Tuesday, November 24, 2009

[Biology Form 4] Enzymes Extraordinaire II


D is for definition
4. Define enzyme
An enzyme is a biological catalyst that speeds up the rate of chemical reactions occurring in living organisms.

D is also for definition (The Where question)
5. Where are enzymes synthesised in a cell?
In ribosomes.

6. Where are enzymes modified and packaged in a cell?
In the Golgy body.

E is for examples and effects
7. Example: State an example of enzymes involved in the digestion or hydrolysis of each of the following substrates:
a) Starch - Amylase
b) Proteins - Pepsin
c) Fats - Lipase
d) Maltose - Maltase
e) Lactose - Lactase
f) Sucrose - Sucrase
g) Cellulose - Cellulase

8. Effect: What would be the effect on digestion if enzymes were unavailable?
Digestion would be slowed down drastically.

F is for factors
9. State four factors that affect enzyme activity.
Temperature, pH, enzyme concentration and substrate concentration.

G is for graphs
10. Sketch a graph for each of the factors on enzyme activity. Label the x-axis and y-axis correctly.

Monday, November 23, 2009

[Biology Form 4] Human Respiratory System - The Network Within

Our lungs are the organs that bring in oxygen into our body. In them are thousands of branch-like, tiny tubules, called bronchioles, which are connected to millions of air sacs known as alveoli.

A dense network of blood capillaries is found on the surface of each alveolus. When oxygen from the air that we breathe in enters the air sacs, it diffuses into these blood capillaries.

At the same time, carbon dioxide from the blood diffuses out into the alveoli before we breathe it out.


The pathway of air: nasal cavities (or oral cavity) -> pharynx -> trachea -> right and left bronchi -> bronchioles -> alveoli (site for gaseous exchange in which oxygen enters and crbon dioxide leaves our lungs).


Notes:
  • The are some 300 million alveoli in our two adult lungs. These provide a surface area of some 160m2 (almost 80 times the area of our skin).

  • Only a fraction of the oxygen we inhale is taken up by the lungs.

Maths And Science Classes: A Lesson Learned

NST

2009/11/23

From B. Suresh Ram in Bandung

THE Education Ministry may emulate the model used by Chinese schools for the teaching of Mathematics and Science in national schools.

This followed the good results achieved by Chinese schools in the two subjects in the recent Ujian Pencapaian Sekolah Rendah (UPSR), Deputy Prime Minister Tan Sri Muhyiddin Yassin said.

Muhyiddin, who is also education minister, said Education directorgeneral Tan Sri Alimuddin Mohd Dom would review and study the performance of pupils in national and vernacular schools, as well as in urban and rural schools.

“We may emulate this (vernacular schools’ model) in national schools,” he said at the end of his three-day working visit here.

He was commenting on the UPSR results announced last week.

Research showed that Chinese schools emphasised practical work for pupils, especially homework.

Discipline is also the utmost in these schools.

Activities and sports in these schools also helped build pupils’ IQ and EQ (emotional intelligence quotient).

Muhyiddin said it was also essential to address the performance gap between rural and urban school pupils.

“There is still a gap. We need to analyse this and find ways to close this gap.” He, however, said he was encouraged by the improved results.

Overall, pupils, especially those in rural schools, showed an improvement.

A total of 48,171 pupils, or 9.51 per cent of 506,620, who sat the exam scored straight A s.

Last year, 46,641 (9.19 per cent) of 507,320 UPSR candidates scored all As.

The number of pupils with good results (minimum C) also increased to 63.03 per cent compared with 62.56 per cent last year, while only 0.64 per cent scored all Es compared with 0.66 per cent last year.

Overall, the gap between rural and urban pupils was narrowing.

This could be seen in the contraction in the overall achievement disparity between rural and urban pupils.

The gap between the number of rural and urban pupils scoring five As this year was 3.64 per cent compared with 4.22 per cent last year.

The gap in the number of pupils who obtained good results between the two areas was 5.55 per cent this year compared with 6.25 per cent last year.

Thursday, November 19, 2009

Found: Schoolkids who got lost in Gunung Lambak

The Star

KLUANG: Four students of SM Sultan Abdul Jalil who lost their way while climbing Gunung Lambak here on Tuesday were found by a rescue team on Wednesday.

The four students, Meor Shahidan Meor Azman, Normayzurah Nor Salam, Nor Fazlin Mohd Zin and Nurul Afiqah Zulkiflee, all aged 13, were found by a General Operations Force (GOF) team at about 1.35pm.

Kluang district Safety Committee chairman Abdul Razak Mohd Salleh said the four Form One students, who had started climbing the 510m high mountain at about 10am on Tuesday, realised that they had lost their way at about 2pm.

“It was not a school trip. They had decided to climb the mountain on their own. Realising that they had lost their way, one of them contacted a family member via a handphone,” he told reporters here.

He added that the rescue operation team which comprised 60 members from the army, GOF, Civil Defence Department, Rela and the Fire and Rescue Department, started the search at 4pm Tuesday when the four could not be contacted after their handphones ran out of power.

Abdul Razak, who is also the Kluang district officer, said the search and rescue operation continued their search throughout Tuesday night before they were found near Kampung Datuk Abdul Rahman Yassin.

He added that though the students were pale and weak, none of them suffered any injuries; they were however sent to the Kluang Hospital for observation. -- Bernama

Tuesday, November 17, 2009

Wish You A Good Luck

A best of luck to all 'SPM & STPM 2009' candidates...

May Allah bless you...

Please also remember to get a bless from your:
  1. Teachers,
  2. Mother &
  3. Father
Then, DO THE BEST!!!

[Biology SPM] Exam Pointers IV

Source: Maths & Science Guide

Revision
Describe the process of digestion. [ 2 marks ]

Correct Answers
A process in which complex organic food is broken down through physical and chemical processes into simple soluble molecules that can be easily absorbed by the cells.

Comments:
Include "physical processes" (involving mastication and churning processes) and "chemical processes" ( involving the action of enzymes) in your complete description of the process. Note that food should be referred to as "complex organic food", and that it is broken down into "simple soluble molecules".

[Physics SPM] Exam Pointers V

Source: Maths & Science Guide

Revision
Explain how upthrust is produced during the flight of an aeroplane. [ 5 marks ]

Frequent Mistakes
Student's Answer:
Upthrust is produced based on the Bernoulli's principle, which states that a low pressure is generated at the point where a fluid travels at high speed. Hence, when the air flows at high speed, a low pressure is generated and subsequently produces a net forces that acts upwards on the aeroplane. This net force constitutes the upthrust.

Comments:
The command word is "explain", and the objective of the question refers to how the upthrust is produced. Since the allocation of marks is five, the answer should consist of five main points. The student has identified the command word as well as the objective of the question. However, the lengthy statements cause the answer to stray away from the objective. Also, even though the answer mentions that air flows at high speed, it does not state where - above or below the wings or body of the aeroplane. Hence, the explanation is inaccurate.

Correct Answers
  • The shape of an aeroplane is that of an aerofoil.
  • This shape ensures the speed of air is higher above the wings and body of the plane than that under them.
  • Based on the Bernoulli's principle, the air pressure under the plane is higher that the above it.
  • Hence, a net force that acts upwards is generated on the aeroplane.
  • This provides the upthrust that lifts the plane during its flight.

Monday, November 16, 2009

[Physics SPM] Exam Pointers IV

Source: Maths & Science Guide

Revision
State the factors that influence the accuracy of a measurement. [ 4 marks ]

Frequent Mistakes
Student Answers:
Accuracy is evaluated based on how close a quantity's measured value is to its actual value. Accuracy is influenced by the level of error present in the measurement. The presence of error will cause a measured value to deviate from its actual value, thus reducing the accuracy level of measurement. The errors that normally reduce the accuracy of a measurement are parallax error and zero error.

Comments:
Identify the command word "state" and the objective of the question, which focuses on "the factors that influence accuracy". Since the allocation of marks is four, the answer should consist of four main points. The student's lengthy explanation about errors and how they reduce the accuracy of a measurement is not required. It shows that the student does not understand the objective of the question clearly and accurately. Though the answer is full of factual information, it is low quality as it fails to meet the objective of the question.

Correct Answer
Any four of the following:
  • The selection of the techniques of measurement.
  • Precision of a device.
  • Sensitivity of a device.
  • The selection of a suitable device based on the size of measurement.
  • The presence of error in a device, or due to the experimenter, during a measurement.

[Biology SPM] Exam Pointers III

Source: Maths & Science Guide

Revision
When answering structural and essay questions in Biology Paper 2, use clear and accurate Biology terms and phrases, in concise and simple sentences that are arranged sequentially.

Structural questions usually consist of several parts dealing with concepts, phenomena, processes and structures. These parts are related to each other and arranged in order of difficulty, from simple identification or recalling of facts to elaboration of points.

A question with many parts may require students to give a definition or meaning, a description of structures and processes, and an explanation of more complex concept.

The allocation of marks for each part can be used to guide students on the length and depth of answers required. For every one mark allocated, one main point should be provided.

Structural questions on the definition or meaning of certain processes or phenomena are often asked.
Eg: Define mitosis. [ 1 mark ]

Correct Answers
A type of nuclear division that results in one parent nucleus producing two genetically identical daughter nuclei with the same chromosome number and type as the parent cell.
  • Comments:
    Mitosis is a nuclear division. Note that Biology terms and phrases such as "parent nucleus" and "daughter nuclei" should be used. Include the fact that the daughter cells are genetically identical to each other and the parent cell. Also, state the chromosome number, which is important in describing mitosis accurately.

Saturday, November 14, 2009

Movie 2012

2012 is a 2009 action film-disaster film based loosely on the 2012 phenomenon and directed by Roland Emmerich. The film has an ensemble cast, including John Cusack, Amanda Peet, Danny Glover, Thandie Newton, Oliver Platt, Chiwetel Ejiofor, and Woody Harrelson. The film was distributed by Columbia Pictures. Filming began in August 2008 in Vancouver. The film is set in a modern setting and only brushes on Mayanism and the Mesoamerican Long Count calendar.

In 2009, a huge solar flare erupts on the sun. One of the protagonists, Adrian Helmsley (Chiwetel Ejiofor), an American scientist, travels to a copper mine in India to meet his friend. His friend has discovered that Earth's core temperature is increasing rapidly. Adrian returns to Washington D.C. and submits a report to his supervisor, who immediately takes him to see Thomas Wilson (Danny Glover), the 45th President of the United States. In 2010, Wilson tells other heads of state the situation at the year's G8 summit and billionaires all over the world buy plane tickets for untold sums of money. In 2011 the original version of the Mona Lisa at the Louvre in Paris is replaced with a decoy, and is sealed away for unknown reasons.

The story jumps ahead to 2012, to Jackson Curtis (John Cusack), a divorced father who works as a limousine driver and writer, and his ex-wife, Kate (Amanda Peet), and children, Noah (Liam James) and Lily (Morgan Lily), who live with Kate's new boyfriend, Gordon (Thomas McCarthy). Jackson takes his children on a camping trip to Yellowstone, where he meets Charlie Frost (Woody Harrelson), who hosts a radio segment that addresses the Mayans' prediction.

Enormous cracks soon develop along the San Andreas Fault, California, and disruptive shaking occurs in the San Francisco Bay area, nearly knocking over a cruise ship. Despite government assurances that all is fine, Jackson grows suspicious.

After hiring a private plane, he drives to Kate's home to save his family and Gordon from the impending earthquakes of the Earth's crust displacement. Jackson quickly collects his family, and Gordon pilots a plane out of the city. Los Angeles then collapses into the Pacific Ocean. When the plane runs low on fuel, they are forced to land in Wyoming. Jackson uses the moment to contact Charlie, regarding a map to ships being built in order to save humanity. They return to Yellowstone to find Charlie, only to discover that he has gone to the mountains to watch the approaching catastrophe.

After getting hold of the map they discover that the ships they are searching for are in China. Jackson and his family leave just in time as Yellowstone Caldera erupts.

In order to get to China they convince a Russian billionaire, Yuri Karpov (Zlatko Buric), to allow them aboard his plane. The group eventually boards an Antonov An-225 at McCarran International Airport, as Las Vegas is destroyed by earthquakes and ravaged by the impeding volcanic ash cloud of Yellowstone.

While in the air, the group learns that the plane does not have enough fuel to reach China: they've passed Honolulu, Hawaii, which has been inundated in lava. As they're about to ditch the plane they discover that they are no longer above the ocean: the Earth's crust has shifted thousands of miles and they are heading towards the Himalayas. During a crash landing on a glacier they manage to escape from the plane safely by using one of the luxury vehicles in cargo as a raft, only to be abandoned by Yuri.

The group eventually find their way to the ships with the help of some locals and are smuggled aboard with the help of a Buddhist monk and his brother, a construction worker. Tsunamis begin to engulf the Indian peninsula, and a giant wave eventually reaches the ships, which turn out to be arks constructed to save the heads of state, hand-picked individuals chosen to repopulate the earth and the rich elite, who could afford to buy tickets (which was earlier mentioned that tickets were €1 000 000 000).

Adrian convinces the captains of the arks to let on more people by quoting Jackson's book which he liked, but the gate on the American ark gets jammed and the ark ends up on a crash course for Mount Everest. Jackson fixes the problem with the help of his son and the ark crashes but slows down enough that the damage is minor. When the flood eventually recedes, the captains of the arks decide upon the Cape of Good Hope in South Africa as a suitable place to reestablish humanity. The movie ends with a view of the world showing the dramatically changed African continent.

*******

Director Roland Emmerich and composer-producer Harald Kloser co-wrote a spec script titled 2012, which was marketed to major studios in February 2008. Nearly all studios met with Emmerich and his representatives to hear the director's budget projection and story plans, a process that the director had previously gone through with the films Independence Day (1996) and The Day After Tomorrow (2004). The film was shopped around with a production budget of $260 million. Later that month, Sony Pictures Entertainment won the rights for the spec script, planning to distribute it under Columbia Pictures. The studio planned to make the film for less than the estimated budget.

Filming was originally scheduled to begin in Los Angeles, California, in July 2008, but instead commenced in Vancouver in August 2008 and concluded in January 2009. Due to the possible 2008 Screen Actors Guild strike, filmmakers set up a contingency plan for salvaging the film. Uncharted Territory, Digital Domain, Double Negative, Scanline, Sony Pictures Imageworks and others were hired to create visual effects for 2012. Thomas Wander co-wrote the score with Harald Kloser.

Although the film depicts the destruction of several major cultural and historical icons around the world, Emmerich stated that the Kaaba was also considered for selection. Kloser had reservations over including Mecca, saying he did not want a fatwā issued against him.

Wednesday, November 11, 2009

[Biology Form 4] Breathing Under Water

The gills in fish help them to breathe while they get their supply of oxygen from the water that surrounds them. Gills have structures called filaments, which are made up of many thin-walled structures called lamellae. Blood capillaries are found close to the surface of these lamellae, and this is where gaseous exchange occurs.
  1. It is this type of blood vessel that is found in a dense network on the gill filaments of a fish.
    • Capillary.

  2. In each body cell of the fish, this aerobic process is what helps synthesise the ATP.
    • Respiration.

  3. The thin-walled structures found in filaments (plural).
    • Lamellae.

  4. The name given to the respiratory structures of a fish (plural).
    • Gills.

  5. The structure that covers and protects the gills.
    • Operculum.

  6. This is one of the characteristics of any respiratory surface where gaseous exchange takes place.
    • Thin.

  7. Each gill is composed of this (singular).
    • Filament.

  8. The all-important gas without which no fish can survive.
    • Oxygen.

Tuesday, November 10, 2009

Acid Attack Schoolgirl To Skip SPM This Year

The Star

GEORGE TOWN: The Form Five schoolgirl whose eyesight was affected after her face was splashed with acid will not be taking the SPM examination this year after all.

Tan Hui Linn, 17, who had earliest stated her intention of sitting for the examination this year, is applying to postpone her sitting to next year.

Her brother, Jun Hong, said she told him that she wanted to wait for her eyes to recover so she could make an all-out effort to study and prepare herself for the SPM next year.

“She said she wanted to focus on getting her eyes treated first and has promised to listen to the doctor’s orders,” he said Monday.

Jun Hong, a Universiti Utara Malaysia student, said his sister was now applying cream to her face so her wound could heal faster.

Hui Linn, who has been moved from the intensive care unit to a normal ward at the Sungai Buloh Hospital in Selangor, still has her right arm and leg wrapped in bandages while the burnt skin on her face has started to peel off.

She was transferred from the Penang Hospital to the Sungai Buloh Hospital on Oct 31.

Asked what was the first thing she would do once she was out of the hospital, Jun Hong said his sister wanted to have a good meal as she was sick of hospital food.

“Her classmates call her up and chat with her sometimes, keeping her informed on the latest gossips in school while she keeps them updated on her recovery,” he said.

Jun Hong said doctors had placed a special lens into Tan’s left eye to repair her cornea, adding that the lens had to be replaced weekly.

“My aunts are taking turns to take care of her,” he added.

Hui Linn and her mother, Chong Swee Lin, 50, were sleeping in their Jalan Tan Sri Teh Ewe Lim home here at 3am on Oct 24 when her 53-year-old father allegedly came in and splashed acid on them. Chong, who was badly burnt, died about 10 hours later.

Hui Linn sustained 60% burns on her face and upper torso. Her father has since been charged with murdering Chong and causing grievous hurt to her.

[Physics Form 4] Curved Mirrors

  1. The two types of curved mirrors are the concave mirror and the convex mirror.

  2. Terminologies associated with concave and convex mirrors:
    • The pole is the centre point of the surface of the concave or convex mirror. It is symbolised as P.

    • The centre of curvature is the centre of sphere in which the concave and convex mirrors are part of. It is symbolised as C.

    • The radius of curvature is the distance from the pole to the centre of curvature. It is symbolsed as R.

    • The principal focus point is the point in which all rays parallel to the principal axis pass through (for concave mirror) or appear to emerge from (for convex mirror), after being reflected from the respective mirrors. It is located on the principal axis and is symbolised as F.

    • The focus point of a concave mirror is real, while the focus point of a convex mirror is virtual.

    • The focal length is the distance between the pole and the focus point. It is symbolised as f. The focal length is half the radius of curvature; f = R/2.

    • The focal length f a concave mirror is real, and denoted as +f, while that of a convex mirror is virtual, and denoted as -f.

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