Podcast
Questions and Answers
What is the diameter range of ribosomes?
What is the diameter range of ribosomes?
- 40-50 nm
- 30-40 nm
- 20-30 nm (correct)
- 10-20 nm
Which type of ribosome is found in eukaryotes?
Which type of ribosome is found in eukaryotes?
- 70S ribosome
- 50S ribosome
- 60S ribosome
- 80S ribosome (correct)
What is the function of the A site in a ribosome?
What is the function of the A site in a ribosome?
- Holds the tRNA carrying the growing polypeptide chain
- Holds the discharged tRNAs as they exit the ribosome
- Holds the tRNA for termination of translation
- Holds the tRNA carrying the next amino acid (correct)
How many proteins are in a large ribosomal subunit of a 70S ribosome?
How many proteins are in a large ribosomal subunit of a 70S ribosome?
What type of proteins do ribosomes attached to the rough endoplasmic reticulum generally synthesize?
What type of proteins do ribosomes attached to the rough endoplasmic reticulum generally synthesize?
Which subunit comprises the small ribosomal subunit of a 70S ribosome?
Which subunit comprises the small ribosomal subunit of a 70S ribosome?
What does the E site of a ribosome do?
What does the E site of a ribosome do?
What is the primary function of ribosomes?
What is the primary function of ribosomes?
What is the main structural feature of centrioles?
What is the main structural feature of centrioles?
During which cellular process do centrioles play a crucial role?
During which cellular process do centrioles play a crucial role?
Which of the following is NOT a function of the rough endoplasmic reticulum (rER)?
Which of the following is NOT a function of the rough endoplasmic reticulum (rER)?
What is the primary difference between the rough and smooth endoplasmic reticulum?
What is the primary difference between the rough and smooth endoplasmic reticulum?
Which characteristic is true for centrioles in animal cells?
Which characteristic is true for centrioles in animal cells?
What is the process by which the rough endoplasmic reticulum is fragmented into microsomes?
What is the process by which the rough endoplasmic reticulum is fragmented into microsomes?
What does the presence of ribosomes on the rough endoplasmic reticulum indicate?
What does the presence of ribosomes on the rough endoplasmic reticulum indicate?
What type of cellular organelle would you find only in animal cells that is involved in organizing spindle fibers?
What type of cellular organelle would you find only in animal cells that is involved in organizing spindle fibers?
What is the role of the lysosome in the cellular process described?
What is the role of the lysosome in the cellular process described?
Where do polypeptide chains undergo folding to achieve their 3D shape?
Where do polypeptide chains undergo folding to achieve their 3D shape?
What occurs after the polypeptides are transported from the RER to the Golgi apparatus?
What occurs after the polypeptides are transported from the RER to the Golgi apparatus?
Which process directly leads to the production of mRNA?
Which process directly leads to the production of mRNA?
What type of modification may occur to polypeptide chains in the Golgi apparatus?
What type of modification may occur to polypeptide chains in the Golgi apparatus?
How do mRNA molecules leave the nucleus?
How do mRNA molecules leave the nucleus?
What happens to the products of hydrolysis performed by lysosomal enzymes?
What happens to the products of hydrolysis performed by lysosomal enzymes?
Which structure buds out from the trans face of the Golgi apparatus?
Which structure buds out from the trans face of the Golgi apparatus?
What is the primary function of the nuclear pores?
What is the primary function of the nuclear pores?
What structural feature of mitochondria increases the surface area for energy-producing processes?
What structural feature of mitochondria increases the surface area for energy-producing processes?
What occurs to the nuclear envelope during mitosis and meiosis?
What occurs to the nuclear envelope during mitosis and meiosis?
Which of the following statements about nucleoplasm is true?
Which of the following statements about nucleoplasm is true?
Which component of mitochondria is primarily involved in ATP synthesis?
Which component of mitochondria is primarily involved in ATP synthesis?
What is the relationship between the mitochondrial matrix and the Krebs cycle?
What is the relationship between the mitochondrial matrix and the Krebs cycle?
What distinguishes the double membrane structure of mitochondria?
What distinguishes the double membrane structure of mitochondria?
How do nuclear pores contribute to maintaining chemical environments within the nucleus?
How do nuclear pores contribute to maintaining chemical environments within the nucleus?
What is the primary function of the enzymes in the Golgi body related to proteins and lipids?
What is the primary function of the enzymes in the Golgi body related to proteins and lipids?
Which process occurs first during the modification of glycoproteins in the cell?
Which process occurs first during the modification of glycoproteins in the cell?
What happens to hydrolytic enzymes within lysosomes?
What happens to hydrolytic enzymes within lysosomes?
Which of the following accurately describes how proteins are sorted in the Golgi body?
Which of the following accurately describes how proteins are sorted in the Golgi body?
What characteristic of lysosomal contents helps to maintain its function?
What characteristic of lysosomal contents helps to maintain its function?
What is NOT a type of protein sorting that occurs in the Golgi body?
What is NOT a type of protein sorting that occurs in the Golgi body?
What role does pectin play in plant cells?
What role does pectin play in plant cells?
How are glycoproteins modified after initial carbohydrate addition?
How are glycoproteins modified after initial carbohydrate addition?
Study Notes
Ribosomes
- Organelles composed of ribosomal RNA and proteins, measuring 20-30 nm in diameter.
- Consist of two subunits: small (30S in prokaryotes; 40S in eukaryotes) and large (50S in prokaryotes; 60S in eukaryotes).
- Two types: 70S found in prokaryotes, mitochondria, and chloroplasts; 80S found in eukaryotes.
- Have three binding sites for tRNA: A site (aminoacyl), P site (peptidyl), E site (exit).
- Main function is protein synthesis, with bound ribosomes (on rough ER) creating proteins for membranes and organelles, while free ribosomes synthesize cytosolic proteins.
Centrioles
- Measure approximately 0.2 µm in diameter and 0.3 to 0.5 nm in length.
- Composed of 9 triplets of microtubules, forming a rod-like structure positioned at 90° to each other.
- Exclusively found in animal cells.
- Function to organize spindle fibers during cell division and serve as anchorage for cilia and flagella.
Endoplasmic Reticulum (ER)
- Composed of membrane-bound sacs called cisternae, serving different roles in synthesis and packaging.
- Types: Rough Endoplasmic Reticulum (rER) and Smooth Endoplasmic Reticulum (sER).
Rough Endoplasmic Reticulum (rER)
- Flattened cisternae interconnected with the outer nuclear membrane; ribosomes on the surface contribute to a rough appearance.
- Ribosomes facilitate protein synthesis and initial glycoprotein formation.
- Modifies proteins and lipids chemically; enzymes add carbohydrates to proteins, forming glycoproteins and glycolipids.
- Sorts and packages molecules for transport to other organelles or cell secretion, including lysosomal enzymes and membrane proteins.
Lysosomes
- Spherical sacs measuring 0.2 - 0.5 µm in diameter, containing hydrolytic enzymes (proteases, lipases).
- Store enzymes separately to prevent cellular damage, maintaining an acidic environment for optimal enzyme activity.
Nucleus and Nuclear Envelope
- Nuclear pores enable selective exchange of molecules (e.g., mRNA) between the nucleus and cytoplasm.
- The nuclear envelope disintegrates during cell division (mitosis and meiosis), maintaining a distinct internal chemical environment.
Mitochondria
- Organelles responsible for ATP synthesis via glucose metabolism, measuring 1.5 – 10 µm in length and 0.25 - 1.00 µm in width.
- Feature a double membrane: outer membrane smooth, inner membrane folded into cristae to increase surface area for ETC and oxidative phosphorylation.
- Contains mitochondrial DNA, 70S ribosomes, RNAs, and enzymes for the Krebs cycle.
- Primary function is energy (ATP) production through catabolic respiratory activities within the cell.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your knowledge on the structure and function of ribosomes. This quiz covers the composition, types, and characteristics of ribosomes found in prokaryotes and eukaryotes. Perfect for biology students looking to enhance their understanding of cellular components.
