Questions and Answers
Prokaryotic cells are generally ___ in size.
small (1-10 µm)
Eukaryotic cells have well-defined nuclear regions surrounded by a ___ membrane.
nuclear
Which of the following statements is true about prokaryotic cells?
What are the two types of endoplasmic reticulum?
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Eukaryotic cells lack membrane-bound organelles.
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What is one function of the smooth endoplasmic reticulum?
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Name an organelle that carries out crucial functions in cells.
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The ER varies in structure; it always forms a ___ system.
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Study Notes
Prokaryotic vs. Eukaryotic Cells
- Prokaryotic cells are generally small, measuring 1-10 µm in size, while eukaryotic cells range from 5-100 µm.
- Prokaryotic cells have an undefined nuclear region, known as a nucleoid, whereas eukaryotic cells feature a well-defined nucleus enclosed by a nuclear membrane.
- Prokaryotic cells possess a single chromosome, in contrast to eukaryotic cells, which contain multiple chromosomes.
- Membrane-bound organelles are absent in prokaryotic cells, but present in eukaryotic cells.
Endoplasmic Reticulum (ER)
- The ER is a network of membrane-bound tubes and sheets, resembling long tubules and vesicles.
- Its membrane structure is similar to that of the plasma membrane, facilitating cellular functions.
- There are two main types of ER:
- Rough Endoplasmic Reticulum (RER): Characterized by ribosomes on its surface, giving it a rough appearance under a microscope. Ribosomes are essential for protein synthesis, and the RER transports proteins to various cell regions.
- Smooth Endoplasmic Reticulum (SER): Lacks ribosomes and is involved in lipid (fat molecule) synthesis, contributing to cell membrane formation and serving some proteins and lipids as enzymes and hormones.
- The ER's structure varies, forming a complex network essential for cell functionality.
Cell Organelles
- All cells possess a membrane to maintain compartmentalization between internal contents and the external environment.
- Larger, more complex cells require numerous chemical activities, leading to extensive structures known as organelles, which are crucial for separating these activities.
- Membrane-bound organelles are a defining feature of eukaryotic cells, distinguishing them from prokaryotic cells.
- Some organelles are visible only with an electron microscope.
- Key organelles include:
- Endoplasmic Reticulum (ER)
- Golgi Apparatus
- Lysosomes
- Mitochondria
- Plastids
- These organelles perform vital functions necessary for cellular operations, such as:
- Acting as transport channels for materials between different cytoplasmic regions and the nucleus.
- Providing a cytoplasmic framework that offers a surface for various chemical reactions and processes.
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Description
Test your knowledge on cell organelles, focusing on the differences between prokaryotic and eukaryotic cells. This quiz includes fill-in-the-blank questions to help reinforce your understanding of cell structure and function.
