Podcast Beta
Questions and Answers
What is one of the primary functions of microtubules?
Which statement accurately describes actin filaments?
Which type of filament is found predominantly in muscle cells?
What role do intermediate filaments play in the cell?
Signup and view all the answers
Which of the following is a characteristic of microtubules?
Signup and view all the answers
Which class of intermediate filaments is found in epithelial cells?
Signup and view all the answers
What distinguishes intermediate filaments from microtubules and actin filaments?
Signup and view all the answers
Which of the following is NOT a function of actin filaments?
Signup and view all the answers
Which of the following is NOT a component of the cytoskeleton?
Signup and view all the answers
What is the diameter range of intermediate filaments?
Signup and view all the answers
How many protofilaments form the circumference of each microtubule wall?
Signup and view all the answers
What is the primary function of microtubules in eukaryotic cells?
Signup and view all the answers
Which of the following best describes the structure of microtubules?
Signup and view all the answers
Which of the following processes is associated with the dynamic nature of microtubules?
Signup and view all the answers
What role do the microtubules play in cellular movement?
Signup and view all the answers
Which of the following best describes the function of the cytoskeleton?
Signup and view all the answers
What is the primary role of intermediate filaments of keratins in skin epidermal cells?
Signup and view all the answers
Which protein is considered an important vimentin-like protein found in muscle cells?
Signup and view all the answers
What is the function of lamins in the nuclear envelope?
Signup and view all the answers
What is the size of a functional ribosome?
Signup and view all the answers
Where are ribosomal proteins synthesized before they are assembled into ribosomes?
Signup and view all the answers
What distinguishes free polyribosomes from bound polyribosomes?
Signup and view all the answers
What role do neurofilament proteins play in cells?
Signup and view all the answers
What property makes polyribosomes basophilic in stained preparations of cells?
Signup and view all the answers
What is the main role of proteasomes in the cell?
Signup and view all the answers
Which structure is responsible for recognizing ubiquitinated proteins?
Signup and view all the answers
What is the composition of a centriole?
Signup and view all the answers
Which of the following is NOT a function of the proteasome?
Signup and view all the answers
During which phase of the cell cycle does the centrosome duplicate?
Signup and view all the answers
Which of the following statements about the proteasome's structure is true?
Signup and view all the answers
What type of proteins do proteasomes primarily deal with?
Signup and view all the answers
What happens to the centrosome during mitosis?
Signup and view all the answers
Study Notes
Non-Membranous Organelles
- Cytoskeleton: composed of microfilaments, intermediate filaments, and microtubules.
- Microfilaments: 6 nm in diameter, responsible for cell shape, locomotion, organelle movement, and muscle contraction.
- Microtubules: 25 nm in diameter, maintain cell shape, facilitate intracellular transport, and form structures like mitotic spindles, centrioles, basal bodies, and axoneme of cilia and flagella.
-
Intermediate filaments: 8-10 nm in diameter, stable and diverse, important for cell structure and function depending on cell type.
- Keratins: found in epithelial cells, contribute to keratinization in skin.
- Vimentin: found in mesenchymal cells, and desmin in muscle cells, and GFAP in astrocytes, supporting cells of the central nervous system.
- Neurofilaments: found in neurons.
- Lamins: found in the nuclei of all cells, help maintain nuclear shape and participate in gene transcription.
-
Ribosomes: 20 × 30 nm in size, essential for protein synthesis.
- Made of two subunits: small and large, bound to mRNA.
- Composed of rRNA and proteins.
- Exist as free or bound polyribosomes.
- Free polyribosomes: synthesize cytoplasmic proteins.
- Bound polyribosomes: associated with ER, synthesize membrane proteins, lysosomal enzymes, and secretory proteins.
-
Proteasomes: cylindrical protein complexes that degrade denatured or nonfunctional proteins.
- Recognize proteins marked with ubiquitin.
- Unfold and degrade proteins in their core.
- Play a role in protein quality control and preventing cellular damage.
-
Centrosomes: composed of two centrioles surrounded by pericentriolar matrix (PCM).
- Centrioles are cylindrical with nine microtubule triplets.
- Duplicate during DNA replication.
- Organize microtubules during mitosis, forming the mitotic spindle.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your knowledge on non-membranous organelles including cytoskeleton components such as microfilaments, microtubules, and intermediate filaments. Understand their structures, functions, and importance in cellular behavior. This quiz will challenge your understanding of these critical cellular components.
