

<!--XBRL document created with Merrill Bridge  6.0.103.0 -->
<!--Based on XBRL 2.1-->
<!--Created on: 11/12/2015 5:02:11 AM-->
<!--Modified on: 11/12/2015 5:02:11 AM-->
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  <xsd:element name="ScheduleOfAccountingPoliciesLineItems" id="glyc_ScheduleOfAccountingPoliciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ScheduleOfAccountingPoliciesTable" id="glyc_ScheduleOfAccountingPoliciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ScheduleOfShareholdersEquityTable" id="glyc_ScheduleOfShareholdersEquityTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="SeriesA1ConvertiblePreferredStockMember" id="glyc_SeriesA1ConvertiblePreferredStockMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestingPeriodNumberOfInstallments" id="glyc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestingPeriodNumberOfInstallments" type="xbrli:integerItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfMaximumSharesIssuedUponExerciseOfIncentiveStockOptions" id="glyc_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfMaximumSharesIssuedUponExerciseOfIncentiveStockOptions" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="instant" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionGrantTerms" id="glyc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionGrantTerms" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ShareholdersEquityLineItems" id="glyc_ShareholdersEquityLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="StockIncentivePlanMember" id="glyc_StockIncentivePlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="TwoThousandThirteenEquityIncentivePlanMember" id="glyc_TwoThousandThirteenEquityIncentivePlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="TwoThousandThreeStockIncentivePlanMember" id="glyc_TwoThousandThreeStockIncentivePlanMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="UnauditedInterimFinancialStatementsPolicyTextBlock" id="glyc_UnauditedInterimFinancialStatementsPolicyTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="UpfrontPaymentRecognitionPeriod" id="glyc_UpfrontPaymentRecognitionPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element id="glyc_ProceedsFromStockOptionsAndWarrantsExercised" name="ProceedsFromStockOptionsAndWarrantsExercised" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="glyc_IncreaseDecreaseInDeferredRent" name="IncreaseDecreaseInDeferredRent" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" xmlns="http://www.w3.org/2001/XMLSchema" />
</xsd:schema>