This site is 100% ad supported. Please add an exception to adblock for this site.

Biochem 3 2


undefined, object
copy deck
How many kcal/g?
What % of cal intake?
4 kcal/g
metabbed to glucose- fueel, assist in bowel elim.
How many kcal/g?
What % of cal intake?
9 kcal/g
Precursor for prostas and leukotrienes, carrier molecules for fat-soluble vitamins
How many kcal/g?
What % of cal intake?
Source of the 9 essential AAs for synthing proteins and other N-containing substances.
What is the function of Vitamin A?
Synthesis of rhodopsin (vision), cell differentiation and growth, antioxidant.

Fat soluble
What is the function of Vitamin B1 (thiamine)?
Precursor for TPP, nerve conduction.
Thiamine, TT

Deficiency- dermatitis, enteritis, alopecia, adrenal insufficiency
Which vitamin is a precursor for FAD and FMN?
Vitamin B2 (riboflavin)
Flavin, FFF
2's a Fad
What is the function of Vitamin B3 (Niacin)?
Precursor for NAD and NADP
Niacin, NNN
you have 3 nads?
Which vitamin is a constiuent of Coenzyme A and Fatty Acid Synthase?
Vitamin B5 (pantothenate)
Five Fatties named Amber
Amber=Coenzyme A

Deficiency is rarely seen, but causes dermatitis, hair loss, and GI upset.
What is the function of Vitamin B6 (pyridoxine)?
Precursor for pyridoxal phosphate, heme synth
Which vitamin is a cofactor in methionine metabolism and in propionyl coenzyme A?
Vitamin B12- cobalamin
What is the function of Vitamin C?
Helps collagen synthesis, increases iron absorption in GI tract
Which vitamin is responsible for increaseing CA absorption in kidney and GI?
Vitamin D
What is the function of Vitamin E?
Deficiency- fragile erythrocytes., vision disturbances, neuro dysfunction, and myopathies.
What does Vit. K do?
gamma-caroxylation of II, VII, IX, X.
What is the function of Biotin?
Cofactor for pyruvate carboxylase, propionyl coA carboxylase, and acetyl coenzym A carboxylase.
What is the role of Folate?
cofactor for 1-carbon transfers (methionine and nucleotide synth)
Blood, neuro
Which vitamins are Fat soluble?
A, D, K, E
Which vitamins are metabolic?
B 1,2,3,5 and Biotin
3 y/o boy with dark paatches of flaky skin adn pitting edema of his lower extremities, protuberant abdomen, muscle waisting.
Kwashikor- The inadequate intake of protein with adequate calorie intake. Usually with weaning.
Marasmus- protein-calorie malnutrition from breast milk and cereal diet.

Loss of weight, fat stores, and muscle mass. Protein mass is lost in heart, kidney, liver. Decreased resp function from muscle atrophy. Decreased CO. Decreased albumin-> edema. Immune malfuntion.

Kworshikor- Skin, diarrhea, stunted growth, infection, pitting edema, hepatomegaly
Marasmus- muscle wasting, infection, stunted growth, weakness, anemia
75 y/o with bad night vision. Constipation (oil laxative). 3 bouts of cold, scattered white patches on his conjunctiva as well as two poorly healed cuts on his left hand.
Vitamin A (Retinol) deficiency
Etiology- fat malabsorption, oil laxative, malnutrition.
11-cis-retinol for rhodopsin
Retinoic acid for cell growth and differentiation.
B-carotene for antioxidant.
What happens in Vit A OD?
arthralgia, fatigue, headache, skin changes, sore throat, alopecia, nausea, diarrhea, papilledema, hepatosplenomegaly.
48 y/o with generalized weakness, increased pain on left side adn right thigh. Billroth II gastrectomy. Strength is 4/5. Pain on palpation of 5,6 ribs on left.
Vitamin D deficiency
malabsorption, decreased sun
25- storage
1,25- active
D3- sun
D2- milk

Rickets- kids, skeletal deformities., short, rachitic rosary, craniotabes
Osteomalacia- diffuse bone pain in adults. muscle weakness.
What happens with Vit. D excess?
Hypercalcemia, loss of appetite, stupor, Seen in sarcoid.
72 y/o with ulcerative colitis, diabetes, recent foot ulcer, treated with abtics. multiple bruises, prolonged pt, ptt.
Vit K deficiency
malabsorption and braod spectrum abtics, suppress bowel flora-> decreased K synth.
Prolonged PT, PTT
Normal bleeding time, thrombin time.

Infants have a mild vit. k deficiency from poor diffusion of k across the placenta.
56y/o increased confusion. Inventing stories. Not drunk. Oriented to name, has nystagmus, decreased sensation to pinbrick from knees down. ataxic gate.
Thiamine deficiency
Common in alcoholism.
Precursor for TPP, conenzyme of carba nd AA metabolism. Nerve conduction.

Beriberi and Wernicke-Korsakoff.
Dry Ber1Ber1- polyneuritis, wasiting
wet beriberi- high-output heart failure, edema
Wernicke- encephalopathy- confusion, ataxia, and ophthalmoplegia
Korsakoff- amnesia and confabulation
21y/o with weakness. eats 3-4 days per week. cracked skin at lips. vascularization of corneas.
B2 deficiency
no Fad or Famn
Dermatitis, glossitits, corneal vascularization, angular ceilitis
87 y/o with weakness. Watery, nonbloody diarrhea, difficult remembering. dark scaly patches on neck and back of hands.
B3 (niacin) deficiency
Can come from Hartnup, isoniazid, carcinoid

B3 is derived from tryptophan and B6. INH-decreased b6. Hartnup- decreased trp. Carcinoid- increased trp metab.

Mild- weight loss, weakness, and glossitis
Advanced- pellagra
Pellagra's 3 D's
Diarrhea, Dementia, Dermatitis.
What happens with excess Niacin?
Reduce LDL and VLDL and increases HDL. SEs- Flushing, GI upset
28 y/o with tonic-clinic seizure with no Hx of seizure disorder. On isoniazid. peripheral neuropathy. sideroblastic anemia.
B6 deficiency
caused by INH, OCs
Causes convulsions, hyperirritability, peripheral neuropathy. sideroblastic anemia

precursor for pyridoxal phosphate. Carrier of Amine groups in transamination. Cofactor for cystathionine synth in methionine metab. In synth of heme.

Excess can cause sensory neuropathy
24 y/o w/ onset of diarrhea, weakness, numbness in both legs. Social Hx- sushi. Impaired proprioception and vibratory sensation in both extremities. Smooth red tongue, ataxic gait. Labs- megaloblastic anemia, - schilling.
B12 (Cobalamin) deficiency
Vegans, pernicious anemia, Crohn's, Diphyllobothrium latum, sprue, blind loop.

Cofactor for homo to methionine, methylmalonyl coA to succinyl coA

Neuro- ataxia, impared proprioception, vibratory sensation, glossitis, diarrhea. Megaloblastic anemia.
17 y/o male with generalized weakness, purpura, gingivaal swelling, blaeeding gums, and poorly healed cuts. Anemia.
Vitamin C deficiency
dietary, elderly, alcoholics, homeless or pts with chronic illness

hydroxylation of proline and lysine in synth of collagen. Facilitates Fe absorption.
Scurvy- bleeding into joints, bleeing from gums, anemia, gigival swelling, impaired wound healing.
25 y/o with elevated chol levels. Muscle cramping, scaly skin, hair loss, chronic diarrhea.
Biotin deficiency- abtic uses, raw egg whites (Avitin blocks absorption), long term parenteral nutrition.

cofactor for carboxylation:

rare- dermatitis, Gi, muscle pain, elevated cholesterol.
32 y/o with new seizure disorder. taking phenytoin for 6 months. Tired with watery diarrhea. Pale, smooth red tongue, tachycardic. Megaloblastic
Folate deficiency
Inadequate diet (alcoholics)
Meds, sprue, MTX
Pregs, hemolytic anemia

Synth of dTMP
Homo to meth
75 y/o with SOB, fatigue. Stool is tar-like, microcytic hypochromic anemia. What is causing the fatigue?
Fe deficiency
Blood Loss, diet

Decreased serum Fe, ferritin, increased transferrin saturation.
What happens with too much Fe?
increased free radicals. oxidation of LDL, CV disease.
63 y/o with chronic renal insufficiency. Wrist spasms, increased pain in lumbar spine. Decreased urine output.
Calcium deficiency
malnutrition, renal failure, endocrine

Muscle cramps, tetany, prolonged QT, + Trousseau, Chvostek, Bone pain

Trousseau- spasm with bp cuff removal
Chvostek- twitching of facial muscle with tapping of nerve.
What happens in Iodine deficiency?
needed for T4
hypothyroid, cretinism, myxedema, goiter
What happens in Mg deficiency?
Binds to ATP
Deficiency- increased excitibility, tetany, vent arrhythmias, hypocalcemia
What happens with P deficiency?
Phosphorus- constiuent of bone, cell, nucleic acid
deficiency- rare, but bone pain, skeletal malformations, anemia, platelet malfunction, encephalopathy
What happens in Zinc deficiency?
Zn- cofactor for Metalloenzymes
Dermatitis, increased infection, stunted growth, altered mental status.
How is EtOH metabbed?
Alcohol dehydrogenase and acetaldehyd dehydrogenase break it down.

NAD is the limiting reagent

Zero order kinetics for alcohol dehydrog

Disulfiram ihibits acetaldehyde dehydrogenase (acetaldehyde=hangover)
What happens in EtOH hypoglycemia
Increased NADH/NAD ration in liver.
Pyruvate to lactate
OAA to malate
Inhibbed gluconeo, and hypoglycemia.
Fatty change in liver
What are some DNA excision repair defects?
Xeroderma pigmentosa- UV- thymidine dimers
Ataxia-telangiectasia- X-ray
Blooms- radiation
Fanconi- cross-linking agents
How are DNA, RNA and protein synthed?
5' has the energy
AA's are linked N-C
What are the types of RNA?
mRNA- messenger- largest- transcription
rRNA- ribosomal- most abundant- protein synth
tRNA- transfer- smallest translation
What is restriction fragment lenght polymorphysm analysis (RFLP)?
It is the DNA fingerprint.
Everyone has polymorphisms. These get clipped into fragments. These fragments are different in everyone.
What is PCR?
A process of making multiple copies of a single portion of DNA.

Denatured to generate 2 strands.
Cooling, excess primers annel to a site to be amplified
heat-stable DNA polymerase replicates the sequence.
What is ELISA?
two ways to test:
1) Ag to see if body recognizes it
2) Ab to see if body has Ag.
What are the roles of the following:
RNA polymerase I
RNA polymerase II
RNA polymerase III
TATA and CAAT sequences
Poly A polymerase
AUG sequence
TATA- promoter sequence where mRNA binds.
7-methylguanine- caps the mRNA to protect from degradation.
Poly A- creates a tail to stabalize the mRNA
AUG- start codon- met in eukaryotes, f-met in prokaryotes
UGA, UAA, UAG- stop codons
What is a enhancer? an operator?
Enhancer- binds Transcription Factors
Operator- binds repressors.
Exons and Introns
EXons are EXpressed.
snRNP splice out Introns.
Exons are ligated together
What is unmodified mRNA called?
wobble theory
CCA at 3' binds AA
Center loop is the anti-codon
Wobble theory- 3rd bp is different, but same AA
needed to deliver AAs in the appropriate sequence.
What is the role of aminoacyl-tRNA synthetases
Attaches AA to the tRNA
Uses 1 ATP
mischarged tRNA leads to mismatch
what is a Ribosome? just givve some structural details.
A site: binds tRNA containing the next AA to be added to the peptide
P site: binds tRNA containing growing peptide chain.
What is the role of peptidly transferase?
Peptidly transferase- enzymatic component of the large ribosomal subunit. catalyzes A-site AA.
What is the pattern of mitochondrial inheritance?
Transmitted by mom, all kids will be affected.
Define Variable Expression
Same genotype can have different phenotypes
Define Incomplete Penetrance
Not all those with a genotype will have the phenotype. Penetrance is the likelihood that the phenotype will develop.
Define pleiotropy
1 gene has multiple effects on multiple organs
Define Imprinting
phenotype is different based on whether it is maternal or paternal.
AngleMan- Mom
Prader-Willi- Pop
Define Anticipation
Disease worsens in each generation due to increased repeats. Huntingtons, Fragile X
Define loss of heterozygosity
Pt inherits or develops a mutation in a tumor suppresor gene, the complement must be deleted before cancer develops. (not true of oncogenes)
Define dominant negative
dominant effect. altered gene blocks good gene in a heterozygote
Define Linkage disequilibrium
groups of alleles are inherited together. (by population)
Define Mosaicism
cells have different genetic make-up
Define Locus heterogeneity
Mutations at different loci have the same phenotype.
Define Codominance
Two alleles for the same gene in a heterozygote are both expressed, AB blood.
Define incomplete dominance
Two alleles of the same gene give a mixed phenotype.
What are the conditions of the Hardy Weinberg population?
Large population
Random mating
no emigration or immigration
no mutations
no incest
what are the equations of hardy-weinberg?
allele prevalence- p+q=1
disease prevalence- p2+2pq+q2=1
If sickle cell is an autosomal recessive disease that occurs in 1 out of 400 births, what is the frequency of carriers of the sickle cell trait?
95/1000 is a carrier
Fragile X is an X-linked disease that occurs in 1 out of every 2000 males. what is the frequency of female carriers?
What are the autosomal trisomies?
Downs Syndrome (21) (D- Drinking age is 21)
Edwards' Syndrome (18) (E- Election age 18)
Patau's (13) (P- Puberty 13)
46 y/o mom. baby girl born with flat face, wide-set eyes, epicanthal folds, and 1 palmar crease across each hand. Holocystolic murmur with ventricular septal defect.
Down's syndrome- Trisomy 21
95% meiotic nondisjunction.
4% Robertsonian
1% mosaicism

Description as in case
endocardial cushion defects are common.
Increased risk for ALL and Alzheimers.
Increased age is bad for moms.

Decreased alpha-fetalprotein, Beta-HCG, Increased nuchal translucency.
What is Edwards Syndrome?
Trisomy 18
Mental retard, rocker bottom feet, low-set ears, micrognathia, heart disease, clenched hands, prominent occiput. Death in 1 year.
What is Patau's syndrome?
Trisomy 13
severe mental retardation, microphthalmia, microcephaly, cleft lip/palate, abnl forebrane structures, polydactyly, heart disease, death in 1 year.
What is cri-du-chat syndrome?
deletion of the short arm of 5.
microcephaly, mental retard, high-pitched mewing, epicanthal folds, cardiac abnlties.
What is the Catch-22 of 22q11?
Cleft Palate
Abnormal facies
Thymic aplasia-> bad T-cells
Cardiac defects
Hypocalcemia 2ry to parathyroid aplasia.

velocardiofacial syndrome CAC
DiGeorge TCH
What is the difference between Angelman and Prader-Willi Syndrome?
AngelMan- Mom
Prader-Willi- Pop
Both are a 15q deletion.
PW- retard, hypogonad, obesity
Angelman- Happy Puppet with ataxic gait, innappropriate laughter, retard, seizures
What causes Klinefelters?
Maternal meiotic nondisjunction- 47XXY
2 week old girl with possible congeinal heart defect. weak femoral pulses and broad chest with widely spread nipples. cystic hygroma on the neck (webbed neck)
Turner's Syndrome
Monosomy X
Coartaction of the aorta
broad chest
What causes Fragile X?
CGG repeats in the familial mental retardation gene on the X.

Large testes, large jaw, ears. CT defect with hyperextensible joints and MVP.
What disorders have trinucleotide repeats?
Try hunting for my Fried eggs (X)
myotonic dystrophy
Friedreich's ataxia
Fragile X
What are some common congenital malformations?
1. Heart defects
2. Hypospadias
3. Cleft lip
4. congenital hip dislocation
5. spina bifida
6. anencephaly
7. Pyloric stenosis.
Enzyme kinetics, what is the relationship between Km, Vmax and S?
the lower the Km, higher the affinity.
Km=[s] at 1/2Vmax
competative inhibitors cross.
What are the differences between competative and non-competative inhibitors?
Competative inhibitors resemble substrate
Overcome by an increase in [s]
Bind active site.
Km increases
no change in Vmax

Vmax decreases with noncompetitive inhibitors
How are enzymes regulated?
alteration synth/destruction
covalent modification- Phosphorylation
proteolytic modification- zymogen
allosteric regulation- feedback inhibition
transcriptional regulation- steroid hormones
Rough endoplasmic reticulum:
what does it do?
Synthesis of secretory proteins adn N-linked oligosaccharide addition

Goblet cells and Plasma cells have mad RER
What are Nissl bodies?
Rogh ER, in neurons; not found in axon or axon hillock.
Synthesize enzymes- ChAT adn peptide neurotransmitters
What does the smooth endoplasmic reticulum do?
Steroid synth and detoxification of drugs and poisons.
Liver hepatocytes and steroid hormone- produce cells of the adrenal cortex. Rich in SER.
What are the 6 functions of the golgi apparatus?
1. Distribution center of proteins and lipids from ER to the plasma membrane, lysosomes, and secretory vesicles.
2. Modifies N-oligosaccharides on asparagine
3. Adds O-oligosaccharides to serine and threonine residues
4. Proteoglycan assembly from proteoglycan core proteins
5. sulfation of sugars in proteoglycans and of tyr on proteins.
6. mannose-6-phosphate to specific lysosomal proteins, whcih targets the protein to the lysosome.

I-cell disease- lacks mannose-6-phosphate

DAT Poor Small Man
Alpha and beta tubulin dimers. Each has 2 GTP bound. Incorporated into flagella, cilia, mitotic spindles.
Grows slowly, collapses quickly.
Slow axoplasmic transport in neurons.
What drugs affect microtubules?
Mebendazole/thiabendazole (antihelminth)
Taxol (breast cancer)
Griseofulvin (antifungal)
Vincristine/vinblastine (anticancer)
Colchicine (anti-gout)
What is Chediak-Higashi syndrome
microtubule polymerization defect resulting in decreased phagocytosis.
How is cilia structured?
9+2 microtubule arrangement.
Dynein is an ATPase that links peripheral doublets, bending of cilium.
What is Kartagener's syndrome?
Dynein arm defect- immotile cilia.
What is the composition of the plasma membrane?
Cholesterol 50%- stability
Phospholipids 50%
shingolipids, glycolipids and proteins.
Hich chol or long saturated fatty acid contennt increases the melting temperature.
Noncytoplasmic side contains glycosylated lipids or proteins.
What is the function of Phosphatidly choline?
Lecithin, major component of RBC membranes, of myeline, of bile and of surfactant. DPPC- dipalmitoyl phosphatidylcholine) Also in the esterfication of cholesterol (LCAT is lecithin-cholesterol acyltransferase)
What's the big deal with Na-K ATPase pump?
plasma membrane. 3 Na out, 2 K in. pump is phosphorylated during cycle.

Ouabain inhibits by binding to K site. Digoxin, also inhibit causeing increased contractility.
What receptors use the phospholipase C pathway?
HAVe 1 M&M Gq
H1, alpha1, V1, M1, M3

Phospho C-> PIP2 -> IP3 or DAG
DAG->Protein Kinase C
What receptors are Gs?
Excitatory on Adenylyl cyclase.
B1, B2, D1, H2, V2

Increases cAMP
What receptors are Gi?
Inhibitory of Adenylyl cyclase
M2, A2, D2
What are the different types of Collagen?
Be Cool, Read Books
I- Bone, tendon, skin, dentin, fascia, cornea, late wound repair
II- Cartilage, vitreous body, nucleus puposus
III- Reticulin- skin, blood vessels, uterus, fetal tissue, granulation
IV- Basment membrane
X- epiphyseal plate.
How is collagen synthed?
Inside Fibroblasts
1. Alpha chains (Preprocollagen) made on RER
2. ER- hydroxylation of proline and lysine residues (vit C)
3. Golgi- glycosylation of Pro-alpha-chain lysine residues and formation of procollagen.
4. procollagen are exocytosed
Outside fibroblasts
5. Procollagen peptidases cleave. tropocollagen
6. staggered tropos covalent lysine-hydroxylysine make collagen fibrils.
What is the defect in Ehlers-Danlos?
defect in collagen cross-linking
Hyperextesible skin
bleed easily
hypermobile joints
What is the defect in Osteogenesis imperfecta?
AD disorder in formation of procollagen
1. Multiple fractures
2. Blue sclerae from translucency of the connective tissue over the choroid
3. Hearing loss (bad middle ear)
4. Dental imperfection
What types of cells do the following stain:
Glial fibrillary acid proteins
Vimentin- CT
DesMin- Muscle
CytoKERATIN- Epithelial
Glial FAP- NeuroGLIA
Neurofilaments- Neurons
What is metabolized in the mitochondria, cytoplasm, both?
Mitochondria- Fatty Acid ox, Acetyl-CoA production, Krebs
Cytoplasm- Glycolysis, Fatty synth, HMP shunt, Protein synth, steroid synth
Both- Gluconeogenesis, urea cycle, heme synth

Deck Info