Chapter 4: Protein Structure and Function Flashcards
When a carboxyl group of the amino acid on the left attaches to the amino group of another AA on the right what does it make?
peptide bond
What is the difference between small proteins and large proteins in gel electrophoresis?
small proteins migrate further
large proteins stay closer to the start site
How does acidosis affect our bodies?
- denatures proteins
- hyperkalemia
3.Kussmaul breathing
4.more GABA
Which is the only enzyme that cuts to the left?
carboxypeptidase
Which enzyme cuts to the right of LYS and ARG?
Trypsin (trippin in LA)
Which enzyme cuts to the right of PHE, TRP, TYR
chymotripsin
Which enzyme cuts to the right of GLY, ALA, SER
Elastase (GAS to “last”)
Which cuts to the right of MET?
CNBr
Which enzyme cuts tot he right of the amino terminal amino acid?
Aminopeptidase
Which enzyme can break disulfide bonds?
Mercaptoethanol
Name two acute phase reactants?
CRP and ESR
What is the best test to detect excess protein in the serum during infections?
PROCALCITONIN
Which cells make acute phase reactants?
T cells and macrophages
Non specific deposition of acute phase reactants?
Amyloidosis
Diagnosis of Acute Amyloidosis
apple green birefrigence on Congo red stain
Amyloid alpha in developing countries?
chronic infection
Amyloid alpha in developed countries?
RA,SLE,IBD
Alpha Beta amyloidosis are found in which groups?
Downs syndrome and Alzheimer pts
Which betalipoprotein is most common in Alzheimers?
Betalipoprotein E4
What are neurofibrillary tangles of Alzheimers?
oxidized proteins building up
What is the main amyloid in Alzheimers?
Amyloid Precursor protein (APP)
What vitamin can you give Alzheimer patients to prevent oxidation of the proteins?
Vitamin E
Which amyloid is associated with renal failure?
AB-2
Which amyloid is associated with MEN2?
AE and AF
Which amyloid is associated with Multiple Myeloma?
AL L is for light chains (Bence Jones proteins in urine)
Which amyloid is associated with aging?
transthyretin
When two or more proteins are interacting with each other it is called
cooperativity
When two or more enzymes are cooperating it is called
allosterism (the allosteric enzyme is the rate limiting enzyme because it controls everything)
When substrate concentration no longer affects Vmax, all the binding sites are filled up, this is called
zero order elimination
first order elimination
proportion or percent eliminated per hour
When something says eliminates a set amount every hour that is
zero order elimination
examples of drugs that are zero order
alcohol, aspirin, phenytoin
When half the enzyme’s active sites are occupied by drug that is called
Km Km=1/2Vmax
What is the main difference between competitive and noncompetitive inhibitors?
Competitive inhibitors bind to the same site, the Km increases and the Vmax stays the same; noncompetitive inhibitors bind to different (allosteric) sites, Vmax decreases and Km stays the same.
Name an organ where you will find the lowest Km for any substrate (highest affinity or potency)?
brain
Which hemoglobin has 2 alpha-2beta chains?
HbA (adult)
Which hemoglobin has 2 alpha-2 delta?
HbA 2 (2% normal)
Which hemoglobin has 2 alpha-2 gamma chains?
HbF (fetal)
Which hemoglobin doesn’t like to drop off it oxygen?
HbF
What does hydroxyurea do in sickle cell pts?
induces more HbF
What is right shift of the oxygen hemoglobin dissociation curve mean?
It means hemoglobin willing to give up oxygen because hypoxia, acidosis, high altitude, increase in 2,3 BPG, or increase in temperature
What does left shift mean?
Hemoglobin less willing to give up oxygen because increase in HbF, CO, or Met hemoglobin.
When you are exercising, you have created a right shift, and if you keep pushing the body to oxygenate, you will force HbF and myoglobin to desaturate and give their oxygen, this is called?
second wind
When CPK leaks out of a muscle it is called?
myositis
What are the top reasons for myositis?
- hypothyroidism 2. Cushings 3. drugs (statin, INH, rifampin, steroids) 4. infection i.e. taenia solium from raw pork
What is a reserve source of energy in muscle called?
myoglobin
Will acidosis shift the curve to left or right?
right
How can you tell an athlete is blood doping?
high hemocrit, low EPO
What is the antibody for Dermatomyositis?
anti-Jo
What is the antibody for polymyositis?
anti-Jo
labs in polymyositis?
up CPK, up LDH, up aldolase, up AST and ALT
Where can erythropoiesis take place before 1 year of age?
liver, spleen, flat bones
If you lose bone marrow function after 1 year old, which organ can take over erythropoeisis?
spleen (massive splenomegaly)
Does synthesis take place in cytoplasm or mitochondria?
cytoplasm
Does catabolism (breaking down) take place in cytoplasm or mitochondria?
mitochondria
What is the exception to sythesis in cytoplasm rule?
glycolysis, breaks down in cytoplasm because it must feed into other pathways
5 pathways that occur in both cytoplasm and mitochondria:
- heme synthesis
- gluconeogenesis
- urea cycle
- fatty acid synthesis
- pyrimidine synthesis
What is the rate limiting enzyme for heme sythesis?
D-ala sythase
What is it called when iron on hemoglobin is in Fe3+ state?
methemoglobinemia
What is the treatment for methemoglobinemia?
methylene blue
What is the treatment for cyanide poisoning?
amylnitrite to change iron to Fe3+ and bind cyanide
most common causes of methemoglobinemia?
1.infection (free radicals made by neutrophil NADPH oxidase)
2. sulfa drugs
What is the treatment for cyanide poisoning?
amylnitrite to change iron to Fe3+ and bind cyanide; B12 to bind cyanide and excrete through kidneys, methylene blue to reduce iron back to Fe2+, transfuse with fluids
MCC of microcytic hypochromic anemia
Iron deficiency (poor diet) in ages 0-20; in ages 20-40 IBD; in ages greater than 40 mucosal bleeding; administer iron with vitamin C to protect in GI and vitamin E to protect in blood
How is the Serum Fe and saturated Fe and Ferritin (stored iron) in iron deficiency?
all low
What is the most common IBD in middle aged pts?
CrohnsWhat
What is the main difference between iron deficiency anemia and anemia of chronic disease?
Anemia of chronic disease the Ferritin is high because the iron is sequestered; iron deficiency the Ferritin is low because of low intake or high loss.
Which lab shows lead poisoning?
FEP free erythrocyte protoporphyrins
What is drug for moderate lead poisoning?
Succimer
What is drug for severe lead poisoning?
EDTA, Dimercaprol (BAL) and/or penicillamine
EDTA treatment leads to deficiency of these 5 minerals?
Ca, Fe, Pb, Cu, Mg (any metal with 2+)
Enzyme deficiency in Porphyria Cutanea Tarda
uroporphyrinogen decarboxylase
Tx for Porphyria Cutanea Tarda
stay away from direct sunlight, use red/blue light, need blood transfusions, vita D deficiency, phlebotomy if necessary, anti-malarials (low dose ( removes excess porphyrins from liver)
Which enzyme is deficient in Acute Intermittent Porphyria (AIP)
uroporphyrinogen 1 synthase
5 P’s of AIP
pain (abd), polyneuropathy, psychological abnormalities, pink urine, precipitated by drugs (alcohol, barbs, OCP)
treatment for AIP
opiates for pain, IV normal saline, clucose to bilirubin conjugate to help excrete from liver faster, hematin to block d-ala-synthase to decrease synthesis of rings
signs of opiate withdrawal
cramps, diarrhea, excessive urination and piloerection
What is the genetic problem with sickle cell anemia?
glutamic acid (neg.charge and water soluble) into valine (neutral, fat-soluble) at position 6 of beta chain
What is the risk for any disease in general population? with one factor? with two factors
1-3%; one factor, 10%; two factors, more than 20%
In sickle cell patients, always check reticulocyte count, why?
Make sure bone marrow is working
What happens to spleen of sickle cell patients?
self asplenectomy by age 6 due to infarcts
What kind of organisms are sickle cell patients susceptible to?
encapsulated organism Some Killers Have Nice Capsules Salmonella, Strep Pneumo, Hib, N. Meningiditis, need pneumo vaccine before age 2
What is it called when one alpha gene missing in hemoglobin?
alpha thalassemia minor
What is it called when all four alpha genes are missing?
alpha thalassemia major (incompatible with life)
What is it called when one Beta gene is missing?
Beta thalassemia minor
What is it called when two beta genes are missing from hemoglobin?
beta thalassemia major; need transfusions, can make HbA2 and HbF; transfusion dependent after 6 months of age
How much more will hemoglobin raise if given 1 unit of packed red blood cells + one unite of FFP+ 1 unit of plts?
1-2 grams (3-6HCT)
What is TRALI (transfusion related acute lung injury) caused by?
release of cytokines, causes ARDS, treat with steroids
What can you get from too many transfusions?
Iron overload; hemosiderosis; hemochromatosis, skin bronzing, restrictive cardiomyopathy and arthritic pain in joints
DOC for iron overload
deferoxamine, or EDTA-BAL)
4 types of collagen
SCAB
Type 1-Skin
Type 2- Connective tissue
Type 3-Arteries
Type 4-basement membrane
What is collagen made of (3 AA, 1 vitamin, 1 mineral)
glycine, proline, lysine , Vita C and Cu
What is the only protein completely modified in the RER?
collagen
What is the only modification that can go on in the RER?
N-acetylation (adding acetly group onto N)
What is the chaperone to the Golgi?
HSP-90
If mannose 6 phosphate is added in the Golgi, where will the protein be directed to?
lysosome
In which disease is there a mannose 6 phospate deficiency, proteins are excreted into plasma and lysosomes are empty?
I cell disease
What is the chaperone from RER to mitochondria?
HSP-70
Which disease involves collagen type 1 and shows multiple bone fractures from birth?
Osteogenesis imperfecta (OI)
What does CREST stand for in CREST syndrome?
Calcinosis cutis (calcium deposits in skin)
Raynaud’s (finger turn blue then white, then red
Esophageal immotility
sclerodactyly
telangiectasias
What is the antibody involved in CREST?
anti-centromere antibodies
Which antibody is involved in scleroderma?
anti-smooth muscle antibodies; anti-SCL 70;
Which antibody is involved in progressive systemic sclerosis?
anti-topoisomerase antibody
What is the most sensitive antibody in Rheumatoid Arthritis?
Anti cyclic citrullinated peptide (CCP antibody)
What is the treatment for moderate to severe arthritis?
methotrexate, within 90 days add TNF inhibitor (imatinib)
What antibodies are seen in Sjorgen’s syndrome?
anti-Ro, anti-La, SSA, SSB antibodies
4 bad associations of cardiolipin antibody:
stimulates intrinsic clotting system
blocks vWF
multiple spontaneous abortions
false positive VDRL
antibodies of SLE
anti-Smith, anti dsDNA, anti cardiolipin
Tx for SLE
mycophenalate; steroids
drug induced lupus commonly caused by
HIPPPI
hydralazine
INH
procainamide
penicillamine
phenytoin
ethosuximide
Lupus + RA
mixed connective tissue disease, ribonuclear protein antibody (anti-RNP)
What are neutropenic, burn pt, CF pts, and diabetics afraid of?
staph Aureus and pseudomonas
tx for staph Aureus
vancomycin
Tx for pseudomonas
2 antibiotics; i.e. piperacillin/tazo; ceftazidine/avibactim; aminoglycoside+betalactam