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Bio 2B03 Review
** 100% Guaranteed Pass
** Expert-Verified Explanation
** Questions with Verified Answer
** New Edition | 2026-2027 Updated
,is the RER dynamic or stationary? dynamic
what is the function of the RER? co-translational transport, protein modification, formation of vesicles that will
transport proteins from ER to Golgi
what is the function of the SER? fatty acid and phospholipid synthesis, carbohydrate metabolism, regulate Ca2+
conc in the cytosol
what are the post translational modifications in the ER? - glycosylation
- protein folding
- disulphide bond formation
- proteolytic cleavage
do modifications to proteins embedded in the ER luminal
membrane occur in the luminal portion or the
transmembrane domain or the cytosolic portion?
this protein modification is important for proteins that glycosylation
mediate cell interactions with the extracellular matrix and
for receptor-ligand recognition
this protein modification is common on proteins that are glycosylation
secreted from the cell and proteins embedded in the cell
membrane
what is the most common form of glycosylation? N-linked
N-linked glycosylation adds a polysaccharide to which NH2 group of the R-group of asparagine
group of which amino acid?
these proteins recognize modified proteins and assist in lectins
protein folding in a similar way as chaperones
what are the two types of lectins? calnexin and calreticulin
where is calnexin found? ER membrane
what is BiP? mention 3 functions - ER-resident HSP70 chaperone
- transfers proteins from ER through the translocon by binding to proteins as
soon as they appear on the luminal side of the membrane during co-translational
transport
- initiate unfolded protein response in the ER
what are the co-chaperones of BiP? Hsp40 and NEF
is cytoplasm a reducing or an oxidizing environment? reducing
, is ER a reducing or an oxidizing environment? oxidizing
does disulphide bond formation occur in reducing or oxidizing
oxidizing environment?
this protein is one of many proteins secreted into the RNAse A
intestine where it aids in the digestion of RNA by
cleaving it into small pieces
what is the protein that resides in the ER that promotes protein disulphide isomerase (PDI)
oxidation?
does proteolytic cleavage in the ER happen in the lumen lumen
or the cytosol?
what is the N-terminal signal sequence of type I integral signal peptidase
proteins cleaved by?
what are the two responses of the unfolded protein 1. restore normal cell function by slowing down new protein translation or
response (UPR)? removing unfolded proteins from the ER for degradation through ubiquitylation
2. increase production of chaperones
what are the proteins essential to UPR? BiP and Ire1
this protein is involved in the UPR and functions as a BiP
chaperone to assist in proper folding and prevent
aggregation of misfolded proteins
this is a transmembrane protein that is involved in the Ire1
UPR
Ire1 endonuclease specifically targets which gene's Hac1
mRNA?
what does unspliced Hac1 do? inhibit translation
this protein is a transcription factor that activates Hac1
transcription of several genes including the genes that
code for BiP, lectins, PDI, and signal peptidases
where is the Hac1 protein transported to? nucleus
moving from the ER towards the cell membrane anterograde
moving from the cell membrane towards the ER retrograde
Bio 2B03 Review
** 100% Guaranteed Pass
** Expert-Verified Explanation
** Questions with Verified Answer
** New Edition | 2026-2027 Updated
,is the RER dynamic or stationary? dynamic
what is the function of the RER? co-translational transport, protein modification, formation of vesicles that will
transport proteins from ER to Golgi
what is the function of the SER? fatty acid and phospholipid synthesis, carbohydrate metabolism, regulate Ca2+
conc in the cytosol
what are the post translational modifications in the ER? - glycosylation
- protein folding
- disulphide bond formation
- proteolytic cleavage
do modifications to proteins embedded in the ER luminal
membrane occur in the luminal portion or the
transmembrane domain or the cytosolic portion?
this protein modification is important for proteins that glycosylation
mediate cell interactions with the extracellular matrix and
for receptor-ligand recognition
this protein modification is common on proteins that are glycosylation
secreted from the cell and proteins embedded in the cell
membrane
what is the most common form of glycosylation? N-linked
N-linked glycosylation adds a polysaccharide to which NH2 group of the R-group of asparagine
group of which amino acid?
these proteins recognize modified proteins and assist in lectins
protein folding in a similar way as chaperones
what are the two types of lectins? calnexin and calreticulin
where is calnexin found? ER membrane
what is BiP? mention 3 functions - ER-resident HSP70 chaperone
- transfers proteins from ER through the translocon by binding to proteins as
soon as they appear on the luminal side of the membrane during co-translational
transport
- initiate unfolded protein response in the ER
what are the co-chaperones of BiP? Hsp40 and NEF
is cytoplasm a reducing or an oxidizing environment? reducing
, is ER a reducing or an oxidizing environment? oxidizing
does disulphide bond formation occur in reducing or oxidizing
oxidizing environment?
this protein is one of many proteins secreted into the RNAse A
intestine where it aids in the digestion of RNA by
cleaving it into small pieces
what is the protein that resides in the ER that promotes protein disulphide isomerase (PDI)
oxidation?
does proteolytic cleavage in the ER happen in the lumen lumen
or the cytosol?
what is the N-terminal signal sequence of type I integral signal peptidase
proteins cleaved by?
what are the two responses of the unfolded protein 1. restore normal cell function by slowing down new protein translation or
response (UPR)? removing unfolded proteins from the ER for degradation through ubiquitylation
2. increase production of chaperones
what are the proteins essential to UPR? BiP and Ire1
this protein is involved in the UPR and functions as a BiP
chaperone to assist in proper folding and prevent
aggregation of misfolded proteins
this is a transmembrane protein that is involved in the Ire1
UPR
Ire1 endonuclease specifically targets which gene's Hac1
mRNA?
what does unspliced Hac1 do? inhibit translation
this protein is a transcription factor that activates Hac1
transcription of several genes including the genes that
code for BiP, lectins, PDI, and signal peptidases
where is the Hac1 protein transported to? nucleus
moving from the ER towards the cell membrane anterograde
moving from the cell membrane towards the ER retrograde
