficacy
Max effect regardless of dose
Lower with non-competitive antagonist
What affects efficacy?
Vmax
Potency
Amount of drug needed to produce effect
Lower with competitive antagonist
What affects potency?
Km
Km
Concentration of drug that binds 50% of receptors
EC50
Concentration of drug that produces 50% of maximal response
Competitive inhibition
Fights for active site
No change in Vmax
Decreases potency
Non-competitive inhibition
Binds regulatory site
No change in Km
Decreases Vmax
Decreases efficacy
Endothermic reaction
Consumes heat
Feels cold
Exothermic reaction
Gives off heat
Feels warm
Peak level
4 hours after dose
Too high —> decreases dose
Trough level
2 hours before dose
Too high —> give less often
(Unless q6 hour drug, then 1 hour before dose)
t1/2
Half-life
Time it takes for the body to use half of the drug ingested
von Gierke
G-6Pase deficiency
Hypoglycemia
Hepatosplenomegaly
Pompe’s
Cardiac alpha-1,4-glucosidase deficiency
DIE early
Cori’s
Debranching enzyme deficiency
SHORT branches of glycogen
Anderson’s
Branching enzyme deficiency
LONG chains of glycogen
McArdle’s
Muscle phosphorylase deficiency
Muscle cramps with exercise
Essential fructosuria
Fructokinase deficiency
Excrete fructose
Still have hexokinase so benign (incidental finding usually)
Fructosemia
“Fructose intolerance”
Aldolase B deficiency
Liver damage
Galactokinase deficiency causes?
Cataracts
Galactosemia causes?
Cataracts
Mental retardation
Liver damage
What does the citrate shuttle do?
Fatty acid transport out of the mitochondria
What does the carnitine shuttle do?
Fatty acid transport into the mitochondria
What lysosomal diseases have a cherry-red macula? (2)
Tay-Sachs
Neimann-Pick
What lysosomal diseases have a gargoyle face? (2)
Gaucher’s
Hurler’s
Tay-Sachs
Hexosaminidase A deficiency
Blindness
Incoordination
Dementia
Sandhoff’s
Hexosaminidase A/B deficiency
Gaucher’s
Glucocerebrosidase deficiency
Wrinkled tissue macrophage
Bone pain
Neimann-Pick
Sphingomyelinase deficiency
Zebra bodies
Fabry’s
Alpha-galactosidase deficiency
Corneal clouding
Attacks baby’s kidneys
X-linked
Krabbe’s
Beta-galactosidase deficiency
Globoid bodies
Metachromatic leukodystrophy
Arylsulfatase deficiency
Childhood multiple sclerosis
Hunter’s
Iduronidase deficiency
Milder form
Hurler’s
Iduronidase deficiency
Worse form
Lesch-Nyhan
HGPRT deficiency
Gout
Neuropathy
Self-mutilation
Hypoxanthine guanine phosphoribosyltransferase
(Herbert self mutilates)
What do white diaper crystals suggest?
Excess orotic acid
What does biotin act as a cofactor for by donating CO2?
Carboxylation
What does THF donate methyl groups for?
Nucleotides
What does SAM donate methyl groups for?
All other reactions (not nucleotides - THF)
What is the difference between heterochromatin and euchromatin?
Heterochromatin — tightly coiled
Euchromatin — loose (10nm fibers), active
What are the purines?
Pur As Gold
What are the pyrimidines?
C, U, T
Silent mutation
Changes leave the same amino acid
Point mutation
Changes one base
Transition (mutation)
Changes one purine to another purine or pyrimidine to pyrimidine
Transversion (mutation)
Changes one purine to a pyrimidine or vice versa
Frameshift mutation
Insert or delete 1-2 bases
Missense mutation
Mistaken amino acid substitution
Nonsense mutation
Early stop codon
Southern blot detects?
DNA
Northern blot detects?
RNA
Western blot detects?
Protein
What are the essential amino acids?
PVT TIM HALL Phe - phenylalanine Val - valine Trp - tryptophan Thr - threonine Iso - isoleucine Met - methionine His - histidine Arg - arginine Lys - lysine Leu - leucine
Tyrosine becomes essential if phenylalanine is deficient
Essential fatty acids
Linolenic
Linoleic
Acidic amino acids
Asp
Glu
Basic amino acids
Lys
Arg
Sulfur containing amino acids
Cys
Met
O-bond amino acids
Ser
Thr
Tyr
N-bond amino acids
Asn
Gln
Branched chain amino acids
Can’t LIV without them
Leu
Iso
Val
Aromatic amino acids
Phe
Tyr
Trp
Smallest amino acid
Glycine
Ketogenic amino acids
Lys
Leu
Glucogenic + ketogenic amino acids
PITT Phe Iso Thr Trp
Glucogenic amino acids
All the rest
Trypsin cuts?
Tryp to LA
Lys
Arg
Beta ME cuts?
Sulfur containing amino acids
Cys
Met
Chymotrypsin cuts?
Phe
Tyr
Trp
Carboxypeptidase cuts?
Left(!) of any amino acid on the carboxy terminal (right terminal)
Aminopeptidase cuts?
Right of N terminus
CNBr cuts?
Right of Met
Mercaptoethanol cuts?
Right of Cys, Met
Elastase cuts?
Right of Gly, Ala, Ser
What amino acids does acid hydrolysis denature?
Asn
Gln
What amino acid turns yellow on Nurhydrin reaction?
Proline
All others turn purple
What does alpha1-antitrypsin do?
Inhibits trypsin from getting loose
PKU
No phenylalanine to tyrosine via phenylalanine hydroxylase
Nutrasweet sensitivity
Mental retardation
Pale, blonde hair, blue eyes
Musty odor
Phenylalanine restrictive diet
Tyrosine becomes essential
Albinism
Tyrosinase deficiency
No Tyr to melanin
Maple syrup urine disease
Defective metabolism of branched amino acids (Leu, Iso, Val)
Amino acids leak out into urine
Tastes sweet, smells like burnt sugar
Homocysteinuria
No homocysteine to cysteine COLA stones Cysteine Ornithine Lysine Arginine
Pellagra
Niacin deficiency
4D’s Dermatitis Diarrhea Dementia Death
Hartnup’s
No Trp to make niacin or serotonin
Presents like pellagra
Can mimic corn rich diet
What causes anterior leg bowing?
Neonatal syphilis
What causes lateral leg bowing?
Rickets
What are the names of the B vitamins?
“The Rich Never Lie about Panning Pyrite Filled Creeks”
Vitamin B1: Thiamine Vitamin B2: Riboflavin Vitamin B3: Niacin Vitamin B4: Lipoic acid Vitamin B5: Pantothenic acid Vitamin B6: Pyridoxine Vitamin B9: Folate Vitamin B12: Cobalamin
Vitamin A
Night vision
CSF production
PTH
Vitamin B1 Thiamine
Cofactor for dehydrogenases and transketolase
Vitamin B2 Riboflavin
FAD cofactor
Vitamin B3 Niacin
NAD cofactor
Vitamin B4 Lipoic Acid
Glycolysis
No known disease
Vitamin B5 Pantothenic Acid
Part of AcetylCoA
No known disease
Vitamin B6 Pyridoxine
Cofactor for transaminases
Myelin integrity
Vitamin B9 Folate
Nuclear division
Vitamin B12 Cobalamin
Cofactor for HMT and MMM
Vitamin C
Collagen synthesis
Vitamin D
Mineralization of bones and teeth
Vitamin K
Clotting factors
10, 9, 7, 2, C
Biotin
Cofactor for carboxylation
Calcium
Neuronal function
Atrial depolarization
Smooth muscle contractility
Copper
Collagen synthesis
Iron Fe2+
Hemoglobin function
Electron transport
Bronze pigmentation
Iron deposit in skin
Bronze cirrhosis
Iron deposit in liver
Bronze diabetes
Iron deposit in pancreas
Hemosiderosis
Iron overload in bone marrow
Hemochromatosis
Iron deposit in organs
Magnesium
PTH
Cofactor for kinases
Zinc
Taste buds
Hair
Sperm function
Chromium
Insulin function
Molebdenum
Purine breakdown (xanthine oxidase)
Manganese
Glycolysis
Selenium
Heart function
Deficiency —> dilated cardiomyopathy
Smells like garlic
Tin
Hair growth
Fluoride
Teeth and bone growth
Excess blocks enolase in glycolysis (low energy state)
Iodine
Endocrine function
Kwashiorkor
Malabsorption Big belly (ascites) Protein deficiency
Marasmus
Starvation
Skinny
Calorie deficient
Where does the Pre label send stuff?
Rough Endoplasmic Reticulum
Where does the Pro label send stuff?
Golgi
Where does the Mannose-6-Phosphate send stuff?
Lysosome
Where does the N-terminal sequence send stuff?
Mitochondria
What are the 4 types of collagen?
SCAB
1: Skin, bone
2: Connective tissue, aqueous humor
3: Arteries
4: Basement membrane
How does scleroderma present?
Tight skin
How does Ehlers Danlos present?
Hyperstretchable skin
How does Marfan’s present?
Hyperextensible joints Arachnodactyly Wing span longer than height Aortic root dilation Aortic aneurysm Mitral valve prolapse Dislocated lens from bottom —> look up to Mars
How does Homocysteinuria present?
Marfan’s in child
Dislocated lens from top —> looking down at child
How does Minky’s kinky hair syndrome present?
Hair looks like copper wire
Copper deficiency
How does Scurvy present?
Bleeding gums and hair follicles
How does Takasayu’s arteritis present?
Asian women with very weak pulse
Granulomatous aortitis
How does Osteogenesis Imperfecta present?
Blue sclera
Shattered bones
Not child abuse