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Questions and Answers
Which of the following is NOT a type of organelle found within eukaryotic cells?
Which of the following is NOT a type of organelle found within eukaryotic cells?
Which organelle is responsible for modifying, sorting, and packaging proteins and lipids?
Which organelle is responsible for modifying, sorting, and packaging proteins and lipids?
What is the primary function of the rough endoplasmic reticulum (ER)?
What is the primary function of the rough endoplasmic reticulum (ER)?
Which organelle is responsible for breaking down cellular waste products and debris?
Which organelle is responsible for breaking down cellular waste products and debris?
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Both plant and animal cells share a common set of organelles. Which of the following is NOT present in both?
Both plant and animal cells share a common set of organelles. Which of the following is NOT present in both?
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Which of the following are components of the cytoskeleton, which is responsible for cell shape and movement?
Which of the following are components of the cytoskeleton, which is responsible for cell shape and movement?
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What is the primary function of the nucleus?
What is the primary function of the nucleus?
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Which of the following is NOT a characteristic of eukaryotes?
Which of the following is NOT a characteristic of eukaryotes?
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What is the primary function of the endoplasmic reticulum?
What is the primary function of the endoplasmic reticulum?
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Which of the following is NOT a component of the endomembrane system?
Which of the following is NOT a component of the endomembrane system?
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What distinguishes rough endoplasmic reticulum from smooth endoplasmic reticulum?
What distinguishes rough endoplasmic reticulum from smooth endoplasmic reticulum?
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Which of the following is a primary role of the Golgi apparatus?
Which of the following is a primary role of the Golgi apparatus?
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How do the different components of the endomembrane system communicate?
How do the different components of the endomembrane system communicate?
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Which of these is a key difference between the rough endoplasmic reticulum and the smooth endoplasmic reticulum?
Which of these is a key difference between the rough endoplasmic reticulum and the smooth endoplasmic reticulum?
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What is the function of the nuclear envelope in relation to the endomembrane system?
What is the function of the nuclear envelope in relation to the endomembrane system?
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Which component of the endomembrane system is responsible for modifying and packaging proteins?
Which component of the endomembrane system is responsible for modifying and packaging proteins?
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What is the name of the internal membrane-bound compartments in chloroplasts that are arranged in stacks called grana?
What is the name of the internal membrane-bound compartments in chloroplasts that are arranged in stacks called grana?
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What is the primary difference between the inner membrane space of mitochondria and the stroma of chloroplasts?
What is the primary difference between the inner membrane space of mitochondria and the stroma of chloroplasts?
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The theory of endosymbiosis suggests that mitochondria and chloroplasts originated from:
The theory of endosymbiosis suggests that mitochondria and chloroplasts originated from:
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What is the main function of the mitochondrial cristae?
What is the main function of the mitochondrial cristae?
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What is the primary difference between the process of binary fission used by bacteria and the process of cell division used by eukaryotic cells?
What is the primary difference between the process of binary fission used by bacteria and the process of cell division used by eukaryotic cells?
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Which of the following statements supports the endosymbiotic theory of the origin of mitochondria and chloroplasts?
Which of the following statements supports the endosymbiotic theory of the origin of mitochondria and chloroplasts?
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What is the function of the peroxisome in a eukaryotic cell?
What is the function of the peroxisome in a eukaryotic cell?
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Which of the following statements accurately describes the relationship between mitochondria and chloroplasts?
Which of the following statements accurately describes the relationship between mitochondria and chloroplasts?
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What are ribosomes made of?
What are ribosomes made of?
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What is the role of the signal peptide in protein synthesis?
What is the role of the signal peptide in protein synthesis?
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Which of the following is NOT a characteristic of a protein destined for the nucleus?
Which of the following is NOT a characteristic of a protein destined for the nucleus?
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What is the function of the Golgi apparatus in protein synthesis?
What is the function of the Golgi apparatus in protein synthesis?
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What is the function of lysosomes in protein synthesis?
What is the function of lysosomes in protein synthesis?
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Based on the provided information, what could be the potential fate of a protein with a signal sequence similar to "Ser-Lys-Leu"?
Based on the provided information, what could be the potential fate of a protein with a signal sequence similar to "Ser-Lys-Leu"?
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What does the term "multi-protein complex" refer to?
What does the term "multi-protein complex" refer to?
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Which of the following processes does NOT directly involve proteins?
Which of the following processes does NOT directly involve proteins?
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What pH level is maintained by proton pumps in the lysosomal membrane for optimal enzyme activity?
What pH level is maintained by proton pumps in the lysosomal membrane for optimal enzyme activity?
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Which of the following functions is performed by vacuoles in plant cells?
Which of the following functions is performed by vacuoles in plant cells?
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Which type of cell organelle is responsible for breaking down damaged or defective organelles?
Which type of cell organelle is responsible for breaking down damaged or defective organelles?
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What is the primary metabolic role of mitochondria in cells?
What is the primary metabolic role of mitochondria in cells?
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Which of the following components do mitochondria have that is specifically adapted for their function?
Which of the following components do mitochondria have that is specifically adapted for their function?
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In which type of cells could you expect to find a higher number of mitochondria?
In which type of cells could you expect to find a higher number of mitochondria?
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Which of the following is a similarity between lysosomes and vacuoles?
Which of the following is a similarity between lysosomes and vacuoles?
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Which statement is true about lysosomes?
Which statement is true about lysosomes?
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Which of the following correctly describes the process that occurs to proinsulin?
Which of the following correctly describes the process that occurs to proinsulin?
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What is exocytosis in the context of insulin secretion?
What is exocytosis in the context of insulin secretion?
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What is the primary function of lysosomes?
What is the primary function of lysosomes?
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Which of the following best describes the modification of proteins in the endomembrane system?
Which of the following best describes the modification of proteins in the endomembrane system?
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What hormone's synthesis and secretion involve the endomembrane system?
What hormone's synthesis and secretion involve the endomembrane system?
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In what cellular process is the Golgi body primarily involved?
In what cellular process is the Golgi body primarily involved?
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What is diabetes mellitus typically a result of?
What is diabetes mellitus typically a result of?
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Flashcards
Ribosomes
Ribosomes
Complexes of rRNA and proteins that synthesize proteins.
Free ribosomes
Free ribosomes
Ribosomes that float in cytosol and synthesize proteins for the cell's use.
Bound ribosomes
Bound ribosomes
Ribosomes attached to the endoplasmic reticulum, making protein for export or membrane use.
Protein synthesis
Protein synthesis
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Signal peptide
Signal peptide
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Nuclear localization signal (NLS)
Nuclear localization signal (NLS)
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Golgi apparatus function
Golgi apparatus function
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Secretory vesicles
Secretory vesicles
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Eukaryotic Cell
Eukaryotic Cell
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Organelle
Organelle
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Nucleus
Nucleus
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Endomembrane System
Endomembrane System
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Endoplasmic Reticulum (ER)
Endoplasmic Reticulum (ER)
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Mitochondria
Mitochondria
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Chloroplasts
Chloroplasts
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Cytoskeleton
Cytoskeleton
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Nuclear Envelope
Nuclear Envelope
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Rough ER
Rough ER
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Smooth ER
Smooth ER
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Golgi Apparatus
Golgi Apparatus
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Vesicles
Vesicles
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Lysosomes
Lysosomes
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Insulin
Insulin
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Preproinsulin
Preproinsulin
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Proinsulin
Proinsulin
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Exocytosis
Exocytosis
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Hydrolysis
Hydrolysis
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Proton pumps
Proton pumps
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Autophagy
Autophagy
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Vacuoles
Vacuoles
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Central vacuole
Central vacuole
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Cristae
Cristae
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Cellular respiration
Cellular respiration
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Inner membrane of mitochondrion
Inner membrane of mitochondrion
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Intermembrane space
Intermembrane space
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Mitochondrial matrix
Mitochondrial matrix
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Thylakoid
Thylakoid
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Stroma
Stroma
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Endosymbiosis theory
Endosymbiosis theory
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Evidence of endosymbiosis
Evidence of endosymbiosis
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Study Notes
Course Information
- Course name: Biology 1 – Cells, Molecular Biology and Genetics
- Course code: Biol 1000
- Professor: Dr. Michael Cardinal-Aucoin
- Semester: Winter 2025
The Eukaryotic Cell
- Eukaryotic cells possess internal membranes creating compartments called organelles.
- Each organelle has a specialized function.
- Examples of organelles
- Nucleus
- Endomembrane system (Endoplasmic reticulum, Golgi apparatus, Lysosomes, Vacuoles)
- Mitochondria
- Chloroplasts
- Peroxisomes
- Cytoskeleton
Eukaryotes
- Plant, animal, and protist cells share most of the same organelles.
- Organelles vary in size, depending on their function.
- Diagram comparing the structure of animal & plant cells
Nucleus
- Nucleus: the most conspicuous organelle in eukaryotes.
- Stores the DNA.
- Nuclear Envelope (a double membrane) surrounds the nucleus.
- Nuclear Pores: gateways for molecules entering and leaving the nucleus.
- Nucleolus: a dense region within the nucleus where rRNA is synthesized.
- Chromatin: DNA organized with proteins (e.g., histones)
- During cell division, chromatin condenses forming chromosomes
More about the Nucleus
- DNA, the genetic material, is organized into chromatin, connected with proteins, for instance, histones.
- During cell division, chromatin thickens to produce distinct structures, chromosomes.
DNA Measurement
- The DNA in a single cell, stretched out end to end, measures roughly 6.5 kilometers.
Nuclear Pore
- Controls traffic in and out of the nucleus.
- A multi-protein complex.
- Specific molecules travel into or out of the nucleus.
- Examples are Ribosomes, messenger RNA (mRNA).
Ribosomes
- Present in both prokaryotes and eukaryotes.
- In eukaryotes, made in the nucleolus.
- Complexes of rRNA and proteins.
- Sites of protein synthesis
- Can be free in the cytoplasm or bound to the endoplasmic reticulum membrane.
Protein Synthesis
- Free ribosomes synthesize proteins for use within the cytosol.
- Membrane-bound ribosomes synthesize proteins destined for secretion or insertion into membranes (e.g., endoplasmic reticulum).
Signal Peptides
- Proteins have signal peptides, guiding them to their appropriate destination.
Proteins Destined for Nucleus
- Proteins meant for the nucleus have a nuclear localization signal (NLS).
Endomembrane System
- Interconnected network of membranes and organelles working together in a regulated fashion.
- Examples of components
- Nuclear envelope
- Endoplasmic reticulum
- Golgi apparatus
- Lysosomes
- Vacuoles
- Plasma membrane
Endoplasmic Reticulum
- Extensive network of membranes.
- Continuous with the nuclear envelope.
- Accounts for more than half of the total membrane in many eukaryotic cells.
- Two distinct regions (rough ER, smooth ER) differing in structure and function.
Rough ER
- Flattened sacs (cisternae) studded with ribosomes.
- Synthesizes proteins to be secreted.
- Synthesizes membrane components
Smooth ER
- Network of tubules.
- Lacks ribosomes.
- Involved in various metabolic processes (e.g., lipid synthesis, metabolism of carbohydrates, detoxification).
- Storage of calcium ions.
Golgi Apparatus
- Looks like flattened membrane sacs (cisternae).
- Not physically continuous with the endoplasmic reticulum(ER).
- Processing center for proteins and lipids.
- Modifies proteins and lipids produced by the endoplasmic reticulum
- Synthesizes carbohydrates.
- Sorts proteins to proper destinations (e.g., different membranes).
Lysosomes
- Specialized vesicles derived from the Golgi body.
- Contain hydrolytic enzymes.
- Digest damaged or unneeded macromolecules.
- Maintain an acidic environment.
- Not present in plant cells.
- Involved in various aspects of cellular homeostasis through different processes (e.g., autophagy, phagocytosis).
Vacuoles
- Large vesicles derived from the endoplasmic reticulum and Golgi apparatus.
- Various functions.
- Food vacuoles: store food
- Digestive vacuoles: act like lysosomes in plants
- Contractile vacuoles: expel water from cells
- Central vacuoles: (in many plant cells) regulate turgor pressure.
Mitochondria
- Sites of cellular respiration.
- Generate ATP (chemical energy) from sugars, fats, and other fuels
- Single or numerous, depending on cell needs.
- Enclosed by two membranes (outer and inner):
- Inner membrane is highly folded, forming cristae.
- Mitochondrial matrix: space inside the inner membrane, containing enzymes, mitochondrial DNA, and ribosomes.
- Membranes and matrix divide the cell into functional compartments.
Chloroplasts
- Capture light energy for photosynthesis (synthesizing sugars from CO2).
- Have an outer and inner membrane, thylakoids inside.
- Thylakoids organize light-capturing pigments.
- Stroma: space containing chloroplast DNA, ribosomes, and enzymes necessary for photosynthesis.
Origins of Mitochondria and Chloroplasts (Endosymbiosis)
- Mitochondria and chloroplasts evolved from prokaryotes engulfed by ancestral eukaryotic cells.
- Evidence for endosymbiotic theory: size similar to bacteria, their double layered membrane, and the fact that they possess their own DNA.
Peroxisomes
- Specialized metabolic compartments bound by a single membrane.
- Involved in various metabolic processes (e.g., breakdown of fatty acids, detoxification of harmful molecules).
- Produce hydrogen peroxide which is quickly broken down by an enzyme called catalase to water and oxygen.
Endomembrane System: Examples (Insulin Synthesis)
- Insulin: a peptide hormone produced by the pancreatic beta cells.
- Insulin synthesis occurs in the secretory pathway where proteins are synthesized, tagged with signals for proper destination then modified by other parts of the endomembrane system.
Other Information:
- The endomembrane system plays a vital role in various cellular processes, including protein and lipid synthesis, secretion, and material degradation.
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Description
Test your knowledge on organelles found in eukaryotic cells with this quiz. Questions cover key functions and distinctions among various organelles, including the endoplasmic reticulum, Golgi apparatus, and cytoskeleton. Challenge yourself to identify the components and roles of these essential cell structures.