Proteins and their synthesis

Question 1

What is translation?

Answer 1

The generation of specific proteins from their mRNA templates

Question 2

What 2 things does translation involve?

Answer 2

Ribosomal proteins and Functional RNAs

Question 3

What are the two functional RNAs

Answer 3

tRNAs
rRNAs

Question 4

What is the the relationship between transcription and translation in Eukaryotes?

Answer 4

It occurs in separate compartments in eukaryotes

Question 5

What is the relationship between transcription and translation in prokaryotes?

Answer 5

It occurs in the same compartment in prokaryotes

Question 6

How many amino acids are there in genetic code?

Answer 6

20

Question 7

What is released each time a peptide bond forms?

Answer 7

Water molecule

Question 8

What are the ends of a polypeptide chain called?

Answer 8

N-terminal and C-terminal

Question 9

What are the 3 parts of a ribosome?

Answer 9

Large subunit
Small subunit
decoding center

Question 10

What are the 4 levels of protein structure?

Answer 10

Primary
Secondary
Tertiary
Quaternary

Question 11

Secondary structure explanation?
What are the two conformations?

Answer 11

Local structure
Helices
Beta pleated sheet

Question 12

Tertiary structure explanation?

Answer 12

Composite of all secondary structures

Question 13

Protein structure is relatred to its function.
Globular-
Linear-
Disordered

Answer 13

Globular - antibodies
Linear - skin
Disordered -

Question 14

Protein structure is relatred to its function.
Globular-
Linear-
Disordered

Answer 14

Globular - antibodies
Linear - skin
Disordered -

Question 15

How are amino acids specified?

Answer 15

By nonoverlapping codons containing 3 adjacent nucleotides

Question 16

What did the experiments of Crick, Brenner and others indicate?

Answer 16

Using the T4 phage, they indicated that the genetic code involved triplets

Question 17

In the 1960s, Nirenberg, Matthaei, and Khorana

Answer 17

Used synthetic RNAs to crack the genetic code

Question 18

What is degeneracy?

Answer 18

Multiple sets of codons can code for the same thing
Some mutations wont change what result the codon codes for

Question 19

What can single nucleotide mutations cause?

Answer 19

They can introduce premature stop codons which break the gene

Question 20

What do tRNAs do?

Answer 20

They bring amino acids to the ribosome so it can be added to a polypeptide chain

Question 21

What 2 things do tRNA sceondary structures have?

Answer 21

Anticodons and Amino Acid attachment sites

Question 22

What does the tRNA anticodon region do?

Answer 22

Binds with a codon for addition to a polypeptide chain

Question 23

What do aminoacyl-tRNA synthetases do?

Answer 23

Covalently attach appropriate tRNAs and amino acids
tRNAs and AAs dock inside and AAs are bound

Question 24

What makes it possible for tRNAs to recognize multiple codons

Answer 24

Wobble effect

Question 25

What is special about Inosine?

Answer 25

Inosine can sometimes replace A and it can pair with A,C, or U

Question 26

Are prokaryotic or eukaryotic ribosomal subunits larger?

Answer 26

Eukaryotic

Question 27

What feature of bacterial (prokaryotes) mRNAs helps position the ribosome during translation inition?

Answer 27

Shine-Dalgarno sequence

Question 28

What are the three key sites that ribosomes have to facilitate interactions with molecules necessary for translation?

Answer 28

Acceptor Polypeptide Exit

Question 29

What role does the start codon play in initiating translation?

Answer 29

It marks the site at which translation into protein sequence begins and facilitates position of ribosome docking

Question 30

What do the stop codons trigger?

Answer 30

Stop codons recruit release factors which trigger termination of translation and trigger disassembly of ribosome

Question 31

What are the 3 stages/phases of translation?

Answer 31

Initiation Elongation Termination

Question 32

What proteins are involved in elongation?

Answer 32

Elongation factors, they allow the ribosome to shift during translation extending the polypeptide chain

Question 33

If prokaryotes have the Shine-Dalgarno sequence, what is the eukaryote version?

Answer 33

5' cap

Question 34

How does the ribosome dock in eukaryotes

Answer 34

Docking in eukaryotes is facilitated relative to the start codon and 5' cap

Question 35

What allows the large ribosomal subunit to bind to the small unit in prokaryotes?

Answer 35

F-met

Question 36

What are nonsense supressors?

Answer 36

Secondary mutations that enable translation to proceed through a premature stop

Question 37

What are post-translational modifications?

Answer 37

Additional levels of modifications to the protein that influence how they function

Question 38

What are 5 examples of PTMs?

Answer 38

1. Addition of chemical groups 2. Amino acid modifications 3. Cleavage 4. Addition of complex molecules 5. Addition of polypeptides