GCSE›Edexcel GCSE Biology›Mind mapsCell StructureEdexcel GCSE Biology: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsOrganellesNucleus holds DNA and controls the cellMitochondria = site of aerobic respirationRibosomes = site of protein synthesisCell membrane controls what enters and leavesPlant extrasCell wall made of cellulose, gives strengthChloroplasts contain chlorophyll for photosynthesisPermanent vacuole holds cell sap, keeps cell turgidBacteriaProkaryotic: no nucleus, no membrane-bound organellesChromosomal DNA = single loop in cytoplasmPlasmid DNA = small extra circular loopsFlagellum rotates to move the cellCell structureeukaryotes and bacteriaSpecialised cellsSperm: acrosome digests egg membraneSperm: haploid nucleus, many mitochondria, tailEgg: nutrients in cytoplasm feed embryoEgg: membrane changes to block extra spermCiliated cells: cilia move mucus awayMicroscopyElectron microscopes: higher magnification and resolutionResolution = ability to separate two close pointsmagnification=image sizeactual size\text{magnification} = \frac{\text{image size}}{\text{actual size}}magnification=actual sizeimage sizeTotal = eyepiece × objective magnificationConvert units first: mm to μm is ×1000Exam tipsLink structure to function in every answerPlant cells do have mitochondriaScientific drawings: no shading, single clear linesDo not confuse plasmid with chromosomal DNA