7. Mitochondria, Cytoskeleton & Nucleus Explained

Mitochondria, the cytoskeleton and the nucleus explained in animation: cristae and the matrix, ATP, mitochondrial DNA and maternal inheritance, heteroplasmy, actin microfilaments, intermediate filaments and microtubules, the nuclear envelope and nuclear pores, chromatin and chromosomes, and the nucleolus. Episode 3 of Chapter 2 of our Physiology course: • Mitochondria: from fewer than 100 to several thousand per cell; globes and rods • Structure: outer membrane with porins, inner membrane folded into cristae, oxidative enzymes, the matrix; ATP • Self-replication, mitochondrial DNA (37 genes), exercise training, maternal inheritance • Mitochondrial disorders: heteroplasmy, ~1300 nuclear genes, onset from childhood to adult life • The cytoskeleton: actin microfilaments (~7 nm, ectoplasm, actin–myosin contraction), intermediate filaments (8–12 nm; desmin, neurofilaments, keratins), microtubules (~25 nm, tubulin; cilia, centrioles, mitotic spindle) • What the cytoskeleton does: cell division, movement, tracks for organelle transport • The nucleus: genes, proteins, replication and mitosis; chromatin and chromosomes • The nuclear envelope: two membranes continuous with the ER; nuclear pores (~9 nm), molecules up to ~44,000 MW, receptor-mediated transport • Nucleoli and the formation of ribosomes ⏱️ Chapters 0:00 The heart cell and the fat cell 1:06 Mitochondria: the power stations 1:46 Inside a mitochondrion: cristae, matrix and ATP 2:43 Mitochondrial DNA and maternal inheritance 3:38 Mitochondrial disorders and heteroplasmy 4:21 The cytoskeleton: microfilaments, intermediate filaments, microtubules 5:44 Functions of the cytoskeleton 6:09 The nucleus: the control centre 7:04 The nuclear envelope and nuclear pores 7:48 Nucleoli and the formation of ribosomes 8:28 Summary 9:00 Next: Eat, Digest, Rebuild 💬 Join the Cascade WhatsApp channel: https://whatsapp.com/channel/0029VbC8... 🎨 Image credits (Noun Project, CC BY 3.0) Heart by Cuputo #Physiology #Mitochondria #Cytoskeleton #Nucleus #GuytonPhysiology #MedicalPhysiology #MBBS #Cascade