2.7 DNA Replication, Transcription, Translation

Question 0

DNA polymerase

Answer 0

Catalyses the formation of covalent bonds between two ajoining nucleotides

Question 1

DNA replication

Answer 1

Separation of double helix into 2 single strands by breaking hydrogen bonds with the help of an enzyme, Helicase. It is semi-conservative

Question 2

Protein synthesis

Answer 2

Determines the control the DNA has over the cell, some proteins are enzymes, if some or not produced it has a dramatic effect on the cell. Proteins synthesised in the cytoplasm, mRNA carries msg

Question 3

Genes

Answer 3

Section of DNA that codes for polypeptides. Any one gene is a specific sequence of nitrogenous bases found in a specific location of DNA

Question 4

Nucleoplasm

Answer 4

An area containing free nucleotides used for DNA and RNA replication

Question 5

Transcription

Answer 5

Same as replication except only area of DNA of one gene is unzipped and then sent to cytoplasm for protein synthesis.

Question 6

RNA polymerase

Answer 6

Used as a catalyst for transcription, like helicase

Question 7

Difference between DnA replication and transcription

Answer 7

• only 1 of 2 strands of DNA is copied
• mRNA always single stranded, shorter
• Uracil in RNA, thymine in DNA

Question 8

Polypeptides

Answer 8

Composed of amino acids covalently bonded together in a specific sequence

Question 9

mRNA

Answer 9

Contains a msg written in it that determines the order of the amino acids

Question 10

Triplet

Answer 10

A set of 3 bases contains information enough to code for one of 20 amino acids, when found in mRNA called a “codon triplet”

Question 11

rRNA

Answer 11

Ribosomal RNA, each ribosome is composed of rRNA and ribosomal protein

Question 12

tRNA

Answer 12

Transfer RNA, each type of tRNA transfers 1 of 20 amino acids to the ribosome for polypeptide formation, only carry one amino acid

Question 13

Translation step 1

Answer 13

mRNA is posted out of nucleus attaches to rinosome with first 2 codon triplets. Ribosomes use complementary base pairing to red codons on the mRNA. tRNA anticodon complementary to first codon triplet of mRNA. First amino acid brought into the process. Then a second tRNA brings another amino acid which matches its 3 anticodon bases with the second codon triplet of mRNA. An enzyme catalyses condensation between the amino acids.

Question 14

Peptide bond

Answer 14

The covalent bond between the two amino acids catlysed by an enzyme

Question 15

Translation step 2

Answer 15

Breaking bond between tRNA and amino acid it transferred in, not neede cause 2nd tRNa bonded to its own amino acid which is bonded to 1st amino acid. The 1st tRNA floats away into cytoplasm reloads with another amino acid of same type

Question 16

Translation step 3

Answer 16

The ribosome that has only one tRNA in it now moves one codon triplet down the mRNA molecule. The second tRNA is in the place of the first, there’s room for a 3rd to float in, with a 3rd specific amino acid then repetitive.

Question 17

The final codon triplet

Answer 17

A triplet that does not act as a code for an amino acid, it signals “stop” to the process of translation, the polypeptide breaks from the tRNA molecule and becomes a free floating polypeptide in the cytoplasm

Question 18

Polymerase chain reaction

Answer 18

DNA replication carried out artificially, only replicate short segments of DNA, scientist can produce huge numbers to analyse. Used for forensics, only limited dna found at crime scene.

Question 19

Taq DNA polymerase

Answer 19

An enzyme stable at high temperatures. Discovered from a bacterium called taq found in hot springs not denatured at high temperatures, used for discovery in gene technology.

Question 20

Genes

Answer 20

Instructions for proteins or messages, codes gor making polypeptides

Question 21

Genetic code

Answer 21

Sequence of bases which tells ribosomes which amino acid to use
64 different combinations infinite polypeptides

Question 22

Anti codons

Answer 22

Complementary base pairs to codons on mRNA

Question 23

General info summary

Answer 23

64 codons
20 amino acids
Same amino acid more than one codon

Question 24

Base substitution mutation

Answer 24

Reduced impact of wrongg base Amino acid produced could be the same

Question 25

Translation

Answer 25

The synthesis of polypeptides on ribosomes

Question 26

Transcription

Answer 26

The synthesis of mRNA

Question 27

Polypeptides

Answer 27

composed of amino acids covalently bonded together in a specific sequence