# data[].attributes.body
Transcription occurs in the nucleus for eukaryotes and in the nucleoid for prokaryotes in protein synthesis. DNA is decoded onto mRNA and eventually leaves through the nuclear pore and goes to a ribosome. Transcription replicates one of the two DNA strands known as the antisense strand or the template strand and is read in from 3’ to 5’,  mRNA to be made in the 5’ to 3’ direction. RNA polymerase binds to the promoter region of the gene and a chemical signal is sent to the transcription factors which causes them to activate and this causes it to unzip the DNA. Nucleotides are added from 5’ to 3’ direction according to the complementary base pairing. Nucleoside Triphosphate is used to power the transcription process.After, the mRNA will have a Methylated Cap at 5’ and poly-A tails at 3’ added. Spliceosomes splice out introns and connect exons. The introns which are non-coding will be cut out, leaving only the coding exons. Different combinations of exons on the same mRNA can result in different proteins due to alternative splicing. When RNA polymerase reaches a terminator sequence, transcription stops and the mRNA exits from the nucleus.

# data[].attributes.body
E site
A site
P site
tRNA
Amino Acids
Anticodon
Codon
AUG
ACC
Polysomes
ATP
rRNA
mRNA
Large Ribosomal Subunit
Small ribosomal subunit
Ribosome
20 amino acids
20 tRNA enzymes
Dephosphorylation of ATP
Initiation
Elongation
Termination
Initiation Factors
Guanosine Triphosphate
Polypeptide Chain
Translation Complex
Polypeptide chain
5’ to 3’
Peptide bonds
Stop codons
Start codons
Protein release factors

# data[].attributes.body
Translation occurs during interphase in the rough ER and in the cytoplasm. During Initiation, mRNA is attached to the binding site on the small subunit of a ribosome, and initiator tRNA goes to the P site, binding to the AUG sequence on the mRNA. The large subunit then attaches, creating the translation complex. During Elongation, tRNA continually adds an amino acid to the polypeptide chain as the ribosome moves along the mRNA strand in the 5' to 3' direction. Each time, the tRNA arrives at the A site, passes off the polypeptide chain at the P site, and exits the ribosome at the E site. Termination occurs once a stop codon has been reached. The polypeptide chain and tRNA detach from the mRNA and the ribosomal subunits separate.

# data[].attributes.body
Transcription occurs during interphase in the nucleus in eukaryotic cells. A bubble is created in a strand of DNA by RNA polymerase, and RNA polymerase synthesizes a strand of RNA using the DNA as a template according to complementary base pairing, except Thymine is replaced with Uracil.  This synthesis is initiated by when a protein binds to the promotor region, which is upstream from the gene being transcribed.  The silencer region, which causes transcription not to start, is also upstream, but the terminator region, which causes transcription to stop, is downstream from the gene. The new strand of RNA is called immature mRNA. Before it leaves the nucleus through the nuclear pores, it is given a methylated cap and a poly-A-tail, and its exons are spliced from its introns by spliceosomes and rearranged. After this process, the mRNA can be called mature mRNA.

# data[].attributes.body
DNA replication is a semiconservative process which occurs in the S phase of interphase. DNA gyrase makes it so the DNA does not supercoil, and then DNA helicase unzips the two strands, creating the Replication fork. Single stranded binding proteins keep the strands open as RNA primase attaches short strands of RNA (RNA primers). Based on the placement of the RNA primers, DNA polymerase III is able to begin synthesizing a new strand of DNA according the complementary base pairing, replicating in the 5' to 3' direction. Each nitrogenous base is attached to its complement on the antisense strand with hydrogen bonds. DNA polymerase II then removes the RNA primers and replaces them with DNA. Finally, DNA ligase seals the nick in the phospholipid backbone between the DNA that polymerase II and polymerase III synthesized. Because DNA must be synthesized in the 5' to 3' direction, one strand of DNA will not be made continuously, instead it will be synthesized in many short okazaki fragments which will later be attached to each other. The antisense strand of the okazaki fragments is called the lagging strand, and the one of the continuously made strand is called the leading strand. The process of replication occurs in many separate "bubbles" in eukaryotic cells, with replication forks making up their two sides. Eventually, these bubbles will run into neighboring ones and the whole strand will have been replicated.

# data[].attributes.body
Transcription is the process by which genes on the DNA are transcribed on mRNA. Eukaryotic organisms are organisms which contain a membrane bound nucleus and other membrane bound organelles. The first part of protein synthesis is transcription which takes place in the nucleus. Transcription in eukaryotic organisms consists in three steps, initiation, elongation, and termination. During initiation, transcription factors bind  “upstream” of the gene to the promoter region where RNA polymerase binds and initiates transcription. RNA polymerase unzips DNA into two strands, the sense strand and the antisense strand. The RNA polymerase reads  the template strand in a 3’ to 5’ direction in order to make mRNA in the 5’ → 3’ direction. During elongation, RNA Polymerase adds RNA nucleotides (which differ from DNA nucleotides by having Uracil instead of Thymine) using the antisense strand as a template. In order to power this process nucleoside triphosphate is used, where two phosphate groups are broken off, and the energy released fuels the transcription process.  When the RNA polymerase reaches the terminator sequence transcription ends and the mRNA detaches from the DNA. A terminator sequence is a nucleotide sequence in DNA which causes the RNA polymerase to stop transcription and detach. Before the mRNA strand leaves the nucleus it undergoes post-transcriptional modification where at the 5' end modified guanine nucleotide with 3 phosphates makes a cap called Methylated Cap. And at the 3' end  50- 250 repeated adenine nucleotides make a poly-A tail. The methylated cap and poly-A tail protect mRNA from degradation and help in translation process.

# data[].attributes.body
DNA replication happens during the S phase of interphase and is the process of replicating each strand of the double helix of each DNA molecule. Replication is semiconservative, meaning that two new strands are made using the old strands as templates. They are replicated in the 5’ to 3’ direction at all times. Replication always occurs at origins called origins of replication, which eukaryotic cells have a lot of because the amount of DNA that needs to be replicated is a lot more than that of prokaryotic cells. The first enzyme required for the separation of both strands is called DNA gyrase, it is the first enzyme and prevents the strands from supercoiling. Just behind it, DNA helicase breaks the hydrogen bonds between the complementary base pairs, thus, splitting the DNA strands apart. Finally, we have single-stranded binding proteins, which bind to the DNA strands and prevent them from reattaching. Then, RNA primase begins replication by adding an RNA primer to a DNA strand. This helps DNA polymerase III to know where to start adding nucleotides using the strand as a template. Since replication always happens in a 5’ to 3’ direction, one strand is being replicated continuously, thus, it’s called the leading strand, and the other strand is called the lagging strand, on which Okazaki fragments are made. These fragments only differ by the fact that each has to be replicated separately. After the nucleotides have been added, DNA polymerase I switches the RNA primer with the corresponding nucleotide. Finally, DNA ligase is another enzyme that seals up all of the nicks left within the sugar-phosphate backbone, and replication has been completed.

# data[].attributes.body
1. tRNA;
2. mRNA;
3. Amino acids;
4. Central dogma;
5. Cloverleaf structure;
5. 20 total amino acids;
6. mRNA binding site;
7. initiator tRNA;
8. MET amino acid;
9. Anticodon;
10. Codon;
11. tRNA activating enzymes;
12. Dephosphorylation;
13. ATP;
14. ADP;
15. Initiation factor proteins;
16. Stop codon;
17. Small ribosomal sub-unit;
18. Large ribosomal sub-unit;
19. Initiation;
20. UAC initiator anticodon;
21. AUG start codon;
22. Elongation;
23. Polypeptide chain;
24. Peptide bond;
25. Guanine triphosphate;
26. 5' --> 3';
27. E site;
28: P site;
29: A site;
30: Translation complex;
31: Termination;
32: UAG, UAA, UGA stop codon;
33: Protein release factors;
34: Enzyme substrate specificity;
35: Polysomes;
36: tRNA translocation;
37: Hydrogen bonds;
38: Ester bond (between amino acid and tRNA);
39: Intramolecular base pairing;
40: Amino acid binding site.

# data[].attributes.body
Exons
Introns
Spliceosomes
Adenine nucleotides
Nucleus
Methylated cap
Poly-A tails
pre-mRNA
Antisense strand
Sense strand
central dogma
Silencers
Template strand
RNA polymerase
RNA nucleotides
Coding strand
Terminator region
Promoter region
Repressor factors
Polypeptides
transcription factors
nucleoside triphosphate
terminator sequence
50- 250 repeated adenine nucleotides
Epigenome
Histone
Nucleotide
Regulating gene expression
Protein synthesis
Acetylation of histones
Epigenetics

# data[].attributes.body
The process begins with a section of DNA that needs to be replicated. Firstly, a DNA Gyrase enzyme binds to the strand, preventing it from supercoiling while a Helicase Enzyme separates the two strands apart - now creating a leading and lagging strand at the replication fork. They are broken up by breaking the different hydrogen bonds between the different nitrogenous bases. At the same time, binding proteins attach to the strand, preventing the two from reattaching. Now, RNA primase comes in and attaches to the strand, placing down a tiny strand of RNA called RNA primer. This primer then directs the DNA polymerase III where to start copying the DNA, which it does by adding nucleotides (through complementary base pairing) in the 5’ to 3’ direction. However, since one strand is in the 5’ to 3’ direction, new RNA ligase must be placed as the helicase continues to separate the strands - hence the name, replicating strand. As a result, Okazaki fragments are made. Once this has been completed, DNA Polymerase I comes in and removes the RNA primer which was placed down, replacing it with DNA. Finally, DNA ligase seals the nick in the phosphate backbone by forming phosphodiester bonds between the third carbon and the phosphate group.

# data[].attributes.body
DNA helicase
DNA gyrase
DNA Polymerase I
DNA Polymerase III
DNA Ligase
Okazaki fragments
Lagging strand
Leading Strand
5’ to 3’
3’ to 5’
Origin of replication
Replication Fork
Semi-Conservative model
Telomeres
Centromeres
Nucleotides ( A, T, C, G)
Complementary Base Pairing
Pyruvates and Pyrimidines
Parent Strand
Eukaryotic Chromosome
Prokaryotic Chromosome
RNA Primer
RNA primase
Hydrogen Bonds
Phospphodiester bonds
Binding Proteins

# data[].attributes.body
Translation is the second process of protein synthesis (also known as central dogma). Translation is the process by which ribosomes, tRNA and other proteins form polypeptide chains based on complementary code from mRNA. mRNA is transcribed from DNA in the nucleus and diffuses through the nuclear pores to reach the free floating ribosomes. A ribosome is composed of two parts, the large ribosomal subunit and the small ribosomal subunit. On the small ribosomal subunit the mRNA binding site can be found, where the mRNA will bond to and read in the 5’ to 3’ direction during translation. Within the large ribosomal subunit is the A-site, P-site, and E-site, where tRNA attaches to form a polypeptide. tRNA is composed of the same RNA nucleotides, but differs in structure to mRNA due to hydrogen bonds that form a clover leaf structure. tRNAs contain anti codons which will compliment the codon (3 base pairs) of the mRNA. One codon of mRNA codes for one amino acid which will attach to other amino acids by creating peptide bonds to make a polypeptide chain. tRNA carries a single amino acid, and is bonded with a specific amino acid due to 1 of 20 specific tRNA activating enzymes. These enzymes have an active site in which an amino acid, tRNA, and ATP bond, and through the process of ATP dephosphorylation the energy level of the amino acid is raised and attaches to the tRNA. Dephosphorylation is cause by the breaking of hydrogen bonds holding together ATPs phosphate groups which releases energy and causes ATP to turn into AMP. The energy transferred to the amino acid is later used in the formation of polypeptides. Translation is composed of three major stages: initiation, elongation and termination. During initiation the mRNA will first bind to the small ribosomal subunit where it’s codon will correlate to the P site of the large ribosomal subunit. Then the initiator tRNA (with anticodon UAC) will base pair with the codon of the mRNA. The codon AUG found on the mRNA is a start codon and codes for the amino acid methylamine (commonly known as met). Finally the large ribosomal subunit will bind to the small ribosomal subunit completing the complex. During intimation, Initiation factors (which are proteins) bring the components together, GTP (guanosine triphosphates) provide energy for the assembly, and the A site and E site are empty. The second step of translation is elongation where a repeated cycle that continually adds amino acids to create a polypeptide chain as the ribosome moves along the mRNA from 5’ to 3’. The cycle starts with a new tRNA’s anticodon base pairing with the mRNA codon on the A site of the ribosomal structure. Then a peptide bond is formed between the growing polypeptide and the new amino acid at A site, using the energy from the dephosphorylation of ATP. This is a condensation reaction. The tRNA at the P-site will then release the growing polypeptide giving it to the tRNA at the A site. Then the tRNA at the A site will be translocated to the P site, and the tRNA at the P site will be trans located to the E site where it will exit the translation complex. These steps are repeated until a stop codon is reached, and this is where termination occurs. The stop codons are the following: UAG, UAA, and UGA. What’s important to note about the stop codons is that the tRNA can not bind to them as there are no existing anti codons to pair with them. Since there are no anti codons, protein release factors bind to the A site causing the release of the polypeptide from the tRNA on the P site. Now all the components disassemble: the tRNA detaches from the P site, mRNA detaches from the small ribosomal subunit, and the large and small ribosomal subunits separate.

# data[].attributes.body
1. Central dogma

2. Polysomes

3. tRNA

4. Hydrogen bonds+Cloverleaf structure

5. Amino acid

6. Anticodon

7. Codon

8. Stop codon

9. Start Codon

10. Specific tRNA activating enzymes

11. 20 tRNA enzymes

12. 20 amino acids

13. ACC

14. AUG

15. ATP

16. Dephosphorylation of ATP

17. Ribosome

18. 5’-3’ direction

19. Large subunit

20. Small subunit

21. mRNA binding site

22. A site

23. E site

24. P site

25. Initiation

26. Elongation

27. Termination

28. Polypeptide chain

29. Peptide bond

30. Translation complex

31. Initiation factors

32. Guanine triphosphate

33. Translocation of the tRNA

34. Protein release factors

# data[].attributes.body
The central dogma is the process of creating proteins from DNA, also known as protein synthesis which occurs during the G1 or G2 phase of  interphase of cellular replication (mitosis or meiosis). This central dogma explains that DNA codes for RNA which codes for proteins. In other words, the genes found in DNA contain information which will then tell the cell to create specific proteins needed for cellular processes. The first part of protein synthesis is transcription which takes place in the nucleus where DNA is decoded onto mRNA which then leaves the nucleus through the nuclear pore. Unlike DNA replication, transcription only replicates one of the two DNA strands. This strand is known as the template strand or the antisense strand and is read in the 3’ to 5’ direction in order for mRNA to be made in the 5’ to 3’ direction. The other DNA strand which is not replicated but has the same sequence as mRNA (according to the complementary base pairing rule) is called the coding strand or the sense strand. DNA replication begins on the promoter region–upstream of the gene which needs to be replicated–which indicates where RNA polymerase should begin transcription. It is important to note that this promoter region is not transcribed. When the RNA polymerase binds to the promoter sequence a chemical signal activates protein transcription factors which will bind to the promoter sequence, allowing the polymerase to begin transcription. RNA polymerase will then initiate transcription by unzipping the DNA and adding nucleotides in the 5’ to 3’ direction according to complementary base pairing. During this process, free floating nucleoside triphosphate (which is a nucleotide with 3 phosphate groups) is used where two phosphates are broken off releasing the fuel needed for transcription. It is also important to note that instead of adding thymine nucleotides, RNA polymerase will add uracil nucleotides when pairing with adenine nucleotides. When RNA polymerase reaches the terminator region–downstream of the gene–it stops transcription by detaching itself from the template DNA strand. Once the mRNA has been created before it leaves the nucleus it must go through post-transcriptional modifications. This is made of two major steps. The first being the addition of a methylated cap at the 5’ end of the pre-mRNA and poly-A-tails at the 3’ which help protect mRNA from degrading . A methylated cap is simply a modified guanine nucleotide with 3 phosphates also known as guanine nucleoside triphosphate. A poly-A-tail is 50-250 repeated adenine nucleotides. The second major step is splicing. This is where spliceosomes, which are complex nuclear proteins combined with RNA, splice out introns and connect exons. A coding sequence is interrupted by introns which are non coding and will be cut out. The coding sequence, which are exons, are instead spliced together. Introns allow to break up the exons so that different patterns can be made from the same pre-mRNA. This is also known as alternative splicing, which allows for the regulation of gene expression.

# data[].attributes.body
1. codon
2. anticodon
3. sense strand
4. mRNA
5. Nuclear Pore
6. Ribosome
7. Pre mRNA
9. Nucleus
10. Central dogma
11. Promoter region
12. Transcription factors
13. Terminator region
14. Introns
15. Exons
18. Methylated cap
19. Poly-A tail
20. Antisense strand
21. 5' to 3'
22. Uracil
23. repressor factors
24. Regulating gene expression
25. RNA polymerase
26. repressor proteins
27. non-coding sequences
28. protein synthesis
29. Alternative splicing
30. Methylation of histones
31. histones
31. nucleosomes
33. Acetylation of histones
34. Epigenetics
35. Gene
36. Nucleoside Triphosphate
37. DNA
38. Phosphate groups
39. Covalent bonds
40. upstream of gene
41. silencer region
42. Initiation
43. Elongation
44. Termination

# data[].attributes.body
1. Pre mRNA

2. mRNA

3. Central dogma

4. Nucleus

5. Nuclear Pore

6. Interphase

7. Sense strand

8. Antisense strand

9. 5’ to 3’ direction

10. Uracil

11. Template strand

12. Coding strand

13. Antiparallel

14. Promoter region

15. Terminator region

16. Silencer region

17. Transcription factors

18. Repressor factors

19. Protein synthesis

20. RNA polymerase

21. RNA nucleotides

22. Nucleoside triphosphate

23. Methylated cap

24. Guanine nucleoside triphosphate

25. poly -A- tails

26. Adenine nucleotides

27. Gene expression regulation

28. Introns

29. Exons

30. Spliceosomes

31. Alternative mRNA splicing

# data[].attributes.body
DNA replication is the process of separating and replicating the double stranded helix of the DNA molecule. Since each DNA strand is separated and subsequently replicated, DNA replication is semiconservative, the two new strands made using the old strands as templates according to the complementary base pairing rule. Purines such as adenine and guanine form hydrogen bonds with the pyrimidines thymine and cytosine respectively. DNA strands are antiparallel and therefore only one strand can be replicated in the 5’ to 3’ direction. DNA replication begins on a DNA strand at points called origins of replication. Prokaryotes only have one point of origin whilst eukaryotes have many origins of replication. Replication starts with DNA gyrase, otherwise known as topoisomerase, which moves down the DNA molecule preventing supercoiling. DNA gyrase is followed by DNA helicase which breaks the hydrogen bonds between the nucleotides, splitting the DNA strands, forming a ‘fork’ in the DNA. Binding proteins ensure the strands do not reattach in the process of replication. RNA primase begins the replication of the parent strand by added a short section of RNA known as RNA primer which will guide the DNA polymerase III to bind and build the new DNA strand by adding nucleotides in a 5’ to 3’ direction using the parent strand as a template. DNA polymerase can only add nucleotides in the 5’ to 3’ direction, resulting in one strand being replicated continuously while the other is made in fragments. These short sections of nucleotides are known as okazaki fragments and assist in the replication of the lagging strand. After DNA polymerase III adds nucleotides to the new strand, DNA polymerase I attaches to the area of RNA primase and replaces the RNA fragment with DNA nucleotides. To complete the process, DNA ligase fills in the gap between the replaced RNA and the start point of the replicated strands, completing the process of replication.

# data[].attributes.body
Semiconservative DNA replication
Double stranded
Antiparallel strands
Replication fork
Parent strand
Leading strand
Lagging strand
Okazaki fragments
Complementary base pairing 
Nucleotides
5’ → 3’ direction
Origins of replication
Continuous replication
Discontinuous replication
Deoxyribonucleoside triphosphates
Hydrolysis of phosphate groups
Phosphodiester bonds
DNA gyrase
Topoisomerases 
DNA Helicase
Hydrogen bonding 
Binding proteins
RNA primase
RNA primer
DNA polymerase III
DNA polymerase I
DNA ligase
S phase 

# data[].attributes.body
Translation is the second phase of protein synthesis.
Before translation starts, tRNA activating enzymes are needed. These enzymes bind specific amino acids to ATP. Then, dephosphorylation of ATP happens, making ADP and releasing a lot of energy, thus, bonding the tRNA with the amino acid.
The first step of translation is initiation. During this process, the translation complex is assembled. First, proteins called initiation factors are released and the process starts. First, the mRNA binds to the mRNA binding site on the small ribosomal sub-unit, the UAC anticodon on the initiator tRNA binds to the AUG start codon on the mRNA, and finally the large ribosomal subunit binds to the tRNA.
The next step is elongation, during this step, amino acids are added to a chain of polypeptides using leftover energy from the dephosphorylation of ATP and GTP. This is a repeated cycle, which happens as the mRNA moves along in the 5' to 3' direction. Then tRNA binds to the A site in the large ribosomal sub-unit, when another tRNA comes along, it shifts to the P site, where the amino acid is bound to the next one with a peptide bond made from leftover energy and is detached from the tRNA. Finally, the tRNA moves to the E site, where it exits the translation complex. This is repeated until termination.
Termination is the detachment of the polypeptide chain and the dismemberment of the translation complex when either a UAG, UAA, or UGA stop codon is reached. Then, protein release factors bind to A-site on the large ribosomal subunit, preventing any tRNA from binding and causing the release of the polypeptide from tRNA at the P-site.

# data[].attributes.body
S-phase;
Nucleus;
Nucleoid;
Enzymes;
DNA Gyrase;
Helicase;
Single stranded binding protein;
DNA polymerase III;
RNA primer;
RNA primase;
DNA polymerase I;
Ligase;
Primer;
Nucleotides;
Double helix;
Leading strand;
Parent strand;
Lagging strand;
Phosphate backbone;
Nick;
Phosphodiester bond;
Origin of replication;
Semi-conservative;
Chromosomes;
Okazaki fragments;
Replication forks;
Complementary base pairing;
5'--> 3' direction;
Hydrogen bonds;
RNA nucleotides;
Deoxyribonucleotides;
Adenine, Guanine, Thymine, Cytosine;

# data[].attributes.body
Replication occurs in the s-phase of interphase, specifically in the cell's nucleus. DNA replication is semiconservative which means the strand is split into two and produces an original and new strand. The DNA strand unwinds/uncoils and the helicase enzyme unzips the strand by breaking the hydrogen bonds between the nitrogenous bases. Single stranded binding proteins keep the strands apart. DNA gyrase ensures that the strands don't supercoil. To synthesise a new strand, RNA primase adds a short length of RNA primer. The RNA primer indicates where DNA polymerase III needs to start adding nucleotides according to complementary base pairing in the 5' to 3' direction. DNA polymerase I removes the RNA primer and replaces it with DNA. Nucleotides Are being added towards the replication fork on the leading strand. On the lagging strand the same process occurs except in the 3' to 5' direction. Because of this Okazaki fragments are made, which short sections of DNA. Ligase seals up the nick in the phosphate backbone by connecting the nucleotides.

# data[].attributes.body
Semiconservative
S-phase
Nucleus
DNA gyrase
Helicase
RNA primase
RNA primer
DNA polymerase III
DNA polymerase I
Ligase
Okazaki fragments
Single stranded binding proteins
Leading strand
Lagging strand
Replication fork
Nucleic acid
Nucleotides
Nucleosomes
Histone proteins
H3 H4 H2A H2B H1
Phosphodiester bonds
Super coiling
Sugar phosphate backbone
Hydrogen bonds
Hydrolysis
Chromosomes
Parent strand
Complementary base pairing
Adenine, Thymine, Cytosine, Guanine

# data[].attributes.body
Template strand
Coding strand
tRNA
mRNA
Transcription factors
Silencer region
Promotor region
Terminator region
Repressor proteins
RNA polymerase
Methylated cap
Poly-A-tails
3 guanine triphosphate
Methylation
Immature mRNA
mature mRNA
Spliceosomes
Introns
Extrons

# data[].attributes.body
tRNA
Amino acids
Polypeptides
Peptide bond
Anticodons
5' to 3'
Ribosomal unit
Large subunit
Small subunit
mRNA binding site
tRNA binding site
E site
P site
A site
FEPA3
Codons
mature mRNA
immature mRNA
Complementary bases
ACC starting anticodons at 3' end
MET starting protein
Stop codon
Amino attachment site
Enzyme substrate specificity
GTP
ATP
Dephosphorylation
tRNA activating enzymes
Base sequences
Initiation
Elongation
Termination
Initiator tRNA
Protein release factors

# data[].attributes.body
Semiconservative
Replication fork
Lagging strand
Leading strand
Okazaki fragments
Replicated DNA
DNA gyrase
DNA helicase
RNA primer
primase
DNA polymerase III
DNA polymerase I
Binding proteins
Nucleus/nucleoid
S phase
RNA nucleotides
5' to 3'
Ligase
Parent strands
Complementary base pairing
Hydrogen bonds
Phosphodiester bonds

# data[].attributes.body
Translation is divided in three steps: initiation, elongation and termination

Initiation:

The translation complex is assembled. Initiation factors are required to bring all the components together. Guanine triphosphate is used to provide energy for this process. The mRNA binds to the mRNA binding site on the ribosomal subunit, the initiator tRNA binds its anticodon on the mRNA codon and the large subunit binds to the tRNA.
Elongation: amino acids are added to polypeptide chain as ribosomes move in the 5' - 3' direction.
Termination: the translation complex disassembles when a stop codon (UAG, UAA, UGA) is reached. Protein release factors bind to A-site on the large ribosomal subunit causing the release of the polypeptide from tRNA at the P-site.

# data[].attributes.body
Polysomes

tRNA

Amino acid

Anticodon

Codon

ACC

AUG

Specific tRNA activating enzymes

20 tRNA enzymes

20 amino acids

ATP

Dephosphorylation of ATP

Ribosome

Large subunit

Small subunit

mRNA binding site

A site

E site

P site

Initiation

Elongation

Termination

Translation complex

Initiation factors

Guanine triphosphate

Polypeptide chain

5’-3’ direction

Peptide bond

Translocation of the tRNA

Stop codon

Protein release factors

# data[].attributes.body
The first part of protein synthesis is transcription which occurs in the nucleus for eukaryotes and in the nucleoid for prokaryotes. DNA is decoded onto mRNA and eventually leaves through the nuclear pore and goes to a ribosome. Transcription always starts upstream of a gene. RNA polymerase binds to the promoter region of a gene and a chemical signal is sent so that transcription factors are activated. RNA polymerase then unzips the DNA. Then there is elongation of mRNA in which RNA polymerase adds nucleotides in the 5’-3’ direction. Nucleoside Triphosphate is used to power the transcription process. Methylated Cap (at 5’) and poly-A tails (at 3’) are added. Spliceosomes splice out introns and connect exons. Different combinations of exons on the same mRNA can result in different proteins due to alternative splicing. When RNA polymerase reaches a terminator sequence, transcription stops and the mRNA detaches from the DNA. If a repressor protein binds to a silencer region then transcription is prevented.

# data[].attributes.body
Template strand
Coding strand
Promoter region
Terminator region
Silencer region
Transcription factors
Repressor factors
RNA polymerase
RNA nucleotides
Nucleoside triphosphate
Nucleus 
Methylated cap 
Guanine +3 phosphates
poly -A- tails
Adenine nucleotides
Spliceosomes
Introns
exons

# data[].attributes.body
Dna gyrase doesn’t allow the strands to supercoil, then the helicase enzyme separates the strands by breaking the hydrogen bonds between the nitrogenous bases. The binding proteins do not allow the two strands to re-attach. The RNA primase attaches the RNA primer. The primer signals to the DNA polymerase III where to start copying the DNA. The DNA polymerase III copies the DNA strand by attaching the nucleotides in the direction 5’ to 3’. The DNA polymerase I substitutes the RNA primer with DNA, and lastly the DNA ligase seals the nick in the phosphate backbone by making the phosphodiester bonds between the third Carbon and the phosphate group.

# data[].attributes.body
Semiconservative DNA replication

Complementary base pairing A-T G-C

Okazaki fragments

Parent strand

Leading strand

Lagging strand

5’ → 3’ direction

Replication fork

Eukaryotic chromosomes, Origins of replication

Deoxyribonucleoside triphosphates

Hydrolysis of phosphate groups

Phosphodiester bonds

DNA gyrase

DNA Helicase

Hydrogen bonds

Binding proteins

RNA primase

RNA primer

DNA polymerase III

DNA polymerase I

DNA ligase