Translation/ Protein Synthesis

Question 1

Describe the structure of tRNA

Answer 1

transfer RNA act as adapters that select specific AA and hold them into place on a ribosome for their incorporation into protein. This results in a clover like shape and then is compacted again into an L shape.

Question 2

How does RNA polymerase start transcription?

Answer 2

when it collides with a DNA and slides down the double helix until it encounters a gene region known as a promoter.

Question 3

What is the gene region known as a promoter?

Answer 3

a region the contains a specific sequence of nucleotides that lie upstream of the starting point for RNA synthesis.

Question 4

What is mRNA?

Answer 4

messenge RNA that codes for proteins

Question 5

What is rRNA?

Answer 5

ribosomal RNA form the core of the ribosomal structure and catalyze protein structure.

Question 6

What is miRNA?

Answer 6

microRNA regulates gene expression

Question 7

What is non-coding RNA used for?

Answer 7

-used in RNA splicing -telomere maintenance

Question 8

tRna match _____ to _____ in mRNA.

Answer 8

Amino Acids ; Codons

Question 9

What is aminoacyl-tRNA? synthetase?

Answer 9

covalently couples each amino acid to its appropriate set of tRNA molecules. This is known as charging!

Question 10

What is charging in respects to tRNA and amino acids?

Answer 10

charging occurs when correct amino acids are covalently bonded to their tRNA.

Question 11

What is genetic code?

Answer 11

The rules by which the nucleotide sequence of a gene, through an intermediary mRNA molecule, is translated into the amino acid sequence of a protein.

Question 12

Explain what a codon is?

Answer 12

Each group of three consecutive nucleotides in RNA , and each codon specifies one amino acid ex. 5’ AGUGCGAGAA(CCA)3’ –Amino (codon)

Question 13

Explain what an anti-codon is?

Answer 13

a set of three consecutive nucleotides that bind, through base-pairing, to the complementary codon in an mRNA molecule ex. 5’GCGAGUUGGGACU(GAA)ATCGACCA3’-Amino (anticodon)

Question 14

What two regions of unpaired nucleotides situated at either end of the L-shaped tRNA molecule are crucial to the function of tRNAs in protein synthesis?

Answer 14

codons and anticodons

Question 15

Comparison of Prokaryotic and Eukaryotic replication:

Answer 15

Question 16

What transcribes DNA to RNA?

Answer 16

DNA is transcribed into RNA
by the enzyme RNA polymerase.

Question 17

How is DNA transcribed by RNA Polymerase?

Answer 17

RNA polymerase moves stepwise
along the DNA, unwinding the DNA helix in
front of it. As it progresses, the polymerase
adds ribonucleotides one by one to the
RNA chain, using an exposed DNA strand as
a template. The resulting RNA transcript is
thus single-stranded and complementary to
this template strand. As the polymerase moves along the DNA template, it displaces the newly formed RNA, allowing the two strands of DNA behind the polymerase to rewind. A short region of hybrid DNA/RNA helix therefore forms only transiently, causing a “window” of DNA/RNA helix to move along the DNA with the polymerase

Question 18

DNA is transcribed to RNA how:

(with diagram)

Answer 18

Question 19

An Exion is:

Answer 19

are usually shorter than the introns, and they often represent only a small fraction of the total length of the gene

Question 20

An Intron is:

Answer 20

a noncoding segment in a length of DNA that interrupts a gene-coding sequence or nontranslated sequence, the corresponding segment being removed from the RNA copy before transcription.

Question 21

What is a 3’ Untranslated region?

Answer 21

A region of the DNA which IS transcribed into mRNA and becomes the 3’ end or the message, but which does not contain protein coding sequence. Everything between the stop codon and the polyA tail is considered to be 3’ untranslated

Question 22

What is a 5’ Untranslated region?

Answer 22

A region of a gene which IS transcribed into mRNA, becoming the 5’ end of the message, but which does not contain protein coding sequence. The 5’-untranslated region is the portion of the DNA starting from the cap site and extending to the base just before the ATG translation initiation codon

Question 23

What is a terminator?

Answer 23

is where the polymerase halts and releases both the DNA template and the newly made RNA transcript. This terminator sequence is contained within the gene and is transcribed into the 3’ end of the newly made RNA.