MODULE 3 Translation

Question 1

_____ the process by which the information in the DNA code is translated into proteins.

Answer 1

Protein synthesis

Question 2

7 stages of Protein synthesis

1) DNA is transcribed into ____. The way it is transcribed may be affected in multiple ways

2) The ____ leaves the ___ through the ___ and moves to the surface of a ___

3) ___ binds to the surface of a ____

4) Molecules of ____ carry individual ___ and line it up against a complementary codon on the mRNA.

Answer 2

1) DNA is transcribed into MESSENGER RNA. The way it is transcribed may be affected in multiple ways.

2) The mRNA leaves the NUCLEUS through the NUCLEAR PORES and moves to the surface of a RIBOSOME

3) mRNA binds to the surface of a RIBOSOME

4) Molecules of TRANSFER RNA carry individual AMINO ACIDS and line it up against a complementary codon on the mRNA.

Question 3

7 stages of Protein synthesis

5) _____ link the amino acids together, formiing ___. ____ breaks away and returns to the ___ to pick up another amino acid.

6) The ____ moves along the molecule of mRNA until the end is reached. The completed ___ detaches and moves into ___ for further modification or into the ___ to undergo proper ____. Either makes it a functional protein.

7) The ____ may be read repeatedbly before being released from the surface of the Ribosome.

Answer 3

5) RIBOSOMAL ENZYMES link the amino acids together, forming PEPTIDE BONDS. tRNA breaks away and returns to the CYTOPLASM to pick up more amino acid.

6) The RIBOSOME moves along the molecule of mRNA until the end is reached. The completed POLYPEPTIDE detaches and moves into GOLGI APPARATUS for further modification or into the CYTOPLASM to undergo proper FOLDING. Either makes it a functional protein.

7) The mRNA may be read repeatedly before being released from the surface of the ribosome.

Question 4

Each ____ are synthesized from the ___ to the ___.

Each amino acid is specified by three bases (___) in the mRNA which is a nearly universal genetic code.

Answer 4

Each Polypeptide chain are synthesized from the AMINO to the CARBOXY TERMINUS

Each amino acid is specified by three bases (CODON) in the mRNA which is a nearly universal genetic code.

Question 5

BASIC COMPONENTS:

_____ transmits information present in DNA

____ acts as a bilingual translator molecule

____ the workbenches for protein synthesis

____ serve to mediate the attachment of specific amino acids to specific tRNA moolecules

_____ basic

Answer 5

mRNA

tRNA

Ribosomes and rRNA

tRNA synthetases

amino acid

Question 6

Eukaryotic mRNAs encode ____ protein, whereas bacterial mRNAs encode ___ protein.

Eukaryotic mRNAs are capped by ____ with a ____ which allows it to be stable. It is also a binding site for proteins and protection against attacks by nucleases.

Eukaryotic mRNAs have a ____ which has 50 to 3000 adenine residues on it, it helps from degradation in the cytoplasm. It promotes export.

Answer 6

Eukaryotic : 1
Prokaryotic: more than 1

7-methylguanosine residue
5’-triphosphate-5’

poly(A) tail

Question 7

____ transcribes information present in DNA

Answer 7

Messenger RNA (mRNA)

Question 8

mRNA:

In Eukaryotes, the mRNA encodes for ____ polypeptide ____

In prokaryotes, the mRNA encodes for ____ polypeptide ____

Answer 8

Eukaryotes:
One polypeptide
Monocistronic

Prokaryotes:
Multiple polypeptide
Polycistronic

Question 9

mRNA:

In eukaryotes, the 5’ end is ___

In prokaryotes, 5’ end is ___

Answer 9

Eukaryotes:
capped, 7 methylguanosine

Prokaryotes:
not capped

Question 10

mRNA:

In eukaryotes, the 5’-nontranslated region separates the cap from the ____

In prokaryotes, ____ are preceded by the specific nucleotide sequence called the ____

Answer 10

Eukaryotes:
translational initiation signal

Prokaryotes:
Initiation codons

Shine-Delgarno sequence

Question 11

Name of non-coding sequences in prokaryotes and eukaryotes

Answer 11

5’UTR

3’ UTR

Question 12

____ Determines how the nucleotide sequence specifies the amimo acid sequence of a protein

The locations of the nucleotide in the first, second, and third positions define the amino acid specified by the code

Answer 12

The genetic Code

Question 13

Characteristics of the Genetic code:

How many letters are there in the genetic code?

Each amino acid is encoded by three consecutive nucleotides, called ____

Answer 13

4 (A C G U/T)

Codons

Question 14

Characteristics of the Genetic code:

It is ____ which means that out of 64 codons, only 61 codons code for the 20 amino acids in proteins (3 codons are ____)

Answer 14

Degenerate

Termination codons

Question 15

Characteristics of the Genetic code:

The two amino acids which only have a single codon to code for them. (The others have two or more)?

Answer 15

Methionine
Tryptophan

Question 16

The code is generally ____ which means that each nucleotide belongs to a single reading frame.

The reading frame is started by an ____ or Start, which is AUG

The three ____ can signal the end of a protein. They are UAA, UAG, or UGA

Answer 16

Nonoverlapping

Initiation codon

Termination codon

Question 17

Where the genetic code is not universal (3)

Answer 17

Prokaryotes
Mitochondria
Chloroplasts

Question 18

____ are adapters that deliver amino acids to the translation machinery by matching ___ with their corresponding amino acids as they are incorporated into a growing ____

Answer 18

TRANSFER RNAs are adapters that deliver amino acids to the translation machinery by matching mRNA CODONS with their corresponding amino acids as they are incorporated into a growing POLYPEPTIDE

Question 19

Specialized tRNAs that carry ____ or ____ in bacteria initiate protein synthesis.

Answer 19

Methionine

Formylmethionine

Question 20

Transfer RNAs consist of ___ nucleotides that basepair to form ____ and ___. These elements of secondary structure fold to form an L-shaped molecule.

A “decoding” triplet (the ____) is at one end of the L. And the amino acid acceptor site is at the other end of the L

Answer 20

~76 nucleotides

four stems
three intervening loops

(the anticodon)

Question 21

Enzymes called ____ catalyze a two-step reaction that couples the amino acid to its appropriate tRNA

Answer 21

Aminoacyl-tRNA (aa-tRNA) synthetases

Question 22

_____ Particles composed of rRNA and proteins that are the sites of protein synthesis.

It translates the 4-letter language in mRNA into the 20-letter language in protein by a ribosome

Giant macromolecular machines that bring together an mRNA and aa-tRNAs

Answer 22

The Ribosome

Question 23

The sizes of the subunits of ribosomes are traditionally given in ____.

It should be noted that mammalian ribosomes have larger RNAs and more proteins than prokaryotic and Mitochondrial ribosomes

Answer 23

Svedburg

Question 24

You can find ribosomes in the ___ or bound to the ___

However, they are formed in the ___

Its component, rRNA the most abundant RNA in the cell is formed in the _____

Answer 24

Cytoplasm
Rough Endoplasmic reticulum

Nucleolus

Nucleus