Genetics And Protein Synthesis

Question 0

Why is the DNA copied into RNA?

Answer 0

The DNA is too large to move out of the nucleus, so it is copied into RNA.

Question 1

What is the organelle for protein synthesis and where is it found?

Answer 1

The ribosomes are found in the cytoplasm.

Question 2

What is transcription?

Answer 2

A section of DNA is copied into RNA

Question 3

RNA is a single $$$ strand?

Answer 3

RNA is a single POLYNUCLEOTIDE strand.

Question 4

What does RNA contain?

Answer 4

The sugar ribose

Question 5

Uracil replaces which base in protein synthesis?

Answer 5

THYMINE!

Question 6

When the RNA leaves the nucleus it joins with what in the cytoplasm?

Answer 6

A RIBOSOME!

Question 7

Once the RNA has joined with a ribosome, it can be used to synthesise a ¥¥¥ in the cytoplasm?

Answer 7

Protein!

Question 8

In simple, brief terms what is translation?

Answer 8

The RNA joining with a ribosome and synthesising a protein.

Question 9

mRNA?

Answer 9

• carries the genetic code from the DNA in the nucleus to the cytoplasm,where it’s used to make a protein during translation.
• three adjacent bases are called a codon.

Question 10

tRNA?

Answer 10

• it carries the amino acids that are used to make proteins to the ribosomes
• it has an amino acid binding site at one end and a sequence of 3 bases at the other end called a codon.

Question 11

Which comes first, transcription or translation?

Answer 11

Transcription then translation

Question 12

TRANSCRIPTION: step 1

Transcription starts when RNA polymerase attaches to ¥¥¥ &&&& at the beginning of a gene

Answer 12

DNA double-helix

Question 13

TRANSCRIPTION: step 2

the

Answer 13

HYDROGEN!

Question 14

TRANSCRIPTION: step 3

What is used as a template to make an mRNA copy.

Answer 14

One of the uncoiled DNA strands

Question 15

TRANSCRIPTION: step 3

What is the antisense strand?

Answer 15

The DNA template strand

Question 16

TRANSCRIPTION: (step 4)

The RNA polymerase lines up

Answer 16

Free RNA nucleotides

Question 17

TRANSCRIPTION: (step 4)

What is complimentary base pairing?

Answer 17

It means that the mRNA strand ends up being a reverse copy of the DNA template strand (except the base T is replaced by U in RNA)

Question 18

TRANSCRIPTION: (step 5)
What molecule is formed when the RNA nucleotides have paired up with their complementary bases on the DNA strand and been joined together?

Answer 18

An mRNA molecule

Question 19

TRANSCRIPTION:(step 6)

What does RNA polymerase do once the first mRNA molecule has been formed?

Answer 19

The RNA polymerase moves along the DNA, separating the strands and assembling the mRNA strand.

Question 20

TRANSCRIPTION (step 7)

What happens to the uncoiled strands of DNA now the RNA polymerase has passed by?

Answer 20

The hydrogen bonds between the uncoiled strands of DNA reform and the strands coil back into a double helix.

Question 21

TRANSCRIPTION (step 8)

What stops RNA polymerase making mRNA

Answer 21

A stop codon, and then the RNA polymerase detaches from the DNA.

Question 22

TRANSCRIPTION (step 9)

Through what does the mRNA move out of the nucleus

Answer 22

Nuclear pore

Question 23

TRANSCRIPTION (step 9)

Once the mRNA has left the nucleus, what does it do?

Answer 23

The mRNA attaches to a ribosome in the cytoplasm, where translation takes place.

Question 24

What are introns?

Answer 24

Sections of DNA that don't code for amino acids.

Question 25

What are exons?

Answer 25

Bits of DNA that do code for amino acids

Question 26

During transcription, the introns and exons are both copied onto what?

Answer 26

mRNA

Question 27

After transcription where both the introns and exons are copied into mRNA, what happens to the introns and what is the process called?

Answer 27

The introns are removed by a process called 'splicing' where introns are removed and exons are joined forming mRNA strands.

Question 28

Where does splicing take place?

Answer 28

The nucleus

Question 29

The exons can be joined together in different orders to form different mRNA strands. Why?

Answer 29

This means that more than one amino acid sequence and so more than one protein can be produced from one gene.

Question 30

TRANSLATION (step 1) | The mRNA attaches itself to a ribosome and which molecules carry amino acids to the ribosome?

Answer 30

tRNA molecules.

Question 31

TRANSLATION (step 2) | How does the tRNA molecule attach itself to the mRNA molecule?

Answer 31

Complementary base pairing.

Question 32

TRANSCRIPTION (step 3) | What happens after the first tRNA molecule attaches itself to the mRNA?

Answer 32

A second tRNA molecule attaches itself to the next codon on the mRNA in the same way.

Question 33

TRANSLATION (step 4) | What kind of bond joins the two amino acids attached to the tRNA molecules?

Answer 33

a peptide bond

Question 34

TRANSLATION (step 4) The first tRNA molecule moves away once the two amino acids have been joined by peptide bonds, and the first tRNA's what is left behind?

Answer 34

Amino acid!

Question 35

TRANSLATION (step 5) | A third tRNA molecule binds to the next codon on the mRNA. It's

Answer 35

Amino acid!

Question 36

TRANSLATION (step 6) The process of tRNA molecules moving away from the mRNA once the amino acids have joined continues, what does it produce and when does it stop?

Answer 36

A polypeptide chain, and it stops when there's a stop codon on the mRNA molecule.

Question 37

TRANSLATION (step 7) | What is the final step?

Answer 37

The polypeptide chain (protein) moves away from the ribosome and translation is complete.