In this video, we're going to begin our introduction to the cytoskeleton. And so the cytoskeleton, as implied by the cyto prefix, is a network of elongated proteins that are found in the cytoplasm of a cell, and the cytoskeleton is going to have multiple different functions. Now also implied by the term cytoskeleton, it has a resemblance to our own skeletons. And so just like our skeletons give our bodies their shape and structure, the cytoskeleton of cells does something similar, and so its functions include providing cell shape, as well as cell structure as well. But once again, we know that the cytoskeleton has multiple different functions. So not only does it provide the cell with its shape and structure, but it's also very important for cell movement, transportation, and bio signaling as well. Now, really there are 3 major components of the cytoskeleton and we've got those 3 major components numbered down below here and those are the microfilaments, the intermediate filaments, and the microtubules. And so the microfilaments are the smallest component of the cytoskeleton. They're the smallest in size and usually, microfilaments are going to be made of thin rods of repeating actin proteins. And so actin is the name of a protein that will repeatedly come together to build microfilaments. Now intermediate filaments, as their name implies, are intermediate in size. And so that means that it's going to be right in the middle. It's going to be larger than microfilaments, but smaller than microtubules. Intermediate filaments turn out that they are made of a lot of different types of proteins, and so they can be made of variable proteins. Now the microtubules, on the other hand, are going to be the largest component of the cytoskeleton. So they are the largest in size. And as their name implies with the tubule here, they are forming these large tubes that are made up of repeating tubulin proteins. And so these tubulin proteins will repeatedly come together to build the microtubules. And so let's take a look at our image down below to get a better idea of this cytoskeleton here. And so notice that we're saying that the cytoskeleton has somewhat of a resemblance to our own skeletons here. And so you can see that through, fluorescence microscopy, we can actually turn components of the cytoskeleton into different colors. Just like you can see here that the skeleton hand here is having different colors. And so notice over here on the far left, we're showing you the microfilaments. And in this image here, you can see that the components of the microfilaments are filled, are colored in red here. And those red, you can see, are filling up the cell, so they're found throughout the cytoplasm of the cell. And also, microfilaments are going to be the smallest in diameter as we indicated up above. So in terms of diameter, this way, they are the smallest in diameter from this end to this end right here. And so next what we have are the intermediate filaments here in the middle, and the intermediate filaments, as we indicated, are intermediate in size, so they're a little bit longer here than the microfilaments, and you can see that they are shown in green here in this image. And then the microtubules, which are the largest in size, they're going to come together to form this large tube that you see over here, and they're also colored in green over here in this image as well. And so what you'll notice is that the cytoskeleton really fills up the entire space of the cytoplasm of a cell. And once again, it plays very very important roles for giving the cell its shape, its structure, providing movement, transportation, and biosignaling. And so this here concludes our introduction to the cytoskeleton and we'll be able to apply these concepts as we move forward in our course. So I'll see you all in our next video.
- 1. Introduction to Microbiology3h 21m
- Introduction to Microbiology16m
- Introduction to Taxonomy26m
- Scientific Naming of Organisms9m
- Members of the Bacterial World10m
- Introduction to Bacteria9m
- Introduction to Archaea10m
- Introduction to Eukarya20m
- Acellular Infectious Agents: Viruses, Viroids & Prions19m
- Importance of Microorganisms20m
- Scientific Method27m
- Experimental Design30m
- 2. Disproving Spontaneous Generation1h 18m
- 3. Chemical Principles of Microbiology3h 38m
- 4. Water1h 28m
- 5. Molecules of Microbiology2h 23m
- 6. Cell Membrane & Transport3h 28m
- Cell Envelope & Biological Membranes12m
- Bacterial & Eukaryotic Cell Membranes8m
- Archaeal Cell Membranes18m
- Types of Membrane Proteins8m
- Concentration Gradients and Diffusion9m
- Introduction to Membrane Transport14m
- Passive vs. Active Transport13m
- Osmosis33m
- Simple and Facilitated Diffusion17m
- Active Transport30m
- ABC Transporters11m
- Group Translocation7m
- Types of Small Molecule Transport Review9m
- Endocytosis and Exocytosis15m
- 7. Prokaryotic Cell Structures & Functions5h 52m
- Prokaryotic & Eukaryotic Cells26m
- Binary Fission11m
- Generation Times16m
- Bacterial Cell Morphology & Arrangements35m
- Overview of Prokaryotic Cell Structure10m
- Introduction to Bacterial Cell Walls26m
- Gram-Positive Cell Walls11m
- Gram-Negative Cell Walls20m
- Gram-Positive vs. Gram-Negative Cell Walls11m
- The Glycocalyx: Capsules & Slime Layers12m
- Introduction to Biofilms6m
- Pili18m
- Fimbriae & Hami7m
- Introduction to Prokaryotic Flagella12m
- Prokaryotic Flagellar Structure18m
- Prokaryotic Flagellar Movement11m
- Proton Motive Force Drives Flagellar Motility5m
- Chemotaxis14m
- Review of Prokaryotic Surface Structures8m
- Prokaryotic Ribosomes16m
- Introduction to Bacterial Plasmids13m
- Cell Inclusions9m
- Endospores16m
- Sporulation5m
- Germination5m
- 8. Eukaryotic Cell Structures & Functions2h 18m
- 9. Microscopes2h 46m
- Introduction to Microscopes8m
- Magnification, Resolution, & Contrast10m
- Introduction to Light Microscopy5m
- Light Microscopy: Bright-Field Microscopes23m
- Light Microscopes that Increase Contrast16m
- Light Microscopes that Detect Fluorescence16m
- Electron Microscopes14m
- Reviewing the Different Types of Microscopes10m
- Introduction to Staining5m
- Simple Staining14m
- Differential Staining6m
- Other Types of Staining11m
- Reviewing the Types of Staining8m
- Gram Stain13m
- 10. Dynamics of Microbial Growth4h 36m
- Biofilms16m
- Growing a Pure Culture5m
- Microbial Growth Curves in a Closed System21m
- Temperature Requirements for Microbial Growth18m
- Oxygen Requirements for Microbial Growth22m
- pH Requirements for Microbial Growth8m
- Osmolarity Factors for Microbial Growth14m
- Reviewing the Environmental Factors of Microbial Growth12m
- Nutritional Factors of Microbial Growth30m
- Growth Factors4m
- Introduction to Cultivating Microbial Growth5m
- Types of Solid Culture Media4m
- Plating Methods16m
- Measuring Growth by Direct Cell Counts9m
- Measuring Growth by Plate Counts14m
- Measuring Growth by Membrane Filtration6m
- Measuring Growth by Biomass15m
- Introduction to the Types of Culture Media5m
- Chemically Defined Media3m
- Complex Media4m
- Selective Media5m
- Differential Media9m
- Reducing Media4m
- Enrichment Media7m
- Reviewing the Types of Culture Media8m
- 11. Controlling Microbial Growth4h 10m
- Introduction to Controlling Microbial Growth29m
- Selecting a Method to Control Microbial Growth44m
- Physical Methods to Control Microbial Growth49m
- Review of Physical Methods to Control Microbial Growth7m
- Chemical Methods to Control Microbial Growth16m
- Chemicals Used to Control Microbial Growth6m
- Liquid Chemicals: Alcohols, Aldehydes, & Biguanides15m
- Liquid Chemicals: Halogens12m
- Liquid Chemicals: Surface-Active Agents17m
- Other Types of Liquid Chemicals14m
- Chemical Gases: Ethylene Oxide, Ozone, & Formaldehyde13m
- Review of Chemicals Used to Control Microbial Growth11m
- Chemical Preservation of Perishable Products10m
- 12. Microbial Metabolism5h 16m
- Introduction to Energy15m
- Laws of Thermodynamics15m
- Chemical Reactions9m
- ATP20m
- Enzymes14m
- Enzyme Activation Energy9m
- Enzyme Binding Factors9m
- Enzyme Inhibition10m
- Introduction to Metabolism8m
- Negative & Positive Feedback7m
- Redox Reactions22m
- Introduction to Aerobic Cellular Respiration25m
- Types of Phosphorylation12m
- Glycolysis19m
- Entner-Doudoroff Pathway11m
- Pentose-Phosphate Pathway10m
- Pyruvate Oxidation8m
- Krebs Cycle16m
- Electron Transport Chain19m
- Chemiosmosis7m
- Review of Aerobic Cellular Respiration19m
- Fermentation & Anaerobic Respiration23m
- 13. Photosynthesis2h 31m
- 14. DNA Replication2h 25m
- 15. Central Dogma & Gene Regulation7h 14m
- Central Dogma7m
- Introduction to Transcription20m
- Steps of Transcription22m
- Transcription Termination in Prokaryotes7m
- Eukaryotic RNA Processing and Splicing20m
- Introduction to Types of RNA9m
- Genetic Code25m
- Introduction to Translation30m
- Steps of Translation23m
- Review of Transcription vs. Translation12m
- Prokaryotic Gene Expression21m
- Review of Prokaryotic vs. Eukaryotic Gene Expression13m
- Introduction to Regulation of Gene Expression13m
- Prokaryotic Gene Regulation via Operons27m
- The Lac Operon21m
- Glucose's Impact on Lac Operon25m
- The Trp Operon20m
- Review of the Lac Operon & Trp Operon11m
- Introduction to Eukaryotic Gene Regulation9m
- Eukaryotic Chromatin Modifications16m
- Eukaryotic Transcriptional Control22m
- Eukaryotic Post-Transcriptional Regulation28m
- Post-Translational Modification6m
- Eukaryotic Post-Translational Regulation13m
- 16. Microbial Genetics4h 44m
- Introduction to Microbial Genetics11m
- Introduction to Mutations20m
- Methods of Inducing Mutations15m
- Prototrophs vs. Auxotrophs13m
- Mutant Detection25m
- The Ames Test14m
- Introduction to DNA Repair5m
- DNA Repair Mechanisms37m
- Horizontal Gene Transfer18m
- Bacterial Transformation11m
- Transduction32m
- Introduction to Conjugation6m
- Conjugation: F Plasmids18m
- Conjugation: Hfr & F' Cells19m
- Genome Variability21m
- CRISPR CAS11m
- 17. Biotechnology3h 0m
- 18. Viruses, Viroids, & Prions4h 56m
- Introduction to Viruses20m
- Introduction to Bacteriophage Infections14m
- Bacteriophage: Lytic Phage Infections12m
- Bacteriophage: Lysogenic Phage Infections17m
- Bacteriophage: Filamentous Phage Infections8m
- Plaque Assays9m
- Introduction to Animal Virus Infections10m
- Animal Viruses: 1. Attachment to the Host Cell7m
- Animal Viruses: 2. Entry & Uncoating in the Host Cell19m
- Animal Viruses: 3. Synthesis & Replication22m
- Animal Viruses: DNA Virus Synthesis & Replication14m
- Animal Viruses: RNA Virus Synthesis & Replication22m
- Animal Viruses: Antigenic Drift vs. Antigenic Shift9m
- Animal Viruses: Reverse-Transcribing Virus Synthesis & Replication9m
- Animal Viruses: 4. Assembly Inside Host Cell8m
- Animal Viruses: 5. Release from Host Cell15m
- Acute vs. Persistent Viral Infections25m
- COVID-19 (SARS-CoV-2)14m
- Plant Viruses12m
- Viroids6m
- Prions13m
- 19. Innate Immunity7h 15m
- Introduction to Immunity8m
- Introduction to Innate Immunity17m
- Introduction to First-Line Defenses5m
- Physical Barriers in First-Line Defenses: Skin13m
- Physical Barriers in First-Line Defenses: Mucous Membrane9m
- First-Line Defenses: Chemical Barriers24m
- First-Line Defenses: Normal Microflora5m
- Introduction to Cells of the Immune System15m
- Cells of the Immune System: Granulocytes29m
- Cells of the Immune System: Agranulocytes25m
- Introduction to Cell Communication5m
- Cell Communication: Surface Receptors & Adhesion Molecules16m
- Cell Communication: Cytokines27m
- Pattern Recognition Receptors (PRRs)45m
- Introduction to the Complement System24m
- Activation Pathways of the Complement System23m
- Effects of the Complement System23m
- Review of the Complement System12m
- Phagoctytosis21m
- Introduction to Inflammation18m
- Steps of the Inflammatory Response26m
- Fever8m
- Interferon Response25m
- 20. Adaptive Immunity7h 14m
- Introduction to Adaptive Immunity32m
- Antigens12m
- Introduction to T Lymphocytes38m
- Major Histocompatibility Complex Molecules20m
- Activation of T Lymphocytes21m
- Functions of T Lymphocytes25m
- Review of Cytotoxic vs Helper T Cells13m
- Introduction to B Lymphocytes27m
- Antibodies14m
- Classes of Antibodies35m
- Outcomes of Antibody Binding to Antigen15m
- T Dependent & T Independent Antigens21m
- Clonal Selection20m
- Antibody Class Switching17m
- Affinity Maturation14m
- Primary and Secondary Response of Adaptive Immunity21m
- Immune Tolerance28m
- Regulatory T Cells10m
- Natural Killer Cells16m
- Review of Adaptive Immunity25m
- 21. Principles of Disease6h 57m
- Symbiotic Relationships12m
- The Human Microbiome46m
- Characteristics of Infectious Disease47m
- Stages of Infectious Disease Progression26m
- Koch's Postulates26m
- Molecular Koch's Postulates11m
- Bacterial Pathogenesis36m
- Introduction to Pathogenic Toxins6m
- Exotoxins Cause Damage to the Host40m
- Endotoxin Causes Damage to the Host13m
- Exotoxins vs. Endotoxin Review13m
- Immune Response Damage to the Host15m
- Introduction to Avoiding Host Defense Mechanisms8m
- 1) Hide Within Host Cells5m
- 2) Avoiding Phagocytosis31m
- 3) Surviving Inside Phagocytic Cells10m
- 4) Avoiding Complement System9m
- 5) Avoiding Antibodies25m
- Viruses Evade the Immune Response27m
Introduction to the Cytoskeleton - Online Tutor, Practice Problems & Exam Prep
Introduction to the Cytoskeleton
Video transcript
Microfilaments are made of repeating subunits of:
Which of the following is NOT a part of the cytoskeletal system of a cell?
Do you want more practice?
Here’s what students ask on this topic:
What are the main functions of the cytoskeleton in a cell?
The cytoskeleton has several crucial functions in a cell. It provides the cell with its shape and structural integrity, much like a skeleton does for the human body. Additionally, the cytoskeleton is essential for cell movement, enabling cells to change shape and migrate. It also plays a vital role in intracellular transport, facilitating the movement of organelles and vesicles within the cell. Furthermore, the cytoskeleton is involved in bio-signaling, helping to transmit signals from the cell membrane to the interior, which is crucial for various cellular processes.
What are the three main components of the cytoskeleton?
The cytoskeleton is composed of three main components: microfilaments, intermediate filaments, and microtubules. Microfilaments are the smallest and are made up of actin proteins. Intermediate filaments are of intermediate size and can be composed of various proteins, providing mechanical support to the cell. Microtubules are the largest components, formed from tubulin proteins, and they play a key role in maintaining cell shape, enabling intracellular transport, and facilitating cell division.
How do microfilaments differ from microtubules in terms of structure and function?
Microfilaments and microtubules differ significantly in both structure and function. Microfilaments are the smallest components of the cytoskeleton, composed of actin proteins arranged in thin rods. They are primarily involved in maintaining cell shape, enabling cell movement, and facilitating muscle contraction. In contrast, microtubules are the largest components, formed from tubulin proteins that create hollow tubes. Microtubules are crucial for maintaining cell shape, providing tracks for intracellular transport, and playing a key role in cell division by forming the mitotic spindle.
What proteins make up microfilaments and microtubules?
Microfilaments are primarily composed of actin proteins. Actin molecules polymerize to form long, thin rods that make up the microfilaments. On the other hand, microtubules are made up of tubulin proteins. Tubulin dimers, consisting of α-tubulin and β-tubulin, polymerize to form the hollow tubes that constitute microtubules. These structural proteins are essential for the various functions that microfilaments and microtubules perform within the cell.
What role do intermediate filaments play in the cytoskeleton?
Intermediate filaments play a crucial role in providing mechanical support and stability to cells. They are of intermediate size compared to microfilaments and microtubules and can be composed of various proteins, such as keratins, vimentin, and lamins. These filaments help maintain cell integrity by resisting mechanical stress and distributing tension across the cell. They also play a role in anchoring organelles in place and are involved in cell signaling and the formation of the nuclear lamina, which supports the nuclear envelope.