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O-Level Singapore/O-Level/Pure Physics Tuition/Physics Tutor

2014 Aug Combine Chemistry Intensive Revision

31-Jul Thu 5pm to 7pm 2 hrs Atomic Structure & Chemical Bonding

1-Aug Fri 6pm to 7.30pm 1.5 hrs Atomic Structure & Chemical Bonding

2-Aug Sat 7.30pm to 9.30pm 2 hrs Atomic Structure & Chemical Bonding

3-Aug Sun 9am to 10.30am 1.5 hrs Atomic Structure & Chemical Bonding

3-Aug Sun 2.30pm to 4pm 1.5 hrs Atomic Structure & Chemical Bonding

7-Aug Thu 5pm to 7pm 2 hrs Mole Calculation & P2 Exam Practice

8-Aug Fri 6pm to 7.30pm 1.5 hrs Mole Calculation & P2 Exam Practice

9-Aug Sat 7.30pm to 9.30pm 2 hrs Mole Calculation & P2 Exam Practice

10-Aug Sun 9am to 10.30am 1.5 hrs Mole Calculation & P2 Exam Practice

10-Aug Sun 2.30pm to 4pm 1.5 hrs Mole Calculation & P2 Exam Practice

14-Aug Thu 5pm to 7pm 2 hrs Acids and Bases & P1 Exam Practice

15-Aug Fri 6pm to 7.30pm 1.5 hrs Acids and Bases & P1 Exam Practice

16-Aug Sat 7.30pm to 9.30pm 2 hrs Acids and Bases & P1 Exam Practice

17-Aug Sun 9am to 10.30am 1.5 hrs Acids and Bases & P1 Exam Practice

17-Aug Sun 2.30pm to 4pm 1.5 hrs Acids and Bases & P1 Exam Practice

21-Aug Thu 5pm to 7pm 2 hrs Salts & P2 Exam Practice

22-Aug Fri 6pm to 7.30pm 1.5 hrs Salts & P2 Exam Practice

23-Aug Sat 7.30pm to 9.30pm 2 hrs Salts & P2 Exam Practice

24-Aug Sun 9am to 10.30am 1.5 hrs Salts & P2 Exam Practice

24-Aug Sun 2.30pm to 4pm 1.5 hrs Salts & P2 Exam Practice

28-Sep Thu 5pm to 7pm 2 hrs Organic Chemistry & P1 Exam Practice

29-Aug Fri 6pm to 7.30pm 1.5 hrs Organic Chemistry & P1 Exam Practice

30-Aug Sat 7.30pm to 9.30pm 2 hrs Organic Chemistry & P1 Exam Practice

31-Aug Sun 9am to 10.30am 1.5 hrs Oxidation and Reduction & P1 Exam Practice

31-Aug Sun 2.30pm to 4pm 1.5 hrs Organic Chemistry & P1 Exam Practice

2014 Aug Combine Physics Intensive Revision

29-Jul Tue 7pm to 9pm 2 hrs Sound & P1 Exam Practice

1-Aug Fri 4.30pm to 6pm 1.5 hrs Sound & P1 Exam Practice

3-Aug Sun 10.30pm to 12pm 1.5 hrs Kinematics and Dynamics & P1 Exam Practice

3-Aug Sun 1pm to 2.30pm 1.5 hrs Sound & P1 Exam Practice

5-Aug Tue 7pm to 9pm 2 hrs Light & P2 Exam Practice

8-Aug Fri 4.30pm to 6pm 1.5 hrs Light & P2 Exam Practice

10-Aug Sun 10.30pm to 12pm 1.5 hrs Forces and Moments & P2 Practice

10-Aug Sun 1pm to 2.30pm 1.5 hrs Light & P2 Exam Practice

12-Aug Tue 7pm to 9pm 2 hrs Electromagnetic Waves & Sound

15-Aug Fri 4.30pm to 6pm 1.5 hrs Electromagnetic Waves & Sound

17-Aug Sun 10.30pm to 12pm 1.5 hrs Energy, Work and Power & P1 Exam Practice

17-Aug Sun 1pm to 2.30pm 1.5 hrs Electromagnetic Waves & Sound

19-Aug Tue 7pm to 9pm 2 hrs Current Electricity & P2 Exam Practice

22-Aug Fri 4.30pm to 6pm 1.5 hrs Current Electricity & P2 Exam Practice

24-Aug Sun 10.30pm to 12pm 1.5 hrs Pressure & P2 Exam Practice

24-Aug Sun 1pm to 2.30pm 1.5 hrs Current Electricity & P2 Exam Practice

26-Aug Tue 7pm to 9pm 2 hrs D.C. Circuits & P1 Exam Practice

29-Aug Fri 4.30pm to 6pm 1.5 hrs D.C. Circuits & P1 Exam Practice

31-Aug Sun 10.30pm to 12pm 1.5 hrs Thermal Physics & P1 Exam Practice

31-Aug Sun 1pm to 2.30pm 1.5 hrs D.C. Circuits & P1 Exam Practice

If you need help in the O level combine Chemistry & Physics, please contact Angie @96790479 or Mr Ong 98639633

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O Level E Maths Tuition Singapore/Tuition O Level E Maths/Tutor

2014 Aug Elementary Mathematics Intensive Revision

28-Jul Mon 5pm to 6.30pm 1.5 hrs Algebraic Manipulation & P1 Exam Practice

30-Jul Wed 7pm to 8.30pm 1.5 hrs Algebraic Manipulation & P1 Exam Practice

31-Jul Thu 5.30pm to 7pm 1.5 hrs Algebraic Manipulation & P1 Exam Practice

4-Aug Mon 5pm to 6.30pm 1.5 hrs Functions and Graphs & P2 Exam Practice

6-Aug Wed 7pm to 8.30pm 1.5 hrs Functions and Graphs & P2 Exam Practice

7-Aug Thu 5.30pm to 7pm 1.5 hrs Functions and Graphs & P2 Exam Practice

10-Aug Sun 6pm to 7.30pm 1.5 hrs Functions and Graphs & P2 Exam Practice

11-Aug Mon 5pm to 6.30pm 1.5 hrs Quadratic Equations & P1 Exam Practice

13-Aug Wed 7pm to 8.30pm 1.5 hrs Quadratic Equations & P1 Exam Practice

14-Aug Thu 5.30pm to 7pm 1.5 hrs Quadratic Equations & P1 Exam Practice

17-Aug Sun 6pm to 7.30pm 1.5 hrs Quadratic Equations & P1 Exam Practice

18-Aug Mon 5pm to 6.30pm 1.5 hrs Properties of Circles & P2 Exam Practice

20-Aug Wed 7pm to 8.30pm 1.5 hrs Properties of Circles & P2 Exam Practice

21-Aug Thu 5.30pm to 7pm 1.5 hrs Properties of Circles & P2 Exam Practice

24-Aug Sun 6pm to 7.30pm 1.5 hrs Properties of Circles & P2 Exam Practice

25-Aug Mon 5pm to 6.30pm 1.5 hrs Pythagoras’ Theorem and Trigonometry

27-Aug Wed 7pm to 8.30pm 1.5 hrs Pythagoras’ Theorem and Trigonometry

28-Aug Thu 5.30pm to 7pm 1.5 hrs Pythagoras’ Theorem and Trigonometry

31-Aug Sun 6pm to 7.30pm 1.5 hrs Pythagoras’ Theorem and Trigonometry

For Exam based questions with full worked solution. Please contact Mr Ong @98639633

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O-Level Additional Mathematics Tuition Singapore

2014 Aug O level Additional Math Intensive Revision

28-Jul Mon 4pm to 5.30pm 1.5 hrs Surds and Indices and Logarithms

30-Jul Wed 7pm to 8.30pm 1.5 hrs Surds and Indices and Logarithms

31-Jul Thu 5.30pm to 7pm 1.5 hrs Surds and Indices and Logarithms

3-Aug Sun 6pm to 7.30pm 1.5 hrs Surds and Indices and Logarithms

4-Aug Mon 4pm to 5.30pm 1.5 hrs Co-ordinate Geometry & P2 Exam Practice

6-Aug Wed 7pm to 8.30pm 1.5 hrs Co-ordinate Geometry & P2 Exam Practice

7-Aug Thu 5.30pm to 7pm 1.5 hrs Co-ordinate Geometry & P2 Exam Practice

10-Aug Sun 6pm to 7.30pm 1.5 hrs Co-ordinate Geometry & P2 Exam Practice

11-Aug Mon 4pm to 5.30pm 1.5 hrs Trigonometric Identities and Eqns & P1 Exam Practice

13-Aug Wed 7pm to 8.30pm 1.5 hrs Trigonometric Identities and Eqns & P1 Exam Practice

14-Aug Thu 5.30pm to 7pm 1.5 hrs Trigonometric Identities and Eqns & P1 Exam Practice

17-Aug Sun 6pm to 7.30pm 1.5 hrs Trigonometric Identities and Eqns & P1 Exam Practice

18-Aug Mon 4pm to 5.30pm 1.5 hrs Differentiation and Application & P2 Exam Practice

20-Aug Wed 7pm to 8.30pm 1.5 hrs Differentiation and Application & P2 Exam Practice

21-Aug Thu 5.30pm to 7pm 1.5 hrs Differentiation and Application & P2 Exam Practice

24-Aug Sun 6pm to 7.30pm 1.5 hrs Differentiation and Application & P2 Exam Practice

25-Aug Mon 4pm to 5.30pm 1.5 hrs Integration and Application & P1 Exam Practice

27-Aug Wed 7pm to 8.30pm 1.5 hrs Integration and Application & P1 Exam Practice

28-Aug Thu 5.30pm to 7pm 1.5 hrs Integration and Application & P1 Exam Practice

31-Aug Sun 6pm to 7.30pm 1.5 hrs Integration and Application & P1 Exam Practice

For exam based question with full worked solution, please contact
@9863 9633

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O Level Chemistry Tuition Singapore/Chemistry O Level Tuition/Tutor

31-Jul Thu 5pm to 7pm 2 hrs Atomic Structure & Chemical Bonding

1-Aug Fri 6pm to 7.30pm 1.5 hrs Atomic Structure & Chemical Bonding

2-Aug Sat 7.30pm to 9.30pm 2 hrs Atomic Structure & Chemical Bonding

3-Aug Sun 9am to 10.30am 1.5 hrs Atomic Structure & Chemical Bonding

3-Aug Sun 2.30pm to 4pm 1.5 hrs Atomic Structure & Chemical Bonding

7-Aug Thu 5pm to 7pm 2 hrs Mole Calculation & P2 Exam Practice

8-Aug Fri 6pm to 7.30pm 1.5 hrs Mole Calculation & P2 Exam Practice

9-Aug Sat 7.30pm to 9.30pm 2 hrs Mole Calculation & P2 Exam Practice

10-Aug Sun 9am to 10.30am 1.5 hrs Mole Calculation & P2 Exam Practice

10-Aug Sun 2.30pm to 4pm 1.5 hrs Mole Calculation & P2 Exam Practice

14-Aug Thu 5pm to 7pm 2 hrs Acids and Bases & P1 Exam Practice

15-Aug Fri 6pm to 7.30pm 1.5 hrs Acids and Bases & P1 Exam Practice

16-Aug Sat 7.30pm to 9.30pm 2 hrs Acids and Bases & P1 Exam Practice

17-Aug Sun 9am to 10.30am 1.5 hrs Acids and Bases & P1 Exam Practice

17-Aug Sun 2.30pm to 4pm 1.5 hrs Acids and Bases & P1 Exam Practice

21-Aug Thu 5pm to 7pm 2 hrs Salts & P2 Exam Practice

22-Aug Fri 6pm to 7.30pm 1.5 hrs Salts & P2 Exam Practice

23-Aug Sat 7.30pm to 9.30pm 2 hrs Salts & P2 Exam Practice

24-Aug Sun 9am to 10.30am 1.5 hrs Salts & P2 Exam Practice

24-Aug Sun 2.30pm to 4pm 1.5 hrs Salts & P2 Exam Practice

28-Sep Thu 5pm to 7pm 2 hrs Organic Chemistry & P1 Exam Practice

29-Aug Fri 6pm to 7.30pm 1.5 hrs Organic Chemistry & P1 Exam Practice

30-Aug Sat 7.30pm to 9.30pm 2 hrs Organic Chemistry & P1 Exam Practice

31-Aug Sun 9am to 10.30am 1.5 hrs Oxidation and Reduction & P1 Exam Practice

31-Aug Sun 2.30pm to 4pm 1.5 hrs Organic Chemistry & P1 Exam Practice

If you need help in the O level Chemistry, please contact Angie @96790479 or Mr Ong 98639633

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O-Level Singapore/O-Level/Pure Physics Tuition/Physics Tutor

2014 Aug O level Physics Intensive Revision

29-Jul Tue 7pm to 9pm 2 hrs Sound & P1 Exam Practice

1-Aug Fri 4.30pm to 6pm 1.5 hrs Sound & P1 Exam Practice

3-Aug Sun 10.30pm to 12pm 1.5 hrs Kinematics and Dynamics & P1 Exam Practice

3-Aug Sun 1pm to 2.30pm 1.5 hrs Sound & P1 Exam Practice

5-Aug Tue 7pm to 9pm 2 hrs Light & P2 Exam Practice

8-Aug Fri 4.30pm to 6pm 1.5 hrs Light & P2 Exam Practice

10-Aug Sun 10.30pm to 12pm 1.5 hrs Forces and Moments & P2 Practice

10-Aug Sun 1pm to 2.30pm 1.5 hrs Light & P2 Exam Practice

12-Aug Tue 7pm to 9pm 2 hrs Electromagnetic Waves & Sound

15-Aug Fri 4.30pm to 6pm 1.5 hrs Electromagnetic Waves & Sound

17-Aug Sun 10.30pm to 12pm 1.5 hrs Energy, Work and Power & P1 Exam Practice

17-Aug Sun 1pm to 2.30pm 1.5 hrs Electromagnetic Waves & Sound

19-Aug Tue 7pm to 9pm 2 hrs Current Electricity & P2 Exam Practice

22-Aug Fri 4.30pm to 6pm 1.5 hrs Current Electricity & P2 Exam Practice

24-Aug Sun 10.30pm to 12pm 1.5 hrs Pressure & P2 Exam Practice

24-Aug Sun 1pm to 2.30pm 1.5 hrs Current Electricity & P2 Exam Practice

26-Aug Tue 7pm to 9pm 2 hrs D.C. Circuits & P1 Exam Practice

29-Aug Fri 4.30pm to 6pm 1.5 hrs D.C. Circuits & P1 Exam Practice

31-Aug Sun 10.30pm to 12pm 1.5 hrs Thermal Physics & P1 Exam Practice

31-Aug Sun 1pm to 2.30pm 1.5 hrs D.C. Circuits & P1 Exam Practice

If you need help in the above topics, please contact Angie @96790479 or Mr Ong @98639633

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A-Level Mathematics Tuition Singapore/JC Maths/H2 Math Tuition and Tutor

2014 Aug A level Math Intensive Revision

28-Jul Mon 7.30pm to 9.30pm 2 hrs Differentiation & Applications

29-Jul Tue 5pm to 7pm 2 hrs Inequalities/Conics/Differentiation/Integration

2-Aug Sat 11am to 1pm 2 hrs Inequalities/Conics/Differentiation/Integration

2-Aug Sat 5.30pm to 7.30pm 2 hrs Differentiation & Applications

3-Aug Sun 10am to 12pm 2 hrs Differentiation & Applications

3-Aug Sun 4pm to 6pm 2 hrs Inequalities/Conics/Differentiation/Integration

4-Aug Mon 7.30pm to 9.30pm 2 hrs Differentiation & Applications Exam FAQ

5-Aug Tue 5pm to 7pm 2 hrs Complex Numbers

9-Aug Sat 11am to 1pm 2 hrs Complex Numbers

9-Aug Sat 5.30pm to 7.30pm 2 hrs Differentiation & Applications Exam FAQ

10-Aug Sun 10am to 12pm 2 hrs Differentiation & Applications Exam FAQ

10-Aug Sun 4pm to 6pm 2 hrs Complex Numbers

11-Aug Mon 7.30pm to 9.30pm 2 hrs AP & GP

12-Aug Tue 5pm to 7pm 2 hrs Complex Numbers Exam FAQ

16-Aug Sat 11am to 1pm 2 hrs Complex Numbers Exam FAQ

16-Aug Sat 5.30pm to 7.30pm 2 hrs AP & GP

17-Aug Sun 10am to 12pm 2 hrs AP & GP

17-Aug Sun 4pm to 6pm 2 hrs Complex Numbers Exam FAQ

18-Aug Mon 7.30pm to 9.30pm 2 hrs Series and Sequences

19-Aug Tue 5pm to 7pm 2 hrs Permutations and Combinations

23-Aug Sat 11am to 1pm 2 hrs Permutations and Combinations

23-Aug Sat 5.30pm to 7.30pm 2 hrs Series and Sequences

24-Aug Sun 10am to 12pm 2 hrs Series and Sequences

24-Aug Sun 4pm to 6pm 2 hrs Permutations and Combinations

25-Aug Mon 7.30pm to 9.30pm 2 hrs Graphing Techniques

26-Aug Tue 5pm to 7pm 2 hrs Probalility

30-Aug Sat 11am to 1pm 2 hrs Probalility

30-Aug Sat 5.30pm to 7.30pm 2 hrs Graphing Techniques

31-Aug Sun 10am to 12pm 2 hrs Graphing Techniques

31-Aug Sun 4pm to 6pm 2 hrs Probalility

Please contact Mr Ong @98639633 if you need help in Mathematics

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A-Level Economics Tuition Singapore/H2/H1 Economics Tuition

Microeconomics Revision 2 : Demand, Supply and the Market Part 1

Syllabus Content :
• The individual and market demand curves as representations of intentions to consume.
• The firm and market supply curves as representations of intentions to consume.
• Changes in demand and supply.
• Shifts vs movements in demand and supply.
• Equilibrium price and quantity

Learning Outcome :
• Explain that demand reflects consumers’ satisfaction and recognize the inverse relationship between price and quantity demanded.
• Explain that supply reflects opportunity costs and recognize the direct relationship between price and quantity supplied.
• Discuss the factors affecting demand and supply and the implications of the ceteris paribus condition.
• Differentiate between shift and movements along the demand and supply curves.
• Explain the determination of market equilibrium price and quantity through the interaction of demand and supply.
• Analyse the effects of changes in demand and supply on equilibrium price and output.

Content Quiz :

1. List the main influences on demand for a good.
2. List the main influences on supply of a good.
3. Define demand.
Demand is a relationship indicating the quantity of a well-defined good (or service) that consumers are both willing and able to buy at each possible price during a given period of time, ceteris paribus. It is sometimes known as Effective Demand, or a desire backed by purchasing power.
4. Define supply.
Supply is a relationship indicating the quantity of a well-defined good (or service) that producers are both willing and able to put up for sale at each possible price during a given period of time, ceteris paribus.
5. What does the law of demand say?
The law of demand states that in a given time period, the quantity demanded of a good (or service) is inversely related to its price, ceteris paribus.
6. Why do consumers demand less of a good when its price increases?
Consumers demand less of a good (or service) when price increases because of 2 reasons :

• People will feel poorer. They will not be able to afford to buy so much of the good with their money. The purchasing power of their income has fallen. This is called the income effect of a price rise.
• The good will now be more expensive relative to other goods. People will thus switch to alternative or “substitute” goods. This is called the substitution effect of a price rise.

7. What does the law of supply say?
The law of supply states that in a given time period, the quantity supplied of a good (or service) is directly related to its price, ceteris paribus.
 
8. Why do suppliers supply more of a good when its price increases?
Producers/Firms supply more of a good (or service) when price increases because of 3 reasons :

• As firms supply more, they are likely to find that beyond a certain level of output, costs rise more and more rapidly. Only if the price rises will it be worth producing more and incurring these higher costs.
• The higher the price of the good, the more profitable it becomes to produce. Firms will thus be encouraged to produce more of it by switching from the production of less profitable goods.
• Given time, if the price of a good remains high, new producers will be encouraged to set up in production assuming there are no barriers to entry. Total market supply thus rises.

9. What is the link between individual demand/supply and market demand/supply?
Horizontal summation
10. What is the difference between change in quantity demanded/supplied and change in demand/supply? Draw diagrams to illustrate.

Please contact Angie Hp 96790479 or Mr Ong 98639633 if you need help in Economics and complete Notes

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A-Level Physics Tuition Singapore/H2 Physics Tuition/JC Physics Tutor

Hi A-level/H2/JC Physics Tuition students

2014 Aug A level Physics Intensive Revision

31-Jul Thu 7.30pm to 9.30pm 2 hrs Electromagnetism/EMI/AC

2-Aug Sat 9am to 11am 2 hrs Electromagnetism/EMI/AC

2-Aug Sat 7.30pm to 9.30pm 2 hrs Waves

3-Aug Sun 12pm to 2pm 2 hrs Waves

3-Aug Sun 2pm to 4pm 2 hrs Electromagnetism/EMI/AC

7-Aug Thu 7.30pm to 9.30pm 2 hrs Direct Current & Current of Electricity

9-Aug Sat 9am to 11am 2 hrs Direct Current & Current of Electricity

9-Aug Sat 7.30pm to 9.30pm 2 hrs Oscillations

10-Aug Sun 12pm to 2pm 2 hrs Oscillations

10-Aug Sun 2pm to 4pm 2 hrs Direct Current & Current of Electricity

14-Aug Thu 7.30pm to 9.30pm 2 hrs Quantum/Nuclear/Planning

16-Aug Sat 9am to 11am 2 hrs Quantum/Nuclear/Planning

16-Aug Sat 7.30pm to 9.30pm 2 hrs Superposition 1

17-Aug Sun 12pm to 2pm 2 hrs Superposition 1

17-Aug Sun 2pm to 4pm 2 hrs Quantum/Nuclear/Planning

21-Aug Thu 7.30pm to 9.30pm 2 hrs Lasers and Semiconductors

23-Aug Sat 9am to 11am 2 hrs Lasers and Semiconductors

23-Aug Sat 7.30pm to 9.30pm 2 hrs Superposition 2

24-Aug Sun 12pm to 2pm 2 hrs Superposition 2

24-Aug Sun 2pm to 4pm 2 hrs Lasers and Semiconductors

28-Aug Thu 7.30pm to 9.30pm 2 hrs Planning

30-Aug Sat 9am to 11am 2 hrs Planning

30-Aug Sat 7.30pm to 9.30pm 2 hrs Forces and Work Done, Energy, Power

31-Aug Sun 12pm to 2pm 2 hrs Forces and Work Done, Energy, Power

31-Aug Sun 2pm to 4pm 2 hrs Planning

If you need help in Physics please contact Mr Ong @98639633

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A-Level Biology Tuition Singapore/H2 Biology Tuition/JC Biology Tutor

TOPIC 2: DNA AND GENOMICS – Part 3

LEARNING OUTCOME

c)Describe how the information on DNA is used to synthesise polypeptides in prokaryotes and eukaryotes. (Description of the processes of transcription, formation of mRNA from premRNA and translation is required.)

ESSAY ANSWER

TRANSCRIPTION
Transcription is the process by which RNA is synthesized from DNA within the nucleus. The synthesis of RNA begins in the nucleus of a living cell that is not undergoing cell and nuclear division. Within the nucleus, messenger RNA (mRNA) is transcribed from the template DNA strand of a gene in three main phases: Initiation, Elongation and Termination.

INITIATION:
In prokaryotes, transcription is initiated when RNA polymerase binds to the pribnow box in the promoter. In eukaryotes, transcription is initiated when general transcription factors bind to the TATA box of the promoter. This facilitates the binding of RNA polymerase to the promoter. In eukaryotes, RNA Polymerase I transcribes rRNA, RNA polymerase II transcribes mRNA and RNA Polymerase III transcribes
tRNA. In both prokaryotes and eukaryotes, RNA polymerase unwinds both strands of DNA apart for elongation.

ELONGATION:
RNA polymerase adds ribonucleotides through complementary base-pairing rules: A – U; C- G. RNA Polymerase also catalyse the formation of phosphodiester bonds between ribonucleotides. mRNA is synthesized in the 5’
3’ direction. 5’
3’elongation of the mRNA strand occurs until the transcription stop site is reached.

TERMINATION:
In prokaryotes, transcription proceeds through a terminator sequence in the DNA.The transcribed termination (an RNA sequence) functions as the termination signal,causing the polymerase to detach from the DNA and release the transcript, which is available for immediate use as mRNA. In eukaryotes, RNA polymerase II transcribes a sequence on the DNA called the polyadenylation signal (AAUAAA) in the pre-mRNA. Then, at a point about 10 to 35 nucleotides downstream from the AAUAAA signal,proteins associated with the growing RNA transcript cut it free from the polymerase,releasing the pre-mRNA.

POST-TRANSCRITIONALMODIFICATION of pre-mRNA
In eukaryotes, mRNA undergoes post-transcriptional modification. A 5’ cap consisting of 7-methyguanosine is added to the 5’ end of pre-mRNA. This is followed by RNA splicing. Finally, a poly-A tail is added to the pre-mRNA. RNA splicing is carried out by spliceosomes, which is a complex of small ribonucleoproteins (snRNPs), at the specific splice sites. In this process, the noncoding introns are removed and exons are spliced together. The addition of poly-A tail is catalysed by poly-A polymerases. The 5’ cap and poly-A tail protects the mRNA from degradation by nucleases. Also, both are needed for ribosomal binding. The poly-A tail also directs the mRNA from the nucleus to the cytoplasm for translation.

TRANSLATION
Translation is the process where mRNA is used as a template for the synthesis of a polypeptide.

ACTIVATION OF AMINO ACIDS:
Aminoacyl-tRNA synthetase attaches the correct amino acid to its tRNA, based on its codon sequence.

INITIATION:
The small subunit of the ribosome recognizes and binds to the 5’ end of the mRNA. This is followed by the binding of initiator tRNA with amino acid methionine to the start codon, The initiator tRNA has the anticodon sequence UAC, complementary to that of the start codon, AUG. Finally, the arrival of the large subunit completes the translation initiation complex. GTP provides energy for the formation of this complex.

ELONGATION:
The initiator tRNA carrying methionine is at the P site. The next tRNA with an anticodon sequence complementary to that of the codon at the A site, binds to the Asite.GTP is required for codon-recognition. Peptidyl transferase catalyzes the transfer of amino acid on the P-site to the amino acid on the A-site, forming a peptide bond between them. This is followed by the shift of the ribosome by one codon downstream. The initiator tRNA is now at the E site, and the second tRNA is now at the
P site. GTP drives the translocation process. The tRNA on the E-site is now free to exit the ribosome. The A-site is now available for the next tRNA.

TERMINATION:
Elongation of the polypeptide continues until the ribosome reaches a termination codon (UAA, UAG or UGA). The A-site accepts a protein called a release factor instead of a tRNA at the stop codon. The release factor causes the addition of water instead of an amino acid to the polypeptide chain. This causes the hydrolysis of the polypeptide chain from the tRNA at the P-site, with the provision of energy by GTP.

Polyribosomes may trail along the same mRNA.

For exam based questions and solutions, please contact Hp @9863 9633

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A Level GP/General Paper Tuition Singapore

E-GP Review

One.Tuition Place General Paper E-Review Service
Require a GP Tutor’s opinion of your essay?
Require a detailed analysis of your Essay and suggested improvement tips?
From Only S$5 per essay marked by our GP Tutor in within 24h
Click here to view a sample of an essay reviewed

Please contact Angie @96790479 or Mr Ong @98639633

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A-Level Chemistry Tuition Singapore/H2 Chemistry Tuition/JC Chemistry Tutor

Chemical Bonding

IONIC OR ELECTROVALENT BONDING

Formation of Ionic Bonds
An ionic bond is the electrostatic force of attraction between two oppositely charged ions, which are formed by the transfer of electrons from one atom (usually metallic) to another
(usually non-metallic).

Metallic atoms usually have 1 to 3 valence electrons. By losing these valence electrons, they achieve a stable octet (noble gas) electronic configuration, forming positively-charged cations.

Non-metallic atoms usually have 4 to 8 valence electrons. Atoms of elements from Group V to Group VII tend to accept electrons to form negatively-charged anions that have octet configurations.

Ionic Bond Strength

Ionic bonds are generally strong forces of attraction and a lot of energy is required to break such bonds.

The strength of an ionic compound is indicated by its lattice energy. Lattice energy is defined as “the energy released when one mole of an ionic crystalline solid is formed from its constituent gaseous ions”. For example, lattice energy of NaCl is equal to the heat released for the equation: Na+(g) + Cl–(g) NaCl(s). The lattice energy is exothermic since it arises from the attraction between oppositely charged ions.

Note:
• Attraction between unlike charges results in stabilisation and energy is given out.
• The greater the attraction, the greater will be the amount of energy given out.
• Conversely, repulsion between like charges results in destabilisation and energy is taken in.

In general, the greater the magnitude of the lattice energy, the stronger the ionic bond

Structure of an Ionic Compound

In an ionic compound, constituent ions are held in fixed positions in an orderly arrangement by strong ionic bonds.

If you need complete note and more exam based questions with full worked solution, please contact @9863 9633

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O-Level Additional Mathematics Tuition Singapore

Partial fractions

1/(X+a)(X+b) = A/(X+a) + B/(X+b)

1/(X+a)^2 = A/(X+a)^2 + B/(X+b)

1/(aX^2+b)(X+c) = (AX + B)/(aX^2+b) + C/(X+c)

Note
a,b,c,A.B,C, are constant

For exam based question with full worked solution, please contact
@9863 9633

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O Level E Maths Tuition Singapore/Tuition O Level E Maths/Tutor

Factorisation

1. Factorisation of algebraic expressions can be done by

i. taking out common factors from all terms in the given expressions

ii. grouping the terms such that the new terms obtained have a common factor

iii. using the “cross” method for quadratic expressions

2. If two factors A and B are such that A x B = 0, then, either A = 0, or B = 0, or both A and B = 0. This principal is used to find the unknown in quadratic equations.

Example 1
16a^2 – 9
= (4a)^2 – 3^2
= (4a + 3)(4a – 3)

Example 2
d^2-1+4d+4
= (d-1)(d+1)+ 4(d+1)
=(d+1)(d-1 +4)
=(d + 1 )(d + 3)

Example 3
4xy + 8y – 5x – 10
= 4y(x + 2) – 5(x + 2)
= (x + 2)(4y – 5)

Example 4
3a^2 – a -10
= (3a + 5) (a – 2)

For Exam based questions with full worked solution. Please contact Mr Ong @98639633

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O-Level Singapore/O-Level/Physics and Chemistry Tuition/Physics Tutor

Elements, Compounds and Mixtures

Do you know?
All metals exist as atoms. Most non-metals exist as molecules

Do you know?
Many non-metallic elements exist as molecules. For example, hydrogen and oxygen exist as H2, and 02 molecules respectively

Do you know?
Tap water is not a pure compound. It is a mixture that contains water and dissolved substances such as chlorine and other minerals.

If you need help in the O level Chemistry, please contact Angie @96790479 or Mr Ong 98639633

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O Level Chemistry Tuition Singapore/Chemistry O Level Tuition/Tutor

Elements, Compounds and Mixtures

Do you know?
All metals exist as atoms. Most non-metals exist as molecules

Do you know?
Many non-metallic elements exist as molecules. For example, hydrogen and oxygen exist as H2, and 02 molecules respectively

Do you know?
Tap water is not a pure compound. It is a mixture that contains water and dissolved substances such as chlorine and other minerals.

If you need help in the O level Chemistry, please contact Angie @96790479 or Mr Ong 98639633

[Author]

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