Bio 2b03 Exam Review 2026
Exam Questions and Correct
Answers | New Update
is the RER dynamic or stationary? - ANSWER ✔✔dynamic
what is the function of the RER? - ANSWER ✔✔co-translational
transport, protein modification, formation of vesicles that will transport
proteins from ER to Golgi
what is the function of the SER? - ANSWER ✔✔fatty acid and
phospholipid synthesis, carbohydrate metabolism, regulate Ca2+ conc in
the cytosol
,what are the post translational modifications in the ER? - ANSWER
✔✔- glycosylation
- protein folding
- disulphide bond formation
- proteolytic cleavage
do modifications to proteins embedded in the ER membrane occur in the
luminal portion or the transmembrane domain or the cytosolic portion? -
ANSWER ✔✔luminal
this protein modification is important for proteins that mediate cell
interactions with the extracellular matrix and for receptor-ligand
recognition - ANSWER ✔✔glycosylation
this protein modification is common on proteins that are secreted from
the cell and proteins embedded in the cell membrane - ANSWER
✔✔glycosylation
what is the most common form of glycosylation? - ANSWER ✔✔N-
linked
N-linked glycosylation adds a polysaccharide to which group of which
amino acid? - ANSWER ✔✔NH2 group of the R-group of asparagine
,these proteins recognize modified proteins and assist in protein folding
in a similar way as chaperones - ANSWER ✔✔lectins
what are the two types of lectins? - ANSWER ✔✔calnexin and
calreticulin
where is calnexin found? - ANSWER ✔✔ER membrane
what is BiP? mention 3 functions - ANSWER ✔✔- 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? - ANSWER ✔✔Hsp40 and NEF
is cytoplasm a reducing or an oxidizing environment? - ANSWER
✔✔reducing
is ER a reducing or an oxidizing environment? - ANSWER
✔✔oxidizing
3
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2026. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED
, does disulphide bond formation occur in reducing or oxidizing
environment? - ANSWER ✔✔oxidizing
this protein is one of many proteins secreted into the intestine where it
aids in the digestion of RNA by cleaving it into small pieces -
ANSWER ✔✔RNAse A
what is the protein that resides in the ER that promotes oxidation? -
ANSWER ✔✔protein disulphide isomerase (PDI)
does proteolytic cleavage in the ER happen in the lumen or the cytosol?
- ANSWER ✔✔lumen
what is the N-terminal signal sequence of type I integral proteins cleaved
by? - ANSWER ✔✔signal peptidase
what are the two responses of the unfolded protein response (UPR)? -
ANSWER ✔✔1. restore normal cell function by slowing down new
protein translation or removing unfolded proteins from the ER for
degradation through ubiquitylation
2. increase production of chaperones
what are the proteins essential to UPR? - ANSWER ✔✔BiP and Ire1
Exam Questions and Correct
Answers | New Update
is the RER dynamic or stationary? - ANSWER ✔✔dynamic
what is the function of the RER? - ANSWER ✔✔co-translational
transport, protein modification, formation of vesicles that will transport
proteins from ER to Golgi
what is the function of the SER? - ANSWER ✔✔fatty acid and
phospholipid synthesis, carbohydrate metabolism, regulate Ca2+ conc in
the cytosol
,what are the post translational modifications in the ER? - ANSWER
✔✔- glycosylation
- protein folding
- disulphide bond formation
- proteolytic cleavage
do modifications to proteins embedded in the ER membrane occur in the
luminal portion or the transmembrane domain or the cytosolic portion? -
ANSWER ✔✔luminal
this protein modification is important for proteins that mediate cell
interactions with the extracellular matrix and for receptor-ligand
recognition - ANSWER ✔✔glycosylation
this protein modification is common on proteins that are secreted from
the cell and proteins embedded in the cell membrane - ANSWER
✔✔glycosylation
what is the most common form of glycosylation? - ANSWER ✔✔N-
linked
N-linked glycosylation adds a polysaccharide to which group of which
amino acid? - ANSWER ✔✔NH2 group of the R-group of asparagine
,these proteins recognize modified proteins and assist in protein folding
in a similar way as chaperones - ANSWER ✔✔lectins
what are the two types of lectins? - ANSWER ✔✔calnexin and
calreticulin
where is calnexin found? - ANSWER ✔✔ER membrane
what is BiP? mention 3 functions - ANSWER ✔✔- 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? - ANSWER ✔✔Hsp40 and NEF
is cytoplasm a reducing or an oxidizing environment? - ANSWER
✔✔reducing
is ER a reducing or an oxidizing environment? - ANSWER
✔✔oxidizing
3
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2026. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED
, does disulphide bond formation occur in reducing or oxidizing
environment? - ANSWER ✔✔oxidizing
this protein is one of many proteins secreted into the intestine where it
aids in the digestion of RNA by cleaving it into small pieces -
ANSWER ✔✔RNAse A
what is the protein that resides in the ER that promotes oxidation? -
ANSWER ✔✔protein disulphide isomerase (PDI)
does proteolytic cleavage in the ER happen in the lumen or the cytosol?
- ANSWER ✔✔lumen
what is the N-terminal signal sequence of type I integral proteins cleaved
by? - ANSWER ✔✔signal peptidase
what are the two responses of the unfolded protein response (UPR)? -
ANSWER ✔✔1. restore normal cell function by slowing down new
protein translation or removing unfolded proteins from the ER for
degradation through ubiquitylation
2. increase production of chaperones
what are the proteins essential to UPR? - ANSWER ✔✔BiP and Ire1
