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Wednesday, 31 March 2021

Physics Special - Understanding Potential Difference and Electromotive Force

 1. Ini ialah beza keupayaan = tenaga diperlukan utk gerakkan 1C cas antara 2 titik konduktor

This is potential difference = energy required to move 1C of charges between 2 points of conductor:


2. Ini ialah daya gerak elektrik (dge) = tenaga diperlukan utk gerakkan 1C cas dalam litar lengkap (litar konduktor + litar sel kering)

This is electromotive force (emf) = energy required to move 1C of charges in a complete circuit (conductor circuit + dry cell circuit)


3. Maka, kita boleh anggap bahawa beza keupayaan adalah sebahagian drpd dge.
So, we can safely assume that potential difference is a part of emf.

One Love, CH

Saturday, 27 March 2021

Bicara Hujung Minggu - Homo sapiens to Homo economicus

They are no longer interested in genuinely helping others

They are only interested in getting your money.



One Love, CY

Friday, 26 March 2021

Page 153 - Another Textbook Viral In-Waiting?

1. While updating my book for 2021 version, I came across these points from the textbook:

2. It shows that human has the same ancestor as other animals. We can see this from the human phylogenetic tree - human being shares a common ancestor with chimpanzee around 5 million years ago:

3. Going back to dinosaur era, all mammals - from small mice to large whale, including humans - share this common ancestor:


4. I'm already familiar with this concept, but I never expect this to be taught in Malaysian secondary schools. Even in United States high schools, this topic is subject to intense discussion between the creationists and evolutionists.

This is really going to be an interesting one... maybe becomes viral the like Sejarah textbook?

I know it's a mere hypothesis. But, the very presence of this concept approves its credibility.

Darwin will be so proud :-)

One Love

Thursday, 25 March 2021

Exprez Notez - Explaining Root Pressure in 3 Simple Sequences

Let's revise the process of root pressure in the plant's root!
Jom tengok proses tekanan akar dalam akar tumbuhan

*Teachers may download this diagram & show the sequence via PowerPoint
*Cikgu boleh muat turun rajah & tunjukkan urutan menerusi PowerPoint


1. Salt ions are actively pumped into the root hair cell (RHC) vacuoles
Ion garam dipam secara aktif ke dalam vakuol sel akar rambut (SAR)



2. This will cause the vacuole to have low water potential. Water starts to diffuse from soil into RHC
Ini menyebabkan vakuol mempunyai keupayaan air yg rendah (pekat). Air mula meresap masuk dari tanah ke SAR



3. This will cause RHC to have high water potential. Like a dam, water diffuses from RHC through cortex, endodermis, pericycle (CEP) and finally into the xylem
Ini menyebabkan SAR mempunyai keupayaan air yg tinggi (cair). Spt empangan, air meresap dari SAR ke korteks, endodermis, perisikel (KEP) dan akhirnya masuk ke xilem



P/S: Looking forward to share more notes for new syllabus 2021! :-)

One Love, CH

Sunday, 14 February 2021

Jom Diskus Soalan Trial 2020 MRSM - Use of Microbes in Medicinal Products



FOCUS: This question is about the microorganism involved, not the application.
FOKUS: Soalan ini berkenaan mikroorganisma yg terlibat, bukan tentang aplikasi.


1. Since the question asked 4 applications, we can split the answers into 3 marks for each application: 3+3+3+3= 12 marks (max 10)

Memandangkan soalan bertanyakan 4 aplikasi, kita boleh asingkan jawapan kepada 3 markah setiap satu: 3+3+3+3= 12 markah (maksimum 10)


2. Answer/ jawapan:

Application 1: vaccine/ aplikasi 1: vaksin


- Vaccine is made from dead/ weak pathogen/ vaksin diperbuat daripada patogen mati/ lemah
- Pathogen is injected before infection/ patogen disuntik sebelum jangkitan berlaku
- Pathogen stimulates body to produce antibody/ patogen rangsang tubuh utk hasilkan antibodi


Application 2: antibiotic/ aplikasi 2: antibiotik


- Penicillium fungus produces penicillin antibiotic / kulat Penicillium hasilkan antibiotik penisilin
- This fungus is produced in the laboratory/ kulat ini dibiakkan di dalam makmal
- Antibiotic is used to kill pathogens/ antibiotik digunakan utk bunuh patogen


Application 3: antiserum/ aplikasi 3: antiserum


- Specific pathogen is injected into animal/ patogen khusus disuntik ke dalam haiwan
- Body will produce matching antibody/ tubuh akan hasilkan antibodi sepadan
- Antibody is extracted as antiserum/ antibodi diekstrak sebagai antiserum


Application 4: insulin/ aplikasi 4: insulin


- DNA from human pancreatic cell is spliced/ DNA drpd sel pankreas manusia dipotong
- DNA is inserted into bacteria plasmid/ DNA disisipkan ke dalam plasmid bakteria
- Bacteria now can produce human insulin/ bakteria kini boleh hasilkan insulin manusia


One Love, CH