cytoskeleton | Cell and subcellular organelle | Chapter 3: F.Sc. 1st Year Biology | Lec#31

#Cytoskeleton #CellBiology #FScBiology #1stYearBiology #Chapter3Biology #Microfilaments #Microtubules #IntermediateFilaments #CellStructure #CellOrganelles #BiologyLecture #PTB2025 #PunjabTextBook2025 #NationalCurriculum2025 #BiologyClass11 #ScienceLecture #YouTubeBiology #NEWEducationSystem #ActinProtein #TubulinProtein #Vimentin #Keratin #CellDivision #CellMovement #SpindleFibres #CellShape #CytoskeletonFunction #BiologyInUrdu #BiologyExplained #BiologyLectureUrdu #PakistaniStudents #EduYouTube #BioWithSir #BoardExamPrep #SmartSyllabus2025 #BiologyTopics #UrduScienceLecture #Myosin #CellRigidity #CiliaAndFlagella #OrganellesTransport #CellComponents #StudyWithMe #ScienceForAll #LearnBiology #BioLectureSeries #CellularBiology #UrduMediumBiology #1stYearPrep #BoardExamTips #ScienceEducationPK #BioFacts #FutureDoctors #ScienceIsFun #PTBBiology #MicrofilamentsFunction #TubulinTypes #CytoplasmFibers #UrduBiologyLecture #NEwBookBiology #ChapterWiseLecture #PakistanBiology #BiologyForBeginners #EduSupportPK #CytoskeletonLecture #NewSyllabusBiology #Class11BiologyLecture #HighSchoolBiology #ScienceLearning #CellTheory #NucleusAnchor #CellTransportSystem #BiologyConcepts #BioLecture2025 #BiologyReview #BiologyMCQs #BiologyPastPapers #ExamFocusedLecture #NewBiologyBook2025 #NEwPTBSyllabus #YouTubeScienceLecture #MyosinFunction #UrduBioLecture #PakistaniBiologyChannel #BiologyForMatric #FScScienceTips #ScienceBoardPrep #CellBiologyTopics #SpindleFormation #FilamentTypes #LearnWithFun #Biology2025 #NewSyllabus2025 #MicrotubulesFunction #EducationalVideoPK #IntermediateBioLecture #BioWithExamples #BioWithAnimation #BioCompleteLecture 12- Cytoskeleton It is a network of protein fibres present in cytoplasm. It includes the following types of fibres: 1. Microfilaments: These are present in all eukaryotic cells. Composition. Microfilaments are solid rods made of a globular protein, called actin. Functions.  Cell Movements. Microfilaments disassemble and reassemble and help the cells to change shape and move.  Cell division. Microfilaments also enable a dividing cell to pinch off into two cells.  Cellular contraction. In association with myosin, microfilaments help in cellular contraction. 2. Microtubules: These straight, hollow cylinders are composed of subunits. Composition. Each subunit is made of two different tubulin proteins known as alpha-tubulin and beta-tubulin. Functions.  Microtubules give structure and shape to a cell.  They also serve as highways for the transport of organelles.  Microtubules are the major components of cilia and flagella,  Participate in the formation of spindle fibres during cell division. 3. Intermediate filaments: These are found only in some higher animal groups. Composition. They are made of different proteins but the most common type of protein subunit is vimentin. Some cells may have intermediate filaments made of other proteins. For example, skin cells contain a protein keratin. Functions. Intermediate filaments maintain cell shape and rigidity, and serve to anchor several organelles, including the nucleus.