Week 3 Seminar Cell Structure and Functions Quiz
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Questions and Answers

What is the primary role of the Golgi apparatus in a eukaryotic cell?

The Golgi apparatus processes, packages, and distributes proteins and lipids throughout the cell.

How do lysosomes contribute to digestion within the cell?

Lysosomes contain digestive enzymes that break down waste materials and cellular debris.

What is the function of centrioles during cell division?

Centrioles help organize the spindle fibers that separate chromosomes during mitosis.

What are the main functions of vacuoles in a eukaryotic cell?

<p>Vacuoles store nutrients, waste products, and help maintain turgor pressure in plant cells.</p> Signup and view all the answers

Describe the structure and role of ribosomes in the cell.

<p>Ribosomes are composed of ribosomal RNA and proteins, facilitating protein synthesis.</p> Signup and view all the answers

Why are organelles considered essential in eukaryotic cells?

<p>Organelles perform specific functions necessary for the survival and maintenance of the cell.</p> Signup and view all the answers

What distinguishes eukaryotic cells from prokaryotic cells in terms of organelles?

<p>Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not.</p> Signup and view all the answers

What are the implications of the nucleus being referred to as the 'control center' of the cell?

<p>The nucleus houses the cell's DNA and regulates gene expression and cellular activities.</p> Signup and view all the answers

What is the primary function of the nucleolus in a eukaryotic cell?

<p>The nucleolus is responsible for producing and assembling the cell’s ribosomes.</p> Signup and view all the answers

Explain the role of the plasma membrane in cellular function.

<p>The plasma membrane acts as a barrier that regulates the entry and exit of materials, making it selectively permeable.</p> Signup and view all the answers

What is the approximate water content of the cytoplasm?

<p>The cytoplasm contains about 80% water.</p> Signup and view all the answers

Differentiate between the rough and smooth endoplasmic reticulum.

<p>Rough ER is involved in protein production and quality control, while smooth ER is associated with lipid production and detoxification.</p> Signup and view all the answers

What important function do mitochondria perform in eukaryotic cells?

<p>Mitochondria are primarily involved in producing energy through ATP synthesis.</p> Signup and view all the answers

Identify the key components of the ribosome's structure.

<p>Ribosomes are composed of ribosomal RNA (rRNA) and proteins.</p> Signup and view all the answers

Describe the function of lysosomes in cellular digestion.

<p>Lysosomes contain enzymes that break down waste materials and cellular debris.</p> Signup and view all the answers

What roles do vacuoles play in cells?

<p>Vacuoles function in storage and maintaining turgor pressure within plant cells.</p> Signup and view all the answers

What is the role of centrioles during cell division?

<p>Centrioles help in organizing the microtubules that separate chromosomes during cell division.</p> Signup and view all the answers

How does the Golgi complex process proteins?

<p>The Golgi complex modifies, sorts, and packages proteins for secretion or delivery to other organelles.</p> Signup and view all the answers

What types of proteins are synthesized by ribosomes?

<p>Ribosomes synthesize all types of proteins, including enzymes, structural proteins, and hormones.</p> Signup and view all the answers

What is the significance of the selectively permeable nature of the plasma membrane?

<p>It allows cells to control their internal environment by regulating which substances enter and exit.</p> Signup and view all the answers

In what ways do mitochondria contribute to cellular metabolism?

<p>Mitochondria are involved in aerobic respiration and energy production via ATP.</p> Signup and view all the answers

What types of reactions typically occur in the cytoplasm?

<p>The cytoplasm is the site of enzymatic reactions, such as glycolysis and protein synthesis.</p> Signup and view all the answers

What is the primary function of the Golgi apparatus in a cell?

<p>The Golgi apparatus processes and packages secretory proteins and synthesizes complex polysaccharides.</p> Signup and view all the answers

How do lysosomes contribute to cellular digestion?

<p>Lysosomes contain enzymes that digest specific biological molecules and help in breaking down dead or damaged cells.</p> Signup and view all the answers

Describe the role of centrioles during cell division.

<p>Centrioles organize the assembly of microtubules, which are essential for separating chromosomes during cell division.</p> Signup and view all the answers

What functions do vacuoles perform in a cell?

<p>Vacuoles are responsible for storing water, nutrients, and waste products, aiding in the removal of harmful substances.</p> Signup and view all the answers

What is the structure of ribosomes and their main function?

<p>Ribosomes consist of two subunits (large 60s and small 40s) and synthesize proteins based on mRNA sequences.</p> Signup and view all the answers

How does the Golgi apparatus modify macromolecules?

<p>The Golgi complex modifies macromolecules through processes like glycosylation and phosphorylation.</p> Signup and view all the answers

Explain how lysosomes help in the removal of waste in cells.

<p>Lysosomes digest unwanted biological materials, allowing for the removal of cellular waste and damaged components.</p> Signup and view all the answers

What role do centrioles play in microtubule organization?

<p>Centrioles serve as the organizing center for microtubules, facilitating their assembly during cell division.</p> Signup and view all the answers

What are the storage functions of vacuoles in plant and animal cells?

<p>Vacuoles store substances such as water, lipids, and nutrients, and help remove waste products from the cell.</p> Signup and view all the answers

In what way do ribosomes differ in their locations within the cell?

<p>Ribosomes can either float freely in the cytoplasm or be attached to the endoplasmic reticulum.</p> Signup and view all the answers

How do lysosomes digest damaged organelles?

<p>Lysosomes use their digestive enzymes to break down damaged organelles into basic components.</p> Signup and view all the answers

What is the significance of the number of mitochondria in a cell?

<p>The number of mitochondria in a cell varies depending on the cell's energy demands, with more present in high-energy tissues.</p> Signup and view all the answers

What modifications do proteins undergo in the Golgi apparatus?

<p>Proteins are modified through glycosylation, where sugars are added, and phosphorylation, where phosphate groups are added.</p> Signup and view all the answers

Describe the relationship between centrioles and microtubules during cell division.

<p>Centrioles facilitate the organization and assembly of microtubules, which form the spindle fibers during cell division.</p> Signup and view all the answers

Which of the following organelles is surrounded by a double membrane?

<p>Nucleus</p> Signup and view all the answers

What is a distinctive feature of eukaryotic cells regarding organelles?

<p>They possess membrane-bound organelles.</p> Signup and view all the answers

Which organelle contains the majority of the cell's DNA?

<p>Nucleus</p> Signup and view all the answers

Which of the following organelles is not membrane-bound?

<p>Ribosome</p> Signup and view all the answers

What is the primary function of the nucleolus within the nucleus?

<p>Ribosomal RNA synthesis</p> Signup and view all the answers

How many nuclei are typically present in a eukaryotic cell?

<p>One, generally</p> Signup and view all the answers

Which of the following organelles is NOT found in prokaryotic cells?

<p>Nucleus</p> Signup and view all the answers

What role do organelles play in cells?

<p>They perform specific functions to keep the cell alive.</p> Signup and view all the answers

What is the primary function of cilia in eukaryotic cells?

<p>To aid in locomotion</p> Signup and view all the answers

What defines a differentiated cell?

<p>It only expresses genes for specific proteins</p> Signup and view all the answers

What characteristic distinguishes stem cells from differentiated cells?

<p>Stem cells are undifferentiated and can become any cell type</p> Signup and view all the answers

Which statement about prokaryotes is true?

<p>They only have flagella but no cilia</p> Signup and view all the answers

Why are differentiated cells essential in multicellular organisms?

<p>They can perform specialized functions within the body</p> Signup and view all the answers

What is the term used to describe stem cells that can develop into any cell type?

<p>Totipotent</p> Signup and view all the answers

Which of the following is NOT a characteristic of differentiated cells?

<p>They express all genes present in their genome</p> Signup and view all the answers

What role do stem cells play in multicellular organisms?

<p>They produce specialized differentiated cells as needed</p> Signup and view all the answers

What is the primary function of nucleoli in eukaryotic cells?

<p>Assemble and produce ribosomes</p> Signup and view all the answers

Which of the following correctly describes the plasma membrane?

<p>Made predominantly of phospholipids and selectively permeable</p> Signup and view all the answers

What is the main component of the cytoplasm?

<p>80% water</p> Signup and view all the answers

What are the two types of endoplasmic reticulum (ER) found in eukaryotic cells?

<p>Rough and smooth ER</p> Signup and view all the answers

Which function is primarily associated with smooth endoplasmic reticulum (ER)?

<p>Production of lipids and detoxification</p> Signup and view all the answers

What role does the cytoplasm play in the cell?

<p>Site for many important chemical reactions</p> Signup and view all the answers

What best describes the function of mitochondria in cells?

<p>Powerhouse of the cell, generating energy</p> Signup and view all the answers

Which of the following statements is true regarding the plasma membrane?

<p>It regulates the entry and exit of substances.</p> Signup and view all the answers

What is the characteristic structure of rough endoplasmic reticulum?

<p>It has ribosomes attached to its surface.</p> Signup and view all the answers

What is the main role of receptors in the plasma membrane?

<p>Facilitate signal transduction and communication</p> Signup and view all the answers

What type of reactions typically occur within the mitochondria?

<p>Aerobic respiration reactions</p> Signup and view all the answers

What part of the cell does the cytoplasm encompass?

<p>Everything inside the plasma membrane excluding the nucleus</p> Signup and view all the answers

Which statement is true regarding cellular transport proteins in the plasma membrane?

<p>They facilitate the movement of substances across the membrane.</p> Signup and view all the answers

What distinguishes rough ER from smooth ER?

<p>Rough ER has ribosomes, whereas smooth ER does not.</p> Signup and view all the answers

What is the primary function of microvilli in cells?

<p>Increase surface area for nutrient absorption</p> Signup and view all the answers

Which of the following describes the role of the cell wall?

<p>It provides mechanical strength and structural support.</p> Signup and view all the answers

What is the primary site of photosynthesis in plant cells?

<p>Chloroplasts</p> Signup and view all the answers

What is one of the main functions of a large vacuole in plant cells?

<p>Hold food and water for later use</p> Signup and view all the answers

Which statement accurately describes chloroplasts?

<p>Contain chlorophyll and are involved in photosynthesis.</p> Signup and view all the answers

What is the function of the cell wall in relation to turgor pressure?

<p>It supports a rigid structure to withstand turgor pressure.</p> Signup and view all the answers

How does the structure of microvilli benefit nutrient absorption?

<p>Enhances surface area for absorption</p> Signup and view all the answers

Which function is NOT associated with chloroplasts?

<p>Production of cellular energy</p> Signup and view all the answers

What role do large vacuoles play in preventing plant wilting?

<p>They maintain turgor pressure.</p> Signup and view all the answers

Which of the following is a characteristic of the cell wall?

<p>It provides a protective barrier and mechanical support.</p> Signup and view all the answers

What differentiates mitochondrial DNA from nuclear DNA?

<p>Mitochondrial DNA is circular, while nuclear DNA is linear.</p> Signup and view all the answers

Which of the following is NOT a role of the Golgi apparatus?

<p>Production of ATP</p> Signup and view all the answers

What is the function of lysosomes?

<p>Digest biological molecules and remove waste</p> Signup and view all the answers

What is the primary characteristic of ribosomes?

<p>They synthesize proteins based on mRNA.</p> Signup and view all the answers

In which types of cells are centrioles found?

<p>All animal cells and some plant cells</p> Signup and view all the answers

How do vacuoles assist in cellular function?

<p>They remove and store wastes and nutrients.</p> Signup and view all the answers

Which statement about mitochondria is true?

<p>Mitochondria are the site of cellular respiration.</p> Signup and view all the answers

What is the role of microvilli in cells?

<p>To increase surface area for absorption</p> Signup and view all the answers

Which characteristic distinguishes two subunits of ribosomes?

<p>Their size, shape, and composition</p> Signup and view all the answers

What process occurs in the mitochondria?

<p>Cellular respiration</p> Signup and view all the answers

What outcome might result from a cell with a high number of mitochondria?

<p>Enhanced energy production</p> Signup and view all the answers

What is a primary function of the Golgi apparatus related to proteins?

<p>Modification and packaging for export</p> Signup and view all the answers

What type of product do lysosomes primarily handle?

<p>Biological molecules, including damaged cells</p> Signup and view all the answers

What is a characteristic of vacuoles in plant cells?

<p>They play a critical role in maintaining turgor pressure.</p> Signup and view all the answers

Study Notes

Nucleus

  • Present in eukaryotic cells only
  • Surrounded by a double membrane called the nuclear envelope
  • Contains the majority of the cell’s DNA in the form of chromosomes
  • The "brain" of the cell that controls cell activities
  • Controls inheritance and metabolism
  • Usually one nucleus per cell, although there may be more than one in skeletal muscle cells.

Nucleolus

  • Located within the nucleus
  • Produces and assembles ribosomes

Plasma Membrane

  • Present in both prokaryotic and eukaryotic cells
  • The barrier between the inside of the cell and the outer environment
  • Primarily composed of phospholipids, making it selectively permeable
  • Contains receptors (protein molecules) and transport proteins that carry out various cellular tasks

Cytoplasm

  • Found inside the plasma membrane in prokaryotic cells and within the cell surrounding the nucleus in eukaryotic cells
  • Contains approximately 80% water, along with organic and inorganic compounds
  • Other organelles are embedded in the cytoplasm
  • The site of many important chemical reactions

Endoplasmic Reticulum (ER)

  • A network of elongated sacs and membranous canals filled with fluid
  • Acts as the transportation system of the cell
  • Rough ER is involved in the production, folding, quality control, and dispatch of proteins
  • Smooth ER is associated with the production of lipids and steroids and is responsible for detoxifying the cell

Mitochondria

  • Often referred to as the "powerhouse" of the cell
  • Contains a set of DNA different from the nucleus
  • The site of cellular respiration, converting energy from food into ATP
  • Cells with high energy demands have many mitochondria
  • Play a role in calcium storage and cell death (apoptosis)

Golgi Apparatus

  • The "post office" of the cell
  • Processes and packages secretory proteins, synthesizing complex polysaccharides
  • Materials to be exported from the cell are packaged into secretory vesicles after being processed by the Golgi complex
  • Modifies macromolecules through glycosylation and phosphorylation

Ribosomes

  • Function as "factories" where proteins are synthesized based on mRNA
  • Some float freely in the cytoplasm, while others are attached to the ER
  • Consists of two subunits that differ in size, shape, and composition
  • The large subunit in human cells is 60s, while the small subunit in human cells is 40s

Lysosomes

  • Store enzymes that digest specific biological molecules
  • Aid in digestion and waste removal
  • Digest dead and damaged cells

Centrioles

  • Found in all animal cells and some plant cells
  • Cylindrical structures composed of groupings of microtubules
  • Organize the assembly of microtubules during cell division

Vacuoles

  • Remove and store wastes or harmful foreign products
  • Store water and nutrients such as lipids, proteins, and carbohydrates

Microvilli

  • Finger-like projections from the plasma membrane
  • Increase surface area for absorption

Organelles

  • Organelles are the "tiny organs" of a cell
  • Organelles perform specific functions to keep a cell alive
  • Some organelles are membrane-bound and some are not.
    • Single membrane-bound: vacuole, lysosome, Golgi apparatus, endoplasmic reticulum (present in eukaryotic cells only)
    • Double membrane-bound: nucleus, mitochondria and chloroplast (present in eukaryotic cells only)
    • Organelles without membrane: cell wall, ribosomes, cytoskeleton (present in both prokaryotic and eukaryotic cells)
  • The presence of organelles is a key distinction of a eukaryotic cell

Nucleus

  • Present in eukaryotic cells only
  • Surrounded by a double membrane called nuclear envelope
  • Contains the majority of the cell's DNA in the form of chromosomes
  • Known as the "headquarters" or "brain" of the cell
  • Controls the activities of the cell
  • Controls inheritance and metabolism
  • Typically one nucleus per cell, but can be more than one (e.g., skeletal muscle cells)

Nucleolus

  • Plural: nucleoli
  • A spherical structure present in the nucleus of a eukaryotic cell
  • Produces and assembles the cell's ribosomes
  • Involved in the synthesis and assembly of ribosomal RNA (rRNA)

Plasma Membrane

  • Present in both prokaryotic and eukaryotic cells
  • The barrier between the inside of the cell and the outer environment
  • Predominantly made of phospholipids, which make it selectively permeable
  • Allows the controlled entry and exit of materials necessary for the cell
  • Contains receptors (protein molecules) and transport proteins that perform cellular functions

Cytoplasm

  • Everything found inside the plasma membrane of a prokaryotic cell, or the interior of a eukaryotic cell that surrounds the nucleus
  • Composed of ~80% water, along with organic and inorganic compounds
  • Other organelles of the cell are embedded in the cytoplasm
  • A site for many important chemical reactions

Endoplasmic Reticulum (ER)

  • Elongated, membranous sacs and canals filled with fluid
  • The transportation system of the cell
  • Rough ER: involved in protein synthesis, folding, quality control, and dispatch
  • Smooth ER: associated with lipid and steroid production and cell detoxification

Mitochondria

  • Plural: mitochondria
  • The number of mitochondria per cell varies widely
  • Contains a set of DNA different from the nucleus
  • The "powerhouse" of the cell where cellular respiration occurs
  • Converts energy from food into ATP (adenosine triphosphate)
  • Tissues with high ATP demands contain many mitochondria
  • Also plays a role in calcium storage and programmed cell death (apoptosis)

Golgi Apparatus

  • The "post office" of the cell
  • Processes and packages secretory proteins and synthesizes complex polysaccharides
  • Once processed, materials destined for cell export are packaged into secretory vesicles
  • Modifies macromolecules through glycosylation and phosphorylation

Ribosomes

  • The "factories" where proteins are synthesized based on mRNA instructions
  • Some ribosomes float freely in the cytoplasm, while others are attached to the ER
  • Composed of two subunits that differ in size, shape, and composition:
    • Large subunit in human cells: 60s
    • Small subunit in human cells: 40s

Lysosomes

  • Storage containers for enzymes that digest specific biological molecules
  • Assist in digesting and removing wastes
  • Break down dead and damaged cells

Centrioles

  • Found in all animal cells and some plant cells
  • Cylindrical cell structures composed of groupings of microtubules
  • Organize the assembly of microtubules during cell division

Vacuoles

  • Remove and store wastes and harmful foreign products
  • Store water and nutrients: lipids, proteins, and carbohydrates

Microvilli

  • Plural: microvilli
  • Tiny finger-like protrusions from the plasma membrane surface
  • Primary surface of nutrient absorption
  • Increase the surface area of the absorbing region

Cell Wall

  • Lies outside of the cell membrane
  • Found in plant cells, some bacteria, and some fungi
  • Provides mechanical strength and structural support
  • Serves as a physical barrier for protection and resistance to turgor pressure
  • Controls cell growth direction and cell cycle regulation

Chloroplasts

  • Found in plant cells, some bacteria, fungi, and algae
  • Site of photosynthesis in plants and algae, which use solar energy
  • Produce chlorophyll
  • Can be numerous in green plant cells

Large Vacuole

  • A storage area for the cell
  • Holds food and water
  • Holds waste for removal
  • Maintains the turgor pressure that keeps the plant from wilting

Organelles of Locomotion

  • Flagellum (pl. flagella): Long, whip-like structures used for movement
  • Cilia (pl. cilia): Short, hair-like structures that beat in a coordinated motion, propelling the cell or moving fluids past the cell.

Cilia and Flagella

  • Hairlike structures that aid cell locomotion
  • Found outside the cytoplasm
  • Cilia and flagella are present in eukaryotic cells
  • Prokaryotes have flagella but not cilia

Cell Differentiation

  • Cells are membrane-bound groups of organelles that work together for function
  • Cell differentiation occurs when cells express specific genes characteristic of a certain cell type
  • Once a cell differentiates, it only expresses genes that produce proteins for that cell type
  • Differentiated cells are crucial for multicellular organisms as they perform specialized functions

Stem Cells

  • Multicellular organisms need undifferentiated cells to replenish cells
  • Stem cells are undifferentiated cells
  • Stem cells are described as totipotent, meaning they can differentiate into any cell type

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Cells and Organelles PDF

Description

Test your knowledge on the structures and functions of cell components including the nucleus, nucleolus, plasma membrane, and cytoplasm. This quiz will cover key characteristics of eukaryotic and prokaryotic cells and their organelles.

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