Lecture 8 Flashcards

0
Q

What is a set of rules that covert the nucleotide sequence of a gene inot the amino acid sequence of protein

A

genetic code

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1
Q

A protein is synthesized in the

A

amino to carboxyl direction by the sequential addition of amino acids to the carboxyl end of the growing peptide chain

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2
Q

What is teh genetic code intermediary?

A

mNA

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3
Q

How is the sequence of nucleotides in the mRNA molecule read?

A

consecutively in groups of three

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4
Q

What is each group of 3 consecutive nucleotides in RNA called?

A

a codon

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5
Q

What does a codon specify?

A

Either one amino acid or a stop to the translation process

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6
Q

How many total codons?

A

61 triplet codons code for the 20 known amino acids, thus the cod is degenerate

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7
Q

What does degenerate mean?

A

More than one codon per amino acid

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8
Q

How does an amino acid recognize a codon?

A

tRNA

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9
Q

How can the codons in mRNA be translated into a protein?

A

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10
Q

What is the adaptor hypothesis?

A

It postulates that the genetic code is read by molecules that can recognize a codon and carry the corresponding amino acide

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11
Q

What does transfer RNA or tRNA do?

A

serves as an adaptor that binds to a specific codon and brings iwth it an amino acid for incorporation into the polypeptide chain

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12
Q

What is the secondary structure of tRNA?

A

cloverleaf… tRNA fold up into a defined 3D strucutre an contains 4 short double helical segments

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13
Q

What are two regions of of tRNA?

A

two regions of unpaired nucleotides are curitcial to the function

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14
Q

What is the anticodon loop of tRna?

A

a set of 3 consecutive nuclellotides that pair with a compelnetary….

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15
Q

….

A

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16
Q

Are there more than one tRNA for most amino acids?

A

yes

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17
Q

Some tRNAs require accurate base pairing only at?

A

the first two positions of the codon and can tolerate a mismatch?

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18
Q

What is it called when it can tolerate a mismatch?

A

wobble hypthesis

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19
Q

What does the wobble base pairing explain/

A

Why so many of the alternative….

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20
Q

Amino acid reacts with? for the activation of adenylated amino acid?

A

ATP looses 2 phosphates…

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21
Q

adenylated amino acid is?

A

amino acid-AMP

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22
Q

What is the recognition and attachment of the correct amino acid to the corresponding tRNA catalyzed by?

A

aminoacyl-tRNA synthestases

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23
Q

What does aminoacyl-tRNA synthatase do?

A

24
Q

….

A

….

25
Q

….

A

….

26
Q

at tRNA level there is a bonding site for the?

A

anti codon

27
Q

Editing (hydrolytic) site cleaves …. speicies that are …. than the correct one

A

activated, smaller

28
Q

What raises the overal accuracy of tRNA chargin to approximately on mistake in 40,000 coupling

A

hydrolytic editing…. this is on the snythatase

29
Q

What is the genetic code translated by?

A

two adaptors

30
Q

What are the two adaptors?

A

tRNA and the tRNA synthetase

31
Q

What contains highly discriminating amino acid

A

….

32
Q

….

A

….

33
Q

….

A

….

34
Q

A

35
Q

Prokaryotic ribosome

A

70s… small subunit

36
Q

eukaryotic ribosome

A

80s and small subunit

37
Q

What is a ribosome?

A

A complex catalytic machine, consiting of two subuits

38
Q

What does each ribosome subunit consist of?

A

Different ribosomal proteins and several ribosomeal RNAs (rRNAs)

39
Q

What determin the overall shape of the ribosome?

A

rRNAs

-its ability to postition tRNAs on the mRNA, adn it scatalytic activity in forming peptide bonds

40
Q

small subunit?

A

provides…

41
Q

large subunit

A

42
Q

Protein synthesis is performed on?

A

the ribosome

- it ensures accuracy and maintains correct reading frame

43
Q

What are separate when not snythesizing proteins?

A

the 2 ribosomes su

44
Q

How are the ribosomes subunits joined/

A

join together at the 5’ end of mRNA and initaed protien snythesis

45
Q

What direction is teh ribosoem pulled through?

A

5-3 direction

46
Q

A

47
Q

A

48
Q

Where does the ribosome making occur?

A

cytosol

49
Q

What is a polyribosome?

A

50
Q

What contains 4 binding sites for RNA

A

ribosomes

51
Q

what are the three tRNA sites?

A

A(aminoacyl)
P(peptidyl)
E(exit)

52
Q

What is the 4ths bieing site for?

A

mRNA

53
Q

The A, P and E site

A

….

54
Q

….

A

….

55
Q

….

A

56
Q

What is teh fundamental reaction of protein snythesis?

A

The formation of peptide bond btw amino acids

57
Q

Where does the reaction of protein snythsis occur?

A

58
Q

A