Cellular Organelles
Class 11 · Biotechnology
4 ideas in Class 11 Biotechnology, explained in plain words, with games and quizzes to practise.
Membranes and Transport
Part of: Gate and Walls
Singer-Nicolson 1972 wraps cells in fluid lipid bilayers with surface and buried proteins; red-cell membranes hold 52 per cent protein and 40 per cent lipid. Molecules diffuse, ride carriers and channels, or pump against gradients using ATP, paired as symport, antiport or uniport.
Why it matters. Model parts plus direction logic answers transport questions.
Key words
- Fluid mosaic model
- : Proteins floating in lipids.
- Peripheral protein
- : Surface signalling protein.
- Integral protein
- : Buried membrane protein.
- Facilitated movement
- : Carrier-aided downhill passage.
- Active transport
- : Energy-driven uphill pumping.
- Symport
- : Two molecules, same direction.
- Antiport
- : Two molecules, opposite directions.
Try it in two minutes
- Float proteins in lipids.
- Split passive from active.
- Pair two-molecule moves.
Try at home. Explain why glucose needs a carrier.
Inner Post
Part of: Gate and Walls
Bacterial peptidoglycan walls differ Gram-thick from Gram-thin while plants use cellulose and fungi chitin, glued by calcium-pectate middle lamella. Rough ER builds proteins, smooth ER builds lipids, Golgi receives at cis and ships at trans, lysosomes digest acidly and central vacuoles store under tonoplast.
Why it matters. Wall chemistry plus pipeline order answers structure questions.
Key words
- Peptidoglycan
- : Bacterial wall mesh.
- Glycocalyx
- : Sticky protective coat.
- Middle lamella
- : Cell-gluing pectate layer.
- Rough ER
- : Ribosome-studded protein builder.
- Golgi apparatus
- : Packing and shipping stack.
- Tonoplast
- : Vacuole-covering membrane.
- Autophagy
- : Self-material recycling.
Try it in two minutes
- Thicken or thin walls.
- Rough builds, smooth lipids.
- Receive cis, ship trans.
Try at home. Explain why antibiotics spare human cells.
Energy Organelles and Ribosomes
Part of: Powerhouses
Cristae-folded mitochondria burn fuel into ATP using own DNA and 70S ribosomes hinting bacterial ancestry, while grana-stacked chloroplasts catch light with thylakoid machinery. Chromo, leuco and chloro plastids colour or store, and 70S pairs 50 with 30 while 80S pairs 60 with 40 across millions per cell.
Why it matters. Fold-function links plus Svedberg pairs answer organelle questions.
Key words
- Cristae
- : Inner membrane folds.
- Matrix
- : Inner mitochondrial compartment.
- Grana
- : Thylakoid coin stacks.
- Stroma
- : Chloroplast fluid space.
- Chromoplast
- : Coloured pigment plastid.
- Leucoplast
- : Colourless storage plastid.
- Ribozyme
- : Catalytic ribosomal RNA.
Try it in two minutes
- Fold cristae for area.
- Stack grana for light.
- Pair ribosome subunits.
Try at home. Explain why muscle cells pack mitochondria.
Skeleton, Movers, Nucleus and Chromosomes
Part of: Control Room
Tubulin microtubules 25 nm, actin 6 nm and intermediates 10 nm brace cells while 9-plus-2 cilia sweep and flagella whip, centriole triplets seed spindles. Pored envelopes guard nucleoli making rRNA, and humans corrected 48 to 46 chromosomes with dogs at 78 and goldfish at 100.
Why it matters. Size order plus count facts answers final questions.
Key words
- Microtubule
- : 25 nm tubulin tube.
- Axoneme
- : 9-plus-2 mover core.
- Centriole
- : Nine-triplet spindle seeder.
- Nucleolus
- : rRNA-making nuclear body.
- Autosome
- : Body chromosome.
- Allosome
- : Male-female chromosome.
Try it in two minutes
- Size 25, 6, 10.
- Count 9-plus-2.
- Correct 48 to 46.
Try at home. Explain why wheat breaks diploid rules.
What your child will practise
- Energy Organelles and Ribosomes: Desert Puzzle (Clue Puzzle)
- Energy Organelles and Ribosomes: Desert Quick Fire (Quick Fire)
- Inner Post: Space Puzzle (Clue Puzzle)
- Membranes and Transport: Candy Quest (Flip and Match)
- Skeleton, Movers, Nucleus and Chromosomes: Jungle Quick Fire (Quick Fire)
- Quiz: Energy Organelles and Ribosomes (8 questions)
- Quiz: Inner Post (8 questions)
- Quiz: Membranes and Transport (8 questions)
- Quiz: Skeleton, Movers, Nucleus and Chromosomes (8 questions)