Biochemistry: Thyroid Hormones Multiple Choice Questions PDF

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Summary

The following are thyroid hormones: TRH – TSH – T 3 and T 4 a) True b) False -----causes increased metabolism, whereas ----causes decreased metabolism. a) Hypothyroidism b) Hyperthyroidism Weight gain and cold intolerance are seen in ----. Whereas, sweating, weight loss and heat intolerance are seen...

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Thyroid(Hormones( The(following(are(thyroid(hormones:( TRH(–(TSH(–(T3(and(T4( a) True( b) False( ( -----causes(increased(metabolism,(whereas(----causes(decreased(metabolism.( a) Hypothyroidism( b) Hyperthyroidism( ( Weight(gain(and(cold(intolerance(are(seen(in(----.(Whereas,(sweating,(weight(loss(and(heat( intolerance(are(seen(in(-----.( a) Hypothyroidism( b) Hyperthyroidism( ( Basal(Metabolic(Rate((BMR)(is(a(measure(of(the(number(of(kilojoules(your(body(will(burn(on( any(given(day,(without(taking(into(account(any(exercise(you(may(do.((( ( ----reduces(the(basal(metabolic(rate((BMR),(whereas,(----increases(the(BMR.( a) Hypothyroidism( b) Hyperthyroidism( ( ----could(be(associated(with(a(deficiency(in(LPL(activity.(As(a(consequences,(------could(be( elevated.( a) Hypothyroidism( b) Hyperthyroidism( c) LDL(and(VLDL( d) HDL( ( Goiter(and(cretinism(are(both(happening(due(to(lack(of(-------( a) Calcium( b) Copper( c) Iodine( d) Iron( e) Potassium( ( ( Which(of(the(following(autoantibodies(is(most(commonly(associated(with(Hashimoto’s( disease?( a) Anti(TSH(receptor(antibodies( b) Anti(TPO(antibodies( c) Anti(TBG(antibodies( d) Anti(thyroglobuin(antibodies( ( are(formed(during(the(organification(of(thyroglobulin,(whereas(-------are(formed(during(the( coupling(of(iodotyrosine.( a) T1(&(T2( b) T3(&(T4(

Thyroid(Hormones( c) T1(&(T3( d) T2(&(T4( e) T1(&(T4( ( Which(of(the(following(thyroid(hormones(has(the(highest(biological(activity?( a)T4( c)T3( d)rT3( ( Which(of(the(following(thyroid(hormones(is(more(abundant?( a)(T4( b)(T3( c)(rT3( ( Thyroxine(is(----,(which(is(converted(to(the(more(active(form,(----,(when(the(target(tissues( need(it.( a)(T4( b)(T3( c)(rT3( ( T3(and(T4(are(synthesized(in(4(phases(as(follows:( i. The(follicle(cells(released(tyrosine,(which(forms(iodothyronine(1(&(2((thyroglobulin)( via(organification((TPO)( ii. Release(of(iodide(from(the(plasma(into(the(follicle(cells( iii. Lysosomes(digested(thyroglobulin(and(released(T3(and(T4( iv. Joining(of(T1(to(T2(and(T2(to(T2(to(form(T3(and(T4,(respectively((inside(thyroglobulin( (Coupling)( The(right(arrangement(is( a) i-ii-iii-iv( b) ii-i-iv-iii( c) iii-i-iv-ii( d) ii-iii-i-iv( e) iv-i-iii-ii( ( Sodium-iodide(symporter(transfers(two(sodium(and(one(iodide(from(the(plasma(to(the( follicle(cells.(Iodide(binds(to(thyroglobulin(to(form(-----.(T3(is(formed(from(coupling(of(----,( whereas(T4(is(formed(from(coupling(of(-----.(( a) T1( b) T2( c) T1(to(T2( d) T2(to(T2( e) T1(and(T2( ( ( ( ( (

Thyroid(Hormones( Oxidation(of(iodide(ions,(I-,(to(nascent(iodine,(I0,(or(I3-(is(promoted(by(-----(( a) Ligase( b) Tyrosine( c) Peroxidase( d) Trypsine( ( Organification(of(thyroglobulin(is(the(binding(of(oxidized(----to(thyroglobulin(to(form(T1(and( T2.(( a) Amine( b) Bromine( c) Chlorine( d) Iodine( ( -------is(the(enzyme(responsible(for(iodination(of(tyrosine(to(monoiodotyrosine((T1)(and(then( to(diiodotyrosine((T2).(( a) Hydrolase( b) Ligase( c) Peroxidase( d) Thyroid(peroxidase((TPO)(( e) Tyrosinase( ( In(thyroid(hormones(synthesis,(if(T1(binds(to(T2(it(forms(----,(whereas(if(T2(binds(to(T1,(it( forms(-----.(( a) T1( b) T2( c) T3( d) rT3( e) T4( ( Iodine(is(present(in(low(concentration(in(plants(growing(on(mountains.(Thus(inhabitants(of( mountains(need(to(have(supplement(intake(of(iodine((e.g.(---)(to(compensate(the(loss(of( iodine(in(their(foods.( a) Iodized(table(salts( b) Table(salts( c) Sodium(chloride( ( Does(excess(iodine(intake(is(dangerous(to(your(body?(---,(as(it(will(------.( a) Be(excreted(in(urine( b) Cause(hyperthyroidism( c) No( d) Yes( ( Thyroxine(is(converted(to(T3(by(the(aid(of(the(enzyme:(( a) Tyrosine(peroxidase((TPO)( b) De-iodinase( c) Trypsin( d) Lipase(

Thyroid(Hormones( ( About(93(per(cent(of(the(thyroid(hormones(released(from(the(thyroid(gland(is(normally(------,(only(7(per(cent(is(------------.(( a) T1( b) T2( c) T1(and(T2( d) T3( e) T4( ( The(active(form(of(iodothyronine(is--(( a) T1( b) T2( c) T1(and(T2( d) T3( e) T4( In(the(blood(circulation,(T3(and(T4(bind(to(all(the(following(EXCEPT( a) Albumin( b) Plasma(proteins(( c) Thyroxin-binding(Globulin((TBG)( d) Thyroxin-binding(prealbumin( e) Mono-(and(di-iodothyronine( ( Which(of(the(following(thyroid(hormones(has(the(highest(biological(activity?( a) T1( b) T3( c) T4( d) rT3( e) TSH(receptor(antibodies( ( Regulation(of(thyroid(hormones(is(based(on( a) Free(T4(and(T3( b) Bound(T4(and(T3( c) Total(T4(and(T3( ( Thyroxine-binding(globulin((TBG)(is(a(globulin(that(binds(thyroid(hormones(in(circulation.(It( is(one(of(three(transport(proteins((along(with(transthyretin(and(serum(albumin)(responsible( for(carrying(the(thyroid(hormones(thyroxine((T4)(and(triiodothyronine((T3)(in(the( bloodstream.( a) True( b) False( ( At(------liver(disease,(the(hormone(binding(factor,(thyroxine(binding(globulin((TBG),(is( normally(elevated,(whereas(at(------liver(disease,(it(is(normally(decreased.( a) Early( b) Late( (

Thyroid(Hormones( Thyroxine-binding(globulin((TBG)(is(a(globulin(that(binds(thyroid(hormones(in(circulation.(It( is(one(of(three(transport(proteins((along(with(transthyretin(and(serum(albumin)(responsible( for(carrying(the(thyroid(hormones(thyroxine((T4)(and(triiodothyronine((T3)(in(the( bloodstream.( a) True( b) False( ( At(------liver(disease,(the(hormone(binding(factor,(thyroxine(binding(globulin((TBG),(is( normally(elevated,(whereas(at(------liver(disease,(it(is(normally(decreased.( a) Early( b) Late( ( T4(is(converted(to(the(active(form(T3(in(the(-----.(Then(T3(diffuses(to(the(-----and(binds(to( thyroid(hormone(receptor((THR),(which(binds(to(the(thyroid(response(element((TRE)(and( initiate(transcription(and(translation.( a) Colloid( b) Cytosol( c) Nucleus( d) Plasma( ( The(thyroid(hormone(T3(diffuses(to(the(nucleus(and(binds(to(the(-----,(which(binds(to(the(-----and(initiate(transcription(and(translation.( a) Thyroid(hormone(receptor((THR)( b) Thyroid(response(element((TRE)( c) Thyroxine(binding(globulin((TBG)( ( How$T3$and$T4$secretion$are$regulated?( When(there(is(a(deficiency(of(T3(and(T4,(the(hypothalamus(stimulates(the(production(of(----,(which(stimulates(the(anterior(pituitary(gland(to(produce(-----,(which(stimulates(the(thyroid( gland(to(produce(T3(and(T4.(Excess(T3(and(T4(are(-----(for(TRH(and(TSH.( a) TRH( b) TSH( c) Negative(feedback/inhibitors( d) Positive(feedback/stimulators( ( TRH(is(produced(by(the(-----and(it(is(downregulated(by(-----.( a) Anterior(pituitary(gland( b) Hypothalamus( c) T1(and(T2( d) T2(and(T3( e) T3(and(T4( TSH(is(produced(in(the(-----and(it(is(downregulated(by(----.( a) Hypothalamus( b) Anterior(pituitary(gland( c) T3( d) T4( (

Thyroid(Hormones( ( With(respect(to(thyroid(gland:(A(disease(in(the(thyroid(gland(is(termed,(----disease,(whereas,( a(disease(in(the(hypothalamus/pituitary(gland(that(affects(the(thyroid(gland(is(termed,(---( disease.( a) Primary( b) Secondary( ( Graves$disease:( Which(of(the(following(autoantibodies(is(most(commonly(associated(with(Grave's(disease?( a) Anti(TSH(receptor(antibodies( b) Anti(TPO(antibodies( c) Anti(TBG(antibodies( d) Anti(thyroglobuin(antibodies( ( ( The(most(common(cause(of(hyperthyroidism(is(which(of(the(following?( a) Hashimoto's( b) Toxic(adenoma(of(the(thyroid( c) Grave's( d) Iodine(excess( ( In#----,#anti#TSH#receptor#antibodies((TSI)(binds(and(stimulates(the(TSH(receptor((on(the( thyroid(gland).(Accordingly,(T3(and(T4(are(elevated,(whereas(TSH(declines(via(negative( feedback/(inhibition.( a) Hashimoto's(disease( b) Toxic(adenoma(of(the(thyroid( c) Grave's(disease( d) Iodine(excess( ( The(most(common(cause(of(hypothyroidism(is(which(of(the(following?( a) Hashimoto's( b) Toxic(adenoma(of(the(thyroid( c) Grave's( d) Iodine(excess( ( Which(of(the(following(plasma(values(best(represents(the(biochemical(picture(for(a(patient( with(Hashimoto's(disease?( a) Decreased(TSH(+(elevated(T4( b) Decreased(TSH(+(decreased(T4( c) Increased(TSH(+(decreased(T4( d) Normal(TSH(+(elevated(T4( e) Normal(TSH(+(decreased(T4( ( ( ( (

Thyroid(Hormones( Which(of(the(following(autoantibodies(is(most(commonly(associated(with(Hashimoto’s( disease?( a) Anti(TSH(receptor(antibodies( b) Anti(TPO(antibodies( c) Anti(TBG(antibodies( d) Anti(thyroglobuin(antibodies( ( The(front(line(tests(for(diagnosis(in(measurement(of(serum(thyroid(hormone(levels(are(-------( a) T3(and(TSH( b) T3(and(TRH( c) T4(and(TSH( d) T4(and(TRH( e) T3(and(T4( ( What(is(the(general(structural(characteristics(of(steroid(hormones?( a) 1(Six(carbon(ring(+(3(five(carbon(rings( b) 2(Six(carbon(rings(+(2(five(carbon(rings( c) 3(Six(carbon(rings(+(1(five(carbon(ring( d) 3(Six(carbon(rings(+(3(five(carbon(rings( e) 5(Six(carbon(rings(+(1(five(carbon(ring( ( Which(of(the(following(is(NOT(among(the(steroid(hormones?( a) Glucocorticoids( Mineralocorticoids( b) Progestogens((progesterones)(( c) Sex(Steroids(( d) Vitamin(D( e) T3(&(T4(( ( ( What(is(the(starting(compound(for(the(synthesis(of(all(steroid(hormones?( a) Cortisol( b) Progesterone( c) Estradiol( d) Pregnenolone( e) Testosterone( ( What’s(the(most(abundant(circulating(steroid(hormone(in(humans?(It(is(--------.(Why(it(is( important(to(human?(It(functions(predominantly(as(a(metabolic(intermediate(in(the(------(of( the(androgen(and(estrogen(sex(steroids.(( a) Didehydroepiandrosterone((DHEAS)(( b) Biosynthesis( c) Catabolism( d) Pregnenolone( (

Thyroid(Hormones( In(women,(---------(as(a(sex(hormone(is(more(abundant(than(men,(whereas,(--------(is(more( abundant(in(men(than(women.(On(the(other(hand,(---------hormone’s(concentration(is( doubled(in(men(than(women.( a) Didehydroepiandrosterone((DHEAs)(( b) Progesterone( c) Testestorone( ( What(dictates(whether(a(tissue(responds(to(steroid(hormones(or(not?( Some(tissues(have(----which(can(metabolize(hormones,(whereas(others(need(-----(for( hormonal(response.( a) Enzymes( b) Proteins( c) Steroid(receptors( ( What(dictates(whether(a(tissue(responds(to(steroid(hormones(or(not?( -----and(enzyme(profile,(for(example,(------(is(required(for(aldosterone(synthesis(only(found( in(------((outer(zone)(of(adrenal(cortex.( a) Aldosterone( b) Hormone(receptors( c) Progesterone( d) 18-hydroxylase( e) zona(glomerulosa(cells( ( In(general,(androgens(are(considered(“-----sex(hormones",(while(estrogens(and( progestogens(are(considered(“-----sex(hormones"(although(all(types(are(present(in(each(sex,( albeit(at(different(levels.( a) Female( b) Male( ( The(following(are(male(sexual(development(steroid(hormones(EXCEPT( a) Androgens( b) Didehydroepiandrosterone(( c) Progesterone( d) Testosterone( ( The(source(of(androgens(in(men(is(in(the(----,(whereas,(it(is(in(the(---in(women.( a) Ovary( b) Peripheral(tissues( c) Testis( ( The(following(are(female(sexual(development(steroid(hormones(EXCEPT( a) Androgens( b) Oestrogens( c) Progesterone( d) Estradiol( ( (

Thyroid(Hormones( The(source(of(oestrogens(in(men(is(in(the(---------,(whereas,(it(is(in(the(----in(women.( a) Ovary( b) Peripheral(tissues( c) Testis( ( What(is(the(female(steroid(hormone(that(is(required(for(maintenance(of(pregnancy?( a) Androgens( b) Cortisol( c) Estradiol( d) Progesterone( e) Pregnenolone( ( What(is(the(mineralocorticoid(hormone(that(stimulates(Ç(reabsorption(of(Na+(in(exchange( for(excretion(of(K+(and(H+?( a) Aldosterone( b) Androgens( c) Estradiol( d) Progesterone( e) Pregnenolone( ( What(is(the(major(stress(hormone(and(it(is(in(the(group(of(glucocorticoid?( a) Androgens( b) Cortisol( c) Estradiol( d) Progesterone( e) Pregnenolone( ( People(tend(to(-------weight(when(they(are(stressed(and(that(due(to(increase(of(the(hormone( ---------?( a) Gain( b) Loose( c) Androgens( d) Cortisol( e) Estradiol( ( According(to(Circadian(release(of(------,(it(is(recommended(to(do(work(in(the(early(morning.( a) Androgens( b) Cortisol( c) Estradiol( d) Progesterone( e) Pregnenolone( ( Cortisol(level(is(-----in(the(early(morning(and(tends(to(be(------(at(the(time(of(sleep(onset.( Loss(of(cortisol(circadian(rhythm(is(associated(with(adrenal(insufficiency(and(death.( a) High( b) Low( (

Thyroid(Hormones( In(case(of(injury,(fear,(or(anxiety,(the(corticotrophin(releasing(hormone((CRH)(is(firstly( synthesized(in(the(----as(a(response(to(stress.(CRH(is(positively(stimulated(the(-----to( synthesize(the(adrenocortropic(hormone((ACTH),(which(finally(stimulates(the(----to( synthesize(the(cortisol.(However,(this(process(is(regulated(by(negative(feedback(when(the( hormone(------is(high(in(concentration.( a) Aldosterone( b) Adrenal(cortex(( c) Anterior(pituitary(gland( d) Cortisol( e) Hypothalamus(( ( The(hormones(that(stimulate(secretion(of(other(hormones(are(called:(-----(hormones.( a) Androgens( b) Cortisol( c) Estradiol( d) Progesterone( e) Trophic( ( As(examples(of(----hormones,(adrenocorticotrophic(hormone((ACTH)(stimulates(----,( whereas(------stimulates(testestorone/oestrogens,(and(-----(stimulates(oestrogens.( a) Androgens( b) Cortisol( c) follicle(stimulating(hormone((FSH)( d) lutheinising(hormone((LH)( e) Trophic( ( The(hormone(-----(is(not(stimulated(by(the(pituitary(hormones((trophic(hormones).( a) Aldosterone( b) Cortisol( c) Oestrogens( d) Testosterone( e) Progesterone( ( ( As(a(response(of(a(pathogen(attack,(the(body(started(inflammations(to(attack(the(pathogen.( However,(chronic(inflammation(is(a(disease(and(needs(to(be(stopped.( ( Steroid(hormones(are(water(--------.(Thus(need(a(protein(carrier(to(transport(them(in(the( plasma(to(the(different(cell(membranes.(( a) soluble( b) Insoluble( ( Increase(or(decrease(of(gene(transcription(or(mRNA(synthesis(is(regulated(by(steroid( hormones.(( a) True( b) False( (

Thyroid(Hormones( Cortisol(and(aldosterone(bind(to(their(receptors(----the(nucleus,(whereas(oestradiol(and( progesterone(hormones(bind(to(the(receptors(-----the(nucleus.( a) Inside( b) Outside( ( Steroid-receptor( complexes(aggregate(into(-----and(are(said(to(be(-----.( a) Homodimers( b) Homotrimers( c) Activated( d) Deactivated( ( The(unoccupied(hormone(receptors(are(bound(to(heat(shock(protein(to(----the(binding(of( receptors(to(DNA(and(to(-----the(receptor(is(in(the(right(conformation.( a) Make(sure(( b) Prevent( ( The(receptor(homodimers(hormone(bind(to(the(----,(which(in(turn(bind(to(both(the(TATA( binding(protein(and(the(------to(synthesise(a(new(protein.( a) Activators( b) Co-activators( c) DNA(polymerase( d) Kidney( e) RNA(polymerase( ( ( The(gene(transcription(to(produce(interleukin((IL6)(during(inflammation(is(activated(by( _____(and(inhibited(by(the(influence(of(_________(( a) ACTH(( b) Glucocorticoids( c) NFkβ( ( Plasma(and(ECF(have(both(bound(and(free(forms(of(steroid(hormones.(The(free-hormone(is( the(_____(form.( a) Active( b) Inactive( ( -------have(both(bound(and(free(forms(of(steroid(hormones.(The(bound-hormone(are( homrones(bound(to(sex(hormone(binding(globulin((SHBG),(cortisol(binding(globulin((CBG)( and(albumin.( a) ECF(and(ICF( b) ECF(and(plasma( c) ICF(and(plasma( ( (...