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  <xs:element name="CorporateBondsMarketableDebtSecuritiesNoncurrentMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_CorporateBondsMarketableDebtSecuritiesNoncurrentMember"/>
  <xs:element name="CorporateBondsPresentedInMarketableDebtSecuritiesMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_CorporateBondsPresentedInMarketableDebtSecuritiesMember"/>
  <xs:element name="CorporateBondsPresentedInMarketableDebtSecuritiesNoncurrentMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_CorporateBondsPresentedInMarketableDebtSecuritiesNoncurrentMember"/>
  <xs:element name="December2024PreFundedWarrantsMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_December2024PreFundedWarrantsMember"/>
  <xs:element name="DecemberPreFundedWarrantMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_DecemberPreFundedWarrantMember"/>
  <xs:element name="DecemberTwoZeroTwoFourPreFundedWarrantsMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_DecemberTwoZeroTwoFourPreFundedWarrantsMember"/>
  <xs:element name="IVCholineChlorideMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_IVCholineChlorideMember"/>
  <xs:element name="InContinuousLossPositionGreaterThanTwelveMonthsMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_InContinuousLossPositionGreaterThanTwelveMonthsMember"/>
  <xs:element name="InContinuousLossPositionLessThanTwelveMonthsMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_InContinuousLossPositionLessThanTwelveMonthsMember"/>
  <xs:element name="OtherResearchAndDevelopmentMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_OtherResearchAndDevelopmentMember"/>
  <xs:element name="PrefundedWarrantsMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_PrefundedWarrantsMember"/>
  <xs:element name="Series1ConvertiblePreferredStockMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_Series1ConvertiblePreferredStockMember"/>
  <xs:element name="SeriesOneConvertiblePreferredStockMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_SeriesOneConvertiblePreferredStockMember"/>
  <xs:element name="StockOptionsMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_StockOptionsMember"/>
  <xs:element name="TARA002InLMsMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_TARA002InLMsMember"/>
  <xs:element name="TARA002InNMIBCMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_TARA002InNMIBCMember"/>
  <xs:element name="TwentySeventeenPlanMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_TwentySeventeenPlanMember"/>
  <xs:element name="TwentyTwentyPlanMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_TwentyTwentyPlanMember"/>
  <xs:element name="TwentyTwentySixATMProgramMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_TwentyTwentySixATMProgramMember"/>
  <xs:element name="TwoZeroTwoFourESPPMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_TwoZeroTwoFourESPPMember"/>
  <xs:element name="TwoZeroTwoFourEquityIncentivePlanMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_TwoZeroTwoFourEquityIncentivePlanMember"/>
  <xs:element name="USTreasurySecuritiesPresentedInMarketableDebtSecuritiesMember" type="dtr:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_USTreasurySecuritiesPresentedInMarketableDebtSecuritiesMember"/>
  <xs:element name="RestrictedStockUnitActivityLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_RestrictedStockUnitActivityLineItems"/>
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  <xs:element name="DocumentAndEntityInformationAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item" id="tara_DocumentAndEntityInformationAbstract"/>
</xs:schema>
