Translation and Post-translation 2C part 1

Question 1

translation is the

Answer 1

assemble of amino acids into polypeptides

Question 2

tell me the structure of an amino acid

Answer 2

amine group+central carbon+hydrigen+carboxyl group and a different R group

Question 3

R group

Answer 3

This is what determines the unique character of an amino acid. What makes amino acid different

Question 4

Tell me how two amino acids are joined (3)

+ what is the bond called

Answer 4

they are joined by a covalent peptide bond between the amino and carboxyl by a dehydration reaction.

The COH (part of COOH) reacts with the amine part hydrogen to form water molecule and the conjoined two amino acid.

carboxyl carbon join with amine nitrogen

Question 5

Polypeptides

Answer 5

linear chains of amino acids linked by peptide bonds

Question 6

Non polar amino acid

Answer 6

R group usually contain CH2 or CH3

Question 7

uncharged polar amino acids

Answer 7

R groups usually contain oxygen of OH

Question 8

charged amino acids

Answer 8

R groups contain acids or bases that can ionize

Question 9

Aromatic amino acid

Answer 9

R group contain a carbon ring with alternating single and double bonds

Question 10

Methionine

Answer 10

First amino acid in polypeptide

Question 11

Proline

Answer 11

causes kink/bend in polypeptide chains

Question 12

Cysteine

Answer 12

disulphide bridge where the R group interact

Question 13

Primary amino acid sequence (3)

Answer 13

determines protein folding and 3D structure which is critical for proper function

just the linear sequence held together by peptide bond

no attention to 3D shape

Question 14

Secondary protein structure (3)

Answer 14

depends on hydrogen bonding in the peptide backbone (alpha helices and beta-sheets).

secondary structure does not involve R group atoms

hydrogen bonds, which form between the carbonyl and amino group of the peptide bond

Question 15

Tertiary protein structure (2)

Answer 15

the 3D structure of a single polypeptide and is composed of interactions between amino acid side chains

R groups interactions: ionic bonding, H bond, Vanderwall, Disulphide interaction and hydrophilic/hydrophobic

Question 16

Quaternary protein structure (2)

Answer 16

Interactions between more than one polypeptide to form a multi-subunit proteins eg: hemoglobin

hydrogen bonds, covalent bonds, or ionic bonds.

Question 17

how can protein structures be denatured (3)

Answer 17

heat
chemicals
mutations that change amino acid sequence

Question 18

Chaperones (3)

Answer 18

protect slow folding or denatured proteins by preventing their aggregation

assist large proteins in proper protein folding during or after synthesis, and after partial denaturation

assist in protein folding by binding to and stabilizing folding intermediates until the polypeptide chain is fully translated.

Question 19

aggregation (2)

associated with….

Answer 19

intrinsically-disordered or mis-folded proteins aggregate (i.e., accumulate and clump together)

associated with Alzheimer’s, Parkinson and Creutzfeldt-Jakob

Question 20

tRNAs

Answer 20

adaptors between codons (mRNA) and amino acids

2-D 3 cloverleaf and 3-D L shaped folded RNA molecule from complimentary pairing.

Question 21

Acceptor stem tRNA (2)

Answer 21

Where amino acid is attaches

contains the sequence 5’-CCA-3’ at the end of the 3’ end of tRNA

Question 22

Anticodon (3)

Answer 22

the bottom loop of the cloverleaf contains three nucleotide sequence that recognize the codon by base pairing with mRNA

Each tRNA has its corresponding amino acid attached to its end.

anticodon binding to codon is antiparallel

Question 23

aminoacyl-tRNA synthase (2)

Answer 23

adds amino acid to the acceptor stem of the correct tRNA

20 different aminoacyl-tRNA synthase for 20 different amino acids

Question 24

charging reaction (3)

Answer 24

aminoacyl-tRNA synthase binds with ATP and amino acid causing two pyrophosphates to be released and ATP turns to AMP. Amino acid+AMP complex is formed

Correct tRNA binds with the enzyme.( Amine group free) The enzyme transfer amino group to tRNA. Amp is then released.

Amino acid-tRNA is released

Question 25

What does the Amp do in tRNA charging?

Answer 25

The animoacyl tRNA synthetase used the energy supplied by ATP to charge the tRNA with the correct amino acid so that it can be used again in the process of translation.

Question 26

sense codon

Answer 26

codes for amino acid

Question 27

codons are written in the table

Answer 27

5’-3’ as they appear in the mRNA

CUU
5’-3’

Question 28

Stop codons +which codes

(5)

Answer 28

UAA
UAG
UGA

do not code for amino acids. tRNA does not bind to these codons

STOP codons cause the release of the new polypeptide chain from the ribosome

Question 29

degeneracy in genetic code

Answer 29

more than one codon can specify an amino acid

Question 30

how many codons

Sense+total

Answer 30

61 sense codons

64 total codons

Question 31

Tell me about methionine group in translation

Answer 31

first methionine that ribosome encounter as it travels 5’-3’ is start codon

Question 32

ribosome gets recruited to

Answer 32

5’ cap of mRNA and start to read

Question 33

codons are read ……

not the 5’-3’ part

Answer 33

non overlapping and no gaps. read 1 nucleotide just once and in 3s

Question 34

+4 frame

Answer 34

same +1 frame

Question 35

wobble (3)

degeneracy

used words like codon+anticodon

general

Answer 35

there are less than 61 tRNA because some tRNA can read/bind more than 1 codon

this is because the base at the 5’ end of the anticodon can form H bonds with more than one type of base located at the 3’ end of a codon.

Binding of a codon in an mRNA the cognate tRNA is much “looser” in the third position of the codon. This permits several types of non-Watson–Crick base pairing to occur at the third codon position

Question 36

flexibility occurs only at the _____ end of the anticodon

Answer 36

5’

Question 37

pairing of the other 2 nucleotides in the anticodon

Answer 37

is percise/no wobble