UMD BSCI 330 exam 2 Questions and Answers with complete solution
6 views 0 purchase
Course
UMD BSCI 330
Institution
UMD BSCI 330
How does translation terminate? - ️️-stop codon (UAA, UAG,UGA)
-instead of tRNA, release factor binds to ribosome, causing hydrolysis of the peptidyl
tRNA, releasing the completed protein
-ribosome dissociates into its subunits, releasing mRNA, release factor, and tRNA
mRNA and protein synt...
UMD BSCI 330 exam 2
How does translation terminate? - ✔️✔️-stop codon (UAA, UAG,UGA)
-instead of tRNA, release factor binds to ribosome, causing hydrolysis of the peptidyl
tRNA, releasing the completed protein
-ribosome dissociates into its subunits, releasing mRNA, release factor, and tRNA
mRNA and protein synthesis are very energetically - ✔️✔️adding each subunit requires
the conversion of an NTP to an NMP, equivalent to hydrolyzing 2 ATPS to ADP
-elongation step consume multiple ATP/GTP
-splicing and proofreading use up even more ATP/GTP molecules
codon - ✔️✔️set of 3 nucleotides
-most amino acids have multiple corresponding codons
tRNA - ✔️✔️matches amino acids with codons
-amino acid is covalently attached to the 3' end of the tRNA
-contains loop with an anticodon that is complementary to the appropriate amino acids
codon
Amino acid activation - ✔️✔️-first activated by conjugation to AMP (energetically
expensive) then the aa is transferred to tRNA, resulting in a high energy bond
Proofreads translation - ✔️✔️Synthetase, each aa has a distinct synthetase which
proofreads for accuracy
ribsozyme - ✔️✔️rRNAs make up the structural and catalytic core
Ribosome function - ✔️✔️reads mRNA from 5 to 3, reading 3 bases at a time
-ribosome chooses one of three potential rwading frames
How does translation begin? - ✔️✔️codon AUG (Met)- which uses a special initiator
tRNA that differs from the Met tRNA used for the rest of translation
Elongation Factors - ✔️✔️-prokaryotes- EF-tu/EF-g
euk- EF1/2
- use GTPase activity to allow proofreading and to speed up ribosome translation
Protein Translation - ✔️✔️20 different amino acids
-triple nucleotide code= 64 different combinations
, polyribosome - ✔️✔️-a single mRNA may thus have several ribosomes translating
simultaneously
Antibiotics and protein synthesis - ✔️✔️-protein synthesis inhibitors
-most effect only prokaryotes, but sometimes can also affect ribosomes in mitochondria
and chloroplasts
The 3D structure of a protein determines its _________ - ✔️✔️function
describe the structure of primary proteins - ✔️✔️-linear sequence of amino acid residue
-determined by mRNA code
the structure of primary amino acids is dependent on? - ✔️✔️-covalent binds b/t amino
acids in linear sequence
-determines secondary tertiary and quaternary structures in combination with proteins
environment
describe structure of secondary proteins - ✔️✔️-folding & twisting of peptide backbone
-NO amino acid side chain interactions
_R groups stick out from backbone
the structure of secondary protein is dependent on? - ✔️✔️weak H-bonds b/t C=O
carbonyl & N-H amine groups in backbone
- NOT SIDE CHAINS
What are two well known structures of secondary proteins? - ✔️✔️-alpha helices
-beta sheets
describe the structure of alpha helix - ✔️✔️-rigid cylindrical structure
-coils clockwise down the length of the chain
the structure of alpha helix is dependent on? - ✔️✔️H-bonding between C=O & N-H
that are 4 amino acids apart ON BACKBONE
4 amino acids = ___ helix turns - ✔️✔️ONE
describe the structure of beta sheet's - ✔️✔️-flat, sheet-like structure
-perpendicular interactions
the structure of beta sheet's is dependent on? - ✔️✔️H-bonding is between C=O & N-H
on ADJACENT polypeptide chains
in beta sheet's, adjacent polypeptide chains can be
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller PatrickKaylian. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $8.39. You're not tied to anything after your purchase.
