Form 4 BiologyBiologi Tingkatan 4

Chapter 3: Plasma MembraneBab 3: Pergerakan Bahan Merentasi Membran Plasma

How cells control what enters and exits — the border control of life!Bagaimana sel mengawal apa yang masuk dan keluar — kawalan sempadan kehidupan!

🎯 What You'll Learn🎯 Objektif Pembelajaran

Explain the Fluid Mosaic Model of plasma membraneMenerangkan model mozaik bendalir membran plasma

Compare passive and active transportMembandingkan pengangkutan pasif dan aktif

Describe osmosis and its effects on cellsMenerangkan osmosis dan kesannya ke atas sel

Apply concepts to real-life situationsMengaplikasikan konsep dalam kehidupan harian

🧬 Fluid Mosaic Model🧬 Model Mozaik Bendalir

🔑 KEY CONCEPT:🔑 KONSEP UTAMA: The plasma membrane is a phospholipid bilayer with proteins "floating" in it like a mosaic. "Fluid" because components can move laterally.Membran plasma ialah dwilapisan fosfolipid dengan protein "terapung" di dalamnya seperti mozaik. "Bendalir" kerana komponen boleh bergerak ke tepi.
ComponentKomponenLocationLokasiFunctionFungsi
Phospholipid bilayerDwilapisan fosfolipidMain structureStruktur utamaSelective barrierPenghalang selektif
Channel proteinsProtein saluranEmbeddedTertanamPassive transportPengangkutan pasif
Carrier proteinsProtein pembawaEmbeddedTertanamActive/passive transportPengangkutan aktif/pasif
CholesterolKolesterolBetween phospholipidsAntara fosfolipidMaintains stabilityMengekalkan kestabilan
GlycoproteinsGlikoproteinOuter surfacePermukaan luarCell recognitionPengecaman sel
Phospholipid head Phospholipid tail Integral protein Cholesterol

Fig 1: Fluid Mosaic Model of Plasma MembraneRajah 1: Model Mozaik Bendalir Membran Plasma

📊 Passive vs Active Transport📊 Pengangkutan Pasif vs Aktif

FeatureCiriPassivePasifActiveAktif
Energy required?Tenaga diperlukan?NoTidakYes (ATP)Ya (ATP)
DirectionArahHigh → LowTinggi → RendahLow → HighRendah → Tinggi
ExamplesContohDiffusion, OsmosisResapan, OsmosisNa⁺/K⁺ pumpPam Na⁺/K⁺
Proteins usedProtein digunakanChannelsSaluranCarriers onlyPembawa sahaja
💡 Memory Trick:💡 Trik Ingatan: "PASIF santai, AKTIF kena bayar" — Passive is free (santai), Active needs ATP (payment)"PASIF santai, AKTIF kena bayar" — Pasif = percuma (santai), Aktif = perlu bayaran ATP
Simple Diffusion Osmosis Carrier ATP ADP Pi Active Transport

Fig 2: Types of Transport Across MembraneRajah 2: Jenis Pengangkutan Merentasi Membran

💧 Solutions and Cell Effects💧 Larutan dan Kesan ke atas Sel

SolutionLarutanRBC EffectKesan Sel HaiwanPlant Cell EffectKesan Sel Tumbuhan
HypotonicHipotonikHaemolysis (bursts)Hemolisis (pecah)Turgid (ideal)Turgid (ideal)
IsotonicIsotonikNormalNormalFlaccidFlokid
HypertonicHipertonikCrenation (shrivels)Krenasi (menggecut)PlasmolysisPlasmolisis

Osmosis: Water Movement Across MembranesOsmosis: Pergerakan Air Merentasi Membran

Hypotonic — water ENTERS cell (swelling) Cell H₂O in Low solute Isotonic — balanced Cell Equal Hypertonic — water LEAVES cell (shrinks) Cell H₂O out High solute Cell Solution

Fig X: Osmosis — water moves from dilute to concentratedRajah X: Osmosis — air bergerak dari rendah ke pekat

Diffusion vs Active TransportPengangkutan Pasif vs Aktif

Diffusion High concentration Low concentration ↓ gradient Passive (no energy) Active Transport Low concentration High concentration PUMP ↑ Against gradientRequires ATP

Fig Y: Diffusion vs Active TransportRajah Y: Pengangkutan Pasif vs Aktif

⚡ Quick Check

What happens to a red blood cell in distilled water?Apakah yang berlaku kepada sel darah merah dalam air suling?

AHaemolysis (bursts)Hemolisis (pecah)
BCrenation (shrivels)Krenasi (menggecut)
CNo changeTiada perubahan
DPlasmolysisPlasmolisis

🇲🇾 Malaysian Innovation

Sil-RH Membrane developed by Malaysian researchers uses similar principles for water desalination!Membran Sil-RH dibangunkan oleh penyelidik Malaysia menggunakan prinsip yang sama untuk penyahgaraman air!

📋 SPM Practice📋 Latihan SPM

SPM 2022 Paper 2

A student placed red blood cells in three solutions: A (distilled water), B (0.85% NaCl), C (5% NaCl). Explain what happens in each. [6 marks]Seorang pelajar meletakkan sel darah merah dalam tiga larutan: A (air suling), B (0.85% NaCl), C (5% NaCl). Terangkan apa yang berlaku dalam setiap satu. [6 markah]

📌 Keywords:📌 Kata Kunci: Haemolysis, Crenation, Water potential, OsmosisHemolisis, Krenasi, Potensi air, Osmosis

🃏 Flashcards🃏 Kad Imbas

Haemolysis?Hemolisis?
RBC bursts in hypotonic solutionSel darah merah pecah dalam larutan hipotonik
Crenation?Krenasi?
RBC shrivels in hypertonic solutionSel haiwan menggecut dalam larutan hipertonik
Plasmolysis?Plasmolisis?
Plant cell membrane pulls away from wallMembran sel tumbuhan terpisah daripada dinding
Active transport needs?Pengangkutan aktif perlu?
ATP (energy)ATP (tenaga)
IV drip must be?Cecair IV mesti?
Isotonic with blood (0.85% NaCl)Isotonik dengan darah (0.85% NaCl)