DNA Test Part Two: Protein Synthesis

Question 1

Ribosomes

Answer 1

use the sequence of codons in the mRNA to assemble amino acids into polypeptide chains

Question 2

Transcription

Answer 2

Process by which genetic information encoded in DNA is copied into mRNA with the help of RNA polymerase
Occurs in the nucleus
DNA-mRNA
It forms three types of RNAs rRNA tRNA and mRNA
Transcription requires RNA polymerases and some transcription factors

Question 3

Translation

Answer 3

Process by which information encoded in mRNA is used to assemble a protein at a ribosome creating a polypeptide chain
Occurs on a ribosome
mRNA - Protein
All the three types of RNAs take part in translation.
Translation requires initiation, elongation and translocase factors

Question 4

Translation steps

Answer 4

Ribosome positions the AUG start codon and it’s anticodon
Each tRNA has anticodon to match up with a codon on the mRNA strand
The ribosome joins two amino acids (meth and phen) and breaks the bond between meth and tRNA tRNA leaves the ribosome allowing the ribosome to bind another tRNA
the ribosome goes along the mRNA strand binding tRNA and amino acids
This continues until the ribosome reaches a stop codon
once the polypeptide chain is complete it and the mRNA are released from the ribosome

Question 5

Transcription steps

Answer 5

To begin transcribing a gene, RNA polymerase binds to the DNA of the gene at a region called the promoter.
Basically, the promoter tells the polymerase where to “sit down” on the DNA and begin transcribing
During elongation, RNA polymerase “walks” along one strand of DNA, known as the template strand, in the 3’ to 5’ direction. For each nucleotide in the template, RNA polymerase adds a matching (complementary) RNA nucleotide to the 3’ end of the RNA strand.
RNA polymerase will keep transcribing until it gets signals to stop.
The process of ending transcription is called termination, and it happens once the polymerase transcribes a sequence of DNA known as a terminator.
The peptide chain leaves the ribosome

Question 6

Difference in bases

Answer 6

Coding strand T
RNA U
Template strand A

Question 7

Promoter

Answer 7

A promoter is a region of DNA that initiates transcription of a particular gene. Promoters are located near the transcription start sites of genes towards the 5’ region of the sense strand

Question 8

mRNA

Answer 8

mRNA Transcribes the genetic code from DNA into a form that can be read and used to make proteins. mRNA carries genetic information from the nucleus to the cytoplasm of a cell

Question 9

tRNA

Answer 9

tRNA is located in the cellular cytoplasm and brings or transfers amino acids to the ribosome that correspond to each three-nucleotide codon of rRNA. The amino acids then can be joined together and processed to make polypeptides and proteins

Question 10

rRNA

Answer 10

Ribosomal RNA rRNA is located in the cytoplasm of a cell, where ribosomes are found. rRNA directs the translation of mRNA into proteins

Question 11

Enzymes involved in protein synthesis

Answer 11

Helicase - unzips DNA
DNA polymerase - DNA Polymerase synthesizes a DNA strand and used in DNA replication
RNA polymerase - used during transcription to synthesize the mRNA strand no proofreading systems
Telomerase - less likely that DNA will be lost from telomeres during replication

Question 12

Protein Sythesis

Answer 12

Protein synthesis is one of the most fundamental biological processes by which individual cells build their specific proteins. Within the process are involved both DNA (deoxyribonucleic acid) and different in their function ribonucleic acids (RNA). The process is initiated in the cell’s nucleus, where specific enzymes unwind the needed section of DNA, which makes the DNA in this region accessible and a RNA copy can be made

Question 13

Helicase

Answer 13

separate double-stranded DNA into single strands allowing each strand to be copied

Question 14

DNA polymerase

Answer 14

DNA Polymerase synthesizes a DNA strand and used in DNA replication

Question 15

RNA polymerase

Answer 15

used during transcription to synthesize the mRNA strand no proofreading systems

Question 16

Telomerase

Answer 16

less likely that DNA will be lost from telomeres during replication

Question 17

Protein Synthesis steps

Answer 17

RNA polymerase binds to the promoter, a base sequence signalling the start of the gene

DNA is synthesized in the 5’ to 3’ direction, creating only one strand. T is replaced by U

This pre-mRNA is spliced to remove the introns then travels to the ribosome

rRNA ribosome binds to mRNA

tRNA begins translating, matching the mRNA codons to its anticodons. Each anticodon is attached to an amino acid, which is then added to the polypeptide chain.

Once tRNA reaches the top codon, the process is finished and the chain detaches