Questions and Answers
What is the primary function of the plasma membrane?
Cytoplasm contains 80-85% of lipids.
False
What does DNA stand for?
Deoxyribose nucleic acid
The plasma membrane is composed of a __________ bilayer.
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Match the following cell components with their functions:
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What is the primary function of DNA in cells?
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Fimbrae are primarily involved in motility in bacterial cells.
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Who discovered ribosomes and in what year?
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A flagellum functions in __________ of bacterial cells.
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Match the following structures with their descriptions:
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Study Notes
Lesson Overview
- Objectives include understanding cell organelle functions and differentiating between plant, animal, and bacterial cells.
Plasma Membrane
- Acts as a boundary regulating molecule and ion transport.
- Composed of a phospholipid bilayer with polar heads and nonpolar tails.
- Embedded proteins have various functions crucial to cellular processes.
Cytoplasm
- Semifluid interior predominant in water (80-85%), proteins (10-15%), lipids (2-4%), polysaccharides (1%), and nucleic acids (1%).
- Site for numerous chemical reactions.
DNA (Deoxyribose Nucleic Acid)
- Genetic material in cellular organisms and many viruses.
- Composed of deoxyribose sugars, phosphates, and nitrogen bases.
- Contains information necessary for protein synthesis and replication.
Ribosomes
- Complex structures made of ribosomal RNA and proteins functioning as protein synthesis factories.
- Identified by George E. Palade in 1955, often associated with the endoplasmic reticulum.
Bacterial Cell Structure
- Flagella enable motility, consists of filament, hook, and basal body.
- Different arrangements: monotrichous, lophotrichous, amphitrichous, and peritrichous dictate motility patterns.
- Fimbriae are bristle-like structures aiding in cell adhesion.
- Pili facilitate DNA transfer during conjugation and help with adhesion.
Eukaryotic Cell Structure
- Composed of a plasma membrane, cytoplasm, cytoskeleton, and membrane-enclosed organelles including a nucleus.
Plant Cell Structures
- Cell wall provides protection and support, includes primary wall (cellulose, cutin, waxes), middle lamella (pectin), and secondary wall (cellulose and lignin).
- Plasmodesmata serve as channels for material transport and cellular communication.
- Plastids are involved in food storage and synthesis, including proplastids, chromoplasts, chloroplasts, and leucoplasts.
Animal Cell Structures
- Organelles include nucleus, ribosomes, endoplasmic reticulum (rough and smooth), Golgi apparatus, mitochondria, vacuoles, lysosomes, and centrioles.
- Centrioles are important for organizing microtubules during cell division.
Membrane-Bound Organelles
- Nucleus: Control center of cell; surrounded by nuclear membrane and contains nucleoplasm.
- Endoplasmic Reticulum: Transport system; rough ER synthesizes proteins, while smooth ER synthesizes lipids and carbohydrates.
- Golgi Apparatus: Modifies, packages, and distributes molecules within the cell.
- Vacuoles: Storage organelles, smaller in animal cells.
- Mitochondria: Powerhouse of the cell, sites of ATP generation.
- Lysosomes: Contain digested materials and enzymes; known as "suicidal bags."
- Microbodies: Small organelles with enzymes, e.g., peroxisomes for detoxification.
Non-Membrane Bound Organelles
- Ribosomes: Sites of protein synthesis, consisting of small and large subunits.
- Centrioles: Microtubule-based, aiding in cell division.
- Cytoskeleton: Network of filaments and fibers supporting cell structure and facilitating movement; includes microtubules for support and microfilaments for cytoplasmic streaming.
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Description
This quiz focuses on the key concepts related to cell structures and their functions as discussed in Lesson 3. Students will explore the various components of the cell and understand their roles in biological processes. Engage in this quiz to test your knowledge and enhance your learning experience.
