WGUC785 |
Biochemistry
Unit Exam
| |
Q&A |
Latest Version
|
2021/22
|
,WGU C785 Biochemistry Unit Exam
| | | |
Questions
Which |level |of |protein |structure |is |disrupted |through |the |hydrolysis |of |peptide |bonds?
Quaternary
Tertiary
Primary
Secondary
|Answer- |Primary
The |primary |structure |of |a |protein |is |the |sequence |of |amino |acids |held |together |by
|peptide |bonds. |Peptide |bonds |are |formed |by |dehydration |reactions |and |disrupted |by
|hydrolysis.
A |mutation |in |the |beta-hemoglobin |gene, |which |results |in |the |replacement |of |the |amino
|acid |glutamate |in |position |6 |with |the |amino |acid |valine, |leads |to |the |development |of
|sickle |cell |anemia. |The |structures |of |glutamate |and |valine |are |shown |below.
If |the |beta |hemoglobin |gene |in |a |patient |with |sickle-cell |anemia |were |to |be |edited |so |that
|the |valine |in |position |6 |was |replaced |with |a |different |amino |acid, |which |replacement |for
|valine |would |be |expected |to |have |the |best |clinical |outcome, |in |theory, |for |the |patient?
|(Assume |the |valine |can |potentially |be |replaced |with |any |amino |acid |other |than
|glutamate.)
Answer- |The |original |amino |acid |in |a |healthy |patient |is |glutamate, |which |is |negatively
|charged. |The |mutated |amino |acid |is |valine, |which |is |non-polar. |Valine |is |causing |sickle
|cell |anemia. |The |best |amino |acid |to |replace |valine |so |that |the |patient |is |healthy |again
|would |be |the |one |most |like |glutamate, |so |any |negatively |charged |amino |acid.
Secondary, |tertiary, |and |quaternary |levels |of |protein |structure |can |all |be |impacted |by
|exposing |a |protein |to |which |treatment?
Change |of |a |hydrophobic |amino |acid |to |a |different |hydrophobic |amino |acid
Addition |of |a |reducing |agent
Placement |of |the |protein |in |a |solution |with |a |low |pH
Increase |in |the |concentration |of |the |protein |in |solution
, Answer- |Placement |of |the |protein |in |a |solution |with |a |low |pH
Changes |in |pH |affect |hydrogen |bonds |and |ionic |bonds. |Hydrogen |bonds |in |the
|backbone |of |amino |acids |occur |in |secondary |structure, |and |both |hydrogen |bonds |and
|ionic |bonds |occur |in |the |side |chains |of |amino |acids |in |tertiary |structure.
An |increase |in |beta-pleated |sheet |structure |in |some |brain |proteins |can |lead |to |an
|increase |in |amyloid |deposit |formation, |characteristic |of |some |neurodegenerative
|diseases. |What |is |the |primary |biochemical |process |that |follows |the |increase |in |beta-
|pleated |sheet |structure |that |leads |to |the |development |of |the |amyloid |deposits?
An |increase |in |glycogen |formation |in |the |brain |cells
Aggregation |of |the |proteins |in |the |brain
Secretion |of |glucagon, |leading |to |excessive |ketogenesis
An |increase |in |anaerobic |metabolism |of |glucose |in |the |brain
|Answer- |Aggregation |of |the |proteins |in |the |brain
This |question |is |describing |changes |in |protein |structure. |Aggregation |occurs |when
|proteins |clump |together |inappropriately, |causing |plaques |like |amyloid |deposits |to
|accumulate.
Which |level |of |protein |structure |is |determined |by |the |sequence |of |amino |acids?
Secondary |structure
Quaternary |structure
Tertiary |structure
Primary |structure
Answer- |Primary |structure
The |primary |structure |of |a |protein |is |simply |the |sequence |of |amino |acids |held |together |by
|peptide |bonds.
Which |force |is |most |influential |in |determining |the |secondary |structure |of |a |protein?
Hydrophobic |effect
Disulfide |bonding
Hydrogen |bonding
Biochemistry
Unit Exam
| |
Q&A |
Latest Version
|
2021/22
|
,WGU C785 Biochemistry Unit Exam
| | | |
Questions
Which |level |of |protein |structure |is |disrupted |through |the |hydrolysis |of |peptide |bonds?
Quaternary
Tertiary
Primary
Secondary
|Answer- |Primary
The |primary |structure |of |a |protein |is |the |sequence |of |amino |acids |held |together |by
|peptide |bonds. |Peptide |bonds |are |formed |by |dehydration |reactions |and |disrupted |by
|hydrolysis.
A |mutation |in |the |beta-hemoglobin |gene, |which |results |in |the |replacement |of |the |amino
|acid |glutamate |in |position |6 |with |the |amino |acid |valine, |leads |to |the |development |of
|sickle |cell |anemia. |The |structures |of |glutamate |and |valine |are |shown |below.
If |the |beta |hemoglobin |gene |in |a |patient |with |sickle-cell |anemia |were |to |be |edited |so |that
|the |valine |in |position |6 |was |replaced |with |a |different |amino |acid, |which |replacement |for
|valine |would |be |expected |to |have |the |best |clinical |outcome, |in |theory, |for |the |patient?
|(Assume |the |valine |can |potentially |be |replaced |with |any |amino |acid |other |than
|glutamate.)
Answer- |The |original |amino |acid |in |a |healthy |patient |is |glutamate, |which |is |negatively
|charged. |The |mutated |amino |acid |is |valine, |which |is |non-polar. |Valine |is |causing |sickle
|cell |anemia. |The |best |amino |acid |to |replace |valine |so |that |the |patient |is |healthy |again
|would |be |the |one |most |like |glutamate, |so |any |negatively |charged |amino |acid.
Secondary, |tertiary, |and |quaternary |levels |of |protein |structure |can |all |be |impacted |by
|exposing |a |protein |to |which |treatment?
Change |of |a |hydrophobic |amino |acid |to |a |different |hydrophobic |amino |acid
Addition |of |a |reducing |agent
Placement |of |the |protein |in |a |solution |with |a |low |pH
Increase |in |the |concentration |of |the |protein |in |solution
, Answer- |Placement |of |the |protein |in |a |solution |with |a |low |pH
Changes |in |pH |affect |hydrogen |bonds |and |ionic |bonds. |Hydrogen |bonds |in |the
|backbone |of |amino |acids |occur |in |secondary |structure, |and |both |hydrogen |bonds |and
|ionic |bonds |occur |in |the |side |chains |of |amino |acids |in |tertiary |structure.
An |increase |in |beta-pleated |sheet |structure |in |some |brain |proteins |can |lead |to |an
|increase |in |amyloid |deposit |formation, |characteristic |of |some |neurodegenerative
|diseases. |What |is |the |primary |biochemical |process |that |follows |the |increase |in |beta-
|pleated |sheet |structure |that |leads |to |the |development |of |the |amyloid |deposits?
An |increase |in |glycogen |formation |in |the |brain |cells
Aggregation |of |the |proteins |in |the |brain
Secretion |of |glucagon, |leading |to |excessive |ketogenesis
An |increase |in |anaerobic |metabolism |of |glucose |in |the |brain
|Answer- |Aggregation |of |the |proteins |in |the |brain
This |question |is |describing |changes |in |protein |structure. |Aggregation |occurs |when
|proteins |clump |together |inappropriately, |causing |plaques |like |amyloid |deposits |to
|accumulate.
Which |level |of |protein |structure |is |determined |by |the |sequence |of |amino |acids?
Secondary |structure
Quaternary |structure
Tertiary |structure
Primary |structure
Answer- |Primary |structure
The |primary |structure |of |a |protein |is |simply |the |sequence |of |amino |acids |held |together |by
|peptide |bonds.
Which |force |is |most |influential |in |determining |the |secondary |structure |of |a |protein?
Hydrophobic |effect
Disulfide |bonding
Hydrogen |bonding
