[Biology Form 4] How to Synthesis Extracellular Protein?

  • Extracellular protein is the protein that is destined for export from a cell such as digestive enzyme that is made by pancreas cell.

  • The organelles that involved in the process are nucleus, ribosome, RER,Golgi apparatus and mitochondria.

  • Flow chart shows how the internal membrane system of a cell packages a protein for export.

  • 1. Instructions for making protein are transcribed from DNA by RNA in the nucleus.
    2. RNA leaves the nucleus through nuclear pore and proceeds to a ribosome located on the RER.

    3. Ribosome synthesis the correct sequence of amino acids for synthesizing that particular protein as instructed.

    4. When protein synthesis is complete, the protein travels through the RER and is then encapsulated in a transport vesicle.

    5. The transport vesicle fuses with a Golgi apparatus, releasing the protein.

    6. In the Golgi apparatusthe protein is further modified and is then shunted to the ends of Golgi apparatus or cisternae. There, the protein waits for a secretory vesicle.

    7. The secretory vesicle will carry the protein to the plasma membrane of the cell and fuses with it. Then, the protein is released outside the cell.


    [Biology Form 4] Enzyme

    1. Structure: What chemical compound is an enzyme made up of? 

    2. Function: What is the role played by enzymes in living organisms?
    Enzymes speed up the rate of chemical reactions in living organisms.

    3. State the characteristics of enzymes:
    a) Enzymes are made up of proteins.
    b) They are catalysts that speed up the rate of a reaction.

    c) They are not destroyed / altered by the reactions they catalyse.

    d) Enzymes have specific active sites where they bind with substrates.

    e) Enzymes show substrate specificity - they can only bind with specific substrates.

    f) Enzymes are needed only in small amounts.

    g) Enzyme-catalysed reactions are reversible - they catalyse reactions in either direction.

    h) The activity of enzymes can be slowed down by inhibitors.

    i) Enzymes work more effectively with the help of co-factors.

    j) Enzymes are affected by factors such as temperaturepHsubstrate concentration and enzyme concentration.

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

    5. Where are enzymes synthesised in a cell?
    In ribosomes.

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

    7. Example: State an example of enzymes involved in the digestion or hydrolysis of each of the following substrates:
    a) StarchAmylase
    b) ProteinsPepsin
    c) FatsLipase
    d) MaltoseMaltase
    e) LactoseLactase
    f) SucroseSucrase
    g) CelluloseCellulase

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

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

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


    [Biology Form 4] Animal Cell & Plant Cell

    • The cell is the basic unit of all organism. It is made up of a cell membrane that encloses the cytoplasm.
    • Contained within the cytoplasm are not only the nucleus but also organelles, whose specific functions help the cell perform a range of activities.
    • While plant and animal cells are similar, the plant cell has, in addition to the cell membrane, another boundary that separates it from its external environment. This is called the cell wall.
    • As most plant cells carry out photosynthesis - the synthesis of organic substances - they contain chloroplasts.
    • In plant cells, vacuoles also tend to be larger in size and smaller in number than those found in animal cells.
                                                                       Typical Plant Cell :

    Typical Animal Cell :

    In the laboratory, you have learned how to prepare a microscope slide of human cheek cells as well as the epidermal cells of onions.

    a) The differences you can observe between the two types of cells in term of the following:
    • Shape                                                                                                                     Onion cells have a regular shape while cheek cells have an irregular shape.
    • Presence or absence of cell wall                                                                           Onion cells have a cell wall while cheek cells do not.                                                                                               
    • Presence or absence of vacuoles                                                                          Onion cells have a large vacuole while vacuoles in cheek cells, if present, are small.                                                                                    
    b) Can you observe chloroplasts in the epidermal cells of onions? Explain your answer.                                
                                                                                                                                              => No chloroplasts can be observed in the epidermal cells of onions because epidermal cells do not carry out photosynthesis.



    a) Statement of the problem: It always must be a question and ended with question mark. Read the question well and you will find it in the hint in the question. Start your statement of the problem with ‘How does manipulated variable affect responding variable?’ or ‘Does increasing/decreasing manipulated variable increase/decrease the responding variable?
    b) Aim of experiment: It always must be a statement and ended with full stop. Start your aim of experiment with ‘To compare … / To investigate … / To study …
    c) All the variables: List out all the variables and separate each variable in the following sequence.
    • Manipulated variable: (axis-x values)
    • Responding variable: (axis-y values)
    • Constant variable:
    d) Statement of the hypothesis: It always must be a statement and ended with full stop. ‘The manipulated variable, the higher/lower/increase/decrease responding variable
    Important note: Must follow the sequence (always start with manipulated variable and follow by responding variable).
    e) List of substances and apparatus: Always separate substance and apparatus even though this is in one section. Must list everything completely to get 3 marks!
    Substances: (the same meaning with materials in PEKA experiments)
    Important note: Solution: try to give the concentration of the solution (always in the range of 0.1 – 1.0 mol dm-3) and concentrated solution (>1.0 mol dm-3)
    • 0.1 mol dm-3 of hydrochloric acid
    • 0.5 mol dm-3 of nitric acid
    • 1.0 mol dm-3 copper(II) suphate solution
    • 0.5 mol dm-3 NaOH, zinc powder
    Apparatus: try to list as complete as possible (everything that can be reused in the experiment)
    • Stop watch
    • measuring cylinder
    • beaker
    • retort stand
    • conical flask
    • filter funnel
    • trough
    • forceps
    • tongs …
    f) Procedure of the experiment: This is the hardest part to get full marks (3 marks). You need to write the procedure as complete as possible which means all steps are to be written in detail. Berry Teacher would recommend the sentence should be written in passive form sentence (same in PEKA) and it can be present or past tense (no penalty). And try to uniform it. From the previous SPM Paper 3 record, there is no penalty if you write in active form sentence but not in PEKA report!
    g) Tabulation of data: This is the easiest part to get one mark, as long as you draw a table (empty table / box), you will be given at least one mark. Remember to write unit in the manipulated variable column and responding variable column


    Pemarkahan Kertas 3

    1)inference (1mark)
    2)hypothesis (1mark)
    3)Aim (1mark)
    4)MANIPULATED+RESPONDING  variables (1mark)
    5)FIXED variable (1mark)
    6)COMPLETE list of apparatus and materials (1mark)
    7)functional diagram of apparatus (1mark)
    8)State how the manipulated variable is controlled (1mark)
    9)State how the responding variable is measured (1mark)
    10)State how the procedure is repeated to obtain at least 5 sets of results (1mark)
    11)State how the data is tabulated (1mark)
    12)State how the data is analysed (1mark)
    TOTAL MARKS =12marks

    Example Question
    In the ocean, the water is often more calm. As the waves move towards the beach they become more distinct as shown by diagram 4.1. Study the shape and wave length shown in diagram 4.1.

    Based on the information and the observation above:

    (a)State one suitable inference
    (manipulated) AFFECTS (responding)
    depth AFFECTS wavelength   √

    b)State one suitable hypothesis
    (manipulated) increase, (responding)increase
    (manipulated) derease, (responding)decrease
    (manipulated) increase, (responding)decrease (and vice versa)

    Depth increases, wavelength increases  √

    (c)With the use of apparatus such as ripple tank, stroboscope and other suitable apparatus, describe an experiment framework to investigate the hypothesis stated in 4(b). In your description, state clearly the following :

    (i) Aim of the experiment
    you can take fron the question.For example :
    In the ocean, the water is often more calm. As the waves move towards the beach they become more distinct as shown by diagram 4.1. Study the shape and wave length shown in diagram 4.1.
    (ocean is more depth, beach is less depth. the question ask you to study wavelength also) 
    To INVESTIGATE the RELAITIONSHIP between(manipulated) and (responding)
    Answer :
    To investigate the relationship between depth and wavelength  √

    (ii) Variables in the experiment
    Manipulated variable : depth, h
    Responding variable : wavelength, λ  √
    fixed variable: frequency  √

    (iii) List of apparatus and materials.
    D.c. power supply, ripple tank and accessories, lamp, metre rule, white paper, 5 pieces of perspecs/glass, stroboscope  √

    (iv) Arrangement of the apparatus  √
    Draw a functional diagram, use a ruler and pencil for this question.

    (iv) The procedure of the experiment which includes the method of controlling the manipulated variable and the method of measuring the responding variable.
    State how the manipulated variable is controlled
    The current was switched on.
    The put one piece of perspecs in the ripple tank
    State how the responding variable is measured
    Mark the position of wave on the white paper as seen through the stroboscope
    Measure the wavelength using metre rule
    The procedure was repeated for different depth by putting pieces of perspecs on top of the previous perspecs in the ripple tank 2,3,4 and 5 number of perspecs.  √

    (v) The way you would tabulate the data
    (manipulated variables)(responding variables)

    don`t forget to put unit.For example:  √
    number of perspecsWavelength / cm

    (vi) The way you would analyse the data.
    must draw graph but draw x-axis and y-axis
    x-axis label manipulated variables
    y-axis label responding varialbes  


    1. Kertas 1 (objektif) – 40 markah
    - 1 soalan – 1 markah
    - Masa – 1 jam
    - 1 bab – 2/3 soalan 
    - Cari jawapan salah dulu
    - Pilih satu jawapan sahaja
    - Buat ulangkaji / latih tubi berdasarkan topik
    - Baca dua kali sebelum menjawab
    - Urus masa dengan baik

    2. Cara menjawab kertas 2

    a) Soalan struktur (40 markah)
    - Ada 4 soalan – 10 markah 1 soalan
    - Masa 30/40 minit
    - Ada pecahan i) ii) iii) iv)
    - Baca tokoh / peristiwa / ciri-ciri / konsep/ istilah / faktor / kesan
    - Meliputi teks T4/T5
    - Jawab dalam bentuk ayat

    b) Soalan esei
    - Baca dan garis perkataan / kunci kata dalam soalan 
    - Jawab 3 soalan sahaja (60 markah)
    - Bentuk ayat ringkas dan padat
    - Beri 1 contoh sahaja dalam isimesti ada huraian 
    - Panjang jawapan berdasarkan markah soalan 
    - 1 soalan – 20 markah – guna masa 30 minit sahaja
    - Merangkumi teks T4 / T5
    - Jika 10 markah tulis 5 isi (1 isi - 2 markah)
    - Jika 5 markah tulis 3 isi atau 1 perenggan
    - 1 isi tulis dalam satu perenggan
    - Tiada pengenalan atau penutup 
    - Tulis isi dan huraian sahaja

    C Cadangan kepada calon / guru mata pelajaran Sejarah

    - Beri tumpuan kepada fakta dalam buku teks sebagai rujukan utama
    - Memahami konsep Sejarah
    - Perbanyakkan latihan / kemukakan banyak soalan setiap bab 
    - Kuasai teknik menjawab yang tepat
    - Buat nota / peta minda
    - Buat kumpulan / perbincangan topik



    Petikan membicangkan .........

    Masalah =kekangan/halangan
    Langkah =cara-cara,mekanisme
    Peranan =fungsi,tanggungjawab

    Pendahuluan  *keterangan tempat
                           >di negara kita
                           >di Malaysia
                           >di sekolah-sekolah ini
                           *keterangan masa
                           >pada masa ini
                           >pada zaman ini
                          *keterangan siapa
                           >dalam kalangan murid
                           >dalam kehidupan manusia

    Isi tersurat =tambah penanda wacana sebelum isi yang lain
                        *Selain itu,
                        *Disamping itu,
                        *Tambahan lagi,

    Isi tersirat =cara-cara
                      *kerajaan -kempen
                                      -menguatkuasakan undang-undang

                      *media massa -mengiklankan dokumentari
                                              -memaparkan dokumentari