Lecture 1 Flashcards
State nine properties of cells
Here are some difficult MCQs assessing the properties of cells:
A) Highly Complex and Organized
B) Evolve
C) Can Reproduce Themselves
D) Carry Out Chemical Reactions
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### 2. Which property is primarily associated with the cellular ability to maintain internal conditions and respond to changes in their environment?
A) Acquire and Utilize Energy
B) Highly Complex and Organized
C) Are Capable of Self Regulation
D) Possess a Genetic Program and the Means to Use It
**s.*
A) Carry Out Mechanical Activities
B) Acquire and Utilize Energy
C) Evolve
D) Respond to Stimuli
.*
A) Carry Out Chemical Reactions
B) Possess a Genetic Program and the Means to Use It
C) Evolve
D) Highly Complex and Organized
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### 5. Which property is essential for cells to adapt to environmental changes and survive in varying conditions?
A) Highly Complex and Organized
B) Respond to Stimuli
C) Carry Out Mechanical Activities
D) Evolve
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### 6. Which property allows cells to undergo genetic variations and adaptation over generations?
A) Carry Out Chemical Reactions
B) Evolve
C) Acquire and Utilize Energy
D) Can Reproduce Themselves
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### 7. Which of the following is not a typical characteristic of cells?
A) Carry Out Mechanical Activities
B) Evolve
C) Acquire and Utilize Energy
D) Non-specific Response to External Factors
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### 8. Which property of cells is directly involved in the formation of cellular structures and movement?
A) Highly Complex and Organized
B) Carry Out Mechanical Activities
C) Possess a Genetic Program and the Means to Use It
D) Are Capable of Self Regulation
**.*
A) Highly Complex and Organized
B) Carry Out Chemical Reactions
C) Are Capable of Self Regulation
D) Evolve
** Here are MCQs designed to test your ability to determine which options are properties specific to cells:
A) Ability to reproduce through binary fission or mitosis
B) Ability to exhibit seasonal migration
C) Ability to undergo ecological succession
D) Ability to perform photosynthesis in the atmosphere
**
### 2. Which of the following properties is specific to cellular structures?
A) Ability to exhibit symbiosis
B) Ability to engage in energy transformation through metabolic pathways
C) Ability to migrate in response to environmental stimuli
D) Ability to participate in genetic drift
*
A) Ability to form ecosystems
B) Ability to maintain homeostasis at the cellular level
C) Ability to display learned behaviors
D) Ability to evolve through natural selection
**
### 4. Which of the following is a defining feature of cells rather than of multicellular organisms or ecological systems?
A) Ability to undergo meiosis
B) Ability to communicate through pheromones
C) Ability to regulate tissue growth
D) Ability to form complex social structures
**
A) Ability to form and maintain organ systems
B) Ability to undergo cellular respiration
C) Ability to exhibit complex behaviors
D) Ability to influence climate change
**
A) Ability to divide and form new cells
B) Ability to evolve populations over generations
C) Ability to interact with other species in an ecosystem
D) Ability to regulate whole-organism homeostasis
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### 7. Which of these options describes a property specific to cellular function?
A) Ability to adapt to ecological niches
B) Ability to synthesize proteins based on genetic information
C) Ability to migrate in response to environmental changes
D) Ability to form symbiotic relationships
**
1.Highly Complex and Organized
2.Acquire and Utilize Energy
3.Possess a Genetic Program and the Means to Use It
4.Can Reproduce
Themselves
5.Evolve
6.Carry Out Chemical Reactions
7.Are Capable of Self Regulation
8.Carry Out Mechanical
Activities
9.Respond to Stimuli
Here are some difficult MCQs assessing the properties of cells:
A) Highly Complex and Organized
B) Evolve
C) Can Reproduce Themselves
D) Carry Out Chemical Reactions
Answer: C) Can Reproduce Themselves
Explanation: While other properties can apply to biological systems broadly, the ability to reproduce themselves is specific to cells.
A) Acquire and Utilize Energy
B) Highly Complex and Organized
C) Are Capable of Self Regulation
D) Possess a Genetic Program and the Means to Use It
Answer: C) Are Capable of Self Regulation
Explanation: Self-regulation involves maintaining internal conditions and responding to environmental changes, which is specific to cells.
A) Carry Out Mechanical Activities
B) Acquire and Utilize Energy
C) Evolve
D) Respond to Stimuli
Answer: B) Acquire and Utilize Energy
Explanation: This property involves metabolic activities and energy transformations, a fundamental characteristic of cells.
A) Carry Out Chemical Reactions
B) Possess a Genetic Program and the Means to Use It
C) Evolve
D) Highly Complex and Organized
Answer: B) Possess a Genetic Program and the Means to Use It
Explanation: This property refers to the cell’s ability to use its genetic code to guide the synthesis of proteins and other essential molecules.
A) Highly Complex and Organized
B) Respond to Stimuli
C) Carry Out Mechanical Activities
D) Evolve
Answer: B) Respond to Stimuli
Explanation: Cells must be able to detect and respond to changes in their environment to survive and adapt.
A) Carry Out Chemical Reactions
B) Evolve
C) Acquire and Utilize Energy
D) Can Reproduce Themselves
Answer: B) Evolve
Explanation: Evolution involves genetic changes and adaptation over generations, a property specific to living organisms including cells.
A) Carry Out Mechanical Activities
B) Evolve
C) Acquire and Utilize Energy
D) Non-specific Response to External Factors
Answer: D) Non-specific Response to External Factors
Explanation: Cells typically have specific responses to external stimuli rather than non-specific responses.
A) Highly Complex and Organized
B) Carry Out Mechanical Activities
C) Possess a Genetic Program and the Means to Use It
D) Are Capable of Self Regulation
Answer: B) Carry Out Mechanical Activities
Explanation: Mechanical activities such as movement and structural formation are specific to cellular functions.
A) Highly Complex and Organized
B) Carry Out Chemical Reactions
C) Are Capable of Self Regulation
D) Evolve
Answer: C) Are Capable of Self Regulation
Explanation: Self-regulation allows cells to maintain internal stability and function despite external fluctuations.
Here are MCQs designed to test your ability to determine which options are properties specific to cells:
A) Ability to reproduce through binary fission or mitosis
B) Ability to exhibit seasonal migration
C) Ability to undergo ecological succession
D) Ability to perform photosynthesis in the atmosphere
Answer: A) Ability to reproduce through binary fission or mitosis
Explanation: Reproduction through binary fission or mitosis is a fundamental property of cells.
A) Ability to exhibit symbiosis
B) Ability to engage in energy transformation through metabolic pathways
C) Ability to migrate in response to environmental stimuli
D) Ability to participate in genetic drift
Answer: B) Ability to engage in energy transformation through metabolic pathways
Explanation: Cells engage in energy transformation through metabolic pathways, a core cellular function.
A) Ability to form ecosystems
B) Ability to maintain homeostasis at the cellular level
C) Ability to display learned behaviors
D) Ability to evolve through natural selection
Answer: B) Ability to maintain homeostasis at the cellular level
Explanation: Maintaining homeostasis at the cellular level is a unique property of cells.
A) Ability to undergo meiosis
B) Ability to communicate through pheromones
C) Ability to regulate tissue growth
D) Ability to form complex social structures
Answer: A) Ability to undergo meiosis
Explanation: Meiosis is a process specific to cells, particularly in reproduction.
A) Ability to form and maintain organ systems
B) Ability to undergo cellular respiration
C) Ability to exhibit complex behaviors
D) Ability to influence climate change
Answer: B) Ability to undergo cellular respiration
Explanation: Cellular respiration is a fundamental process occurring within individual cells.
A) Ability to divide and form new cells
B) Ability to evolve populations over generations
C) Ability to interact with other species in an ecosystem
D) Ability to regulate whole-organism homeostasis
Answer: A) Ability to divide and form new cells
Explanation: Cell division is a property specific to cells, though it contributes to overall organismal growth.
A) Ability to adapt to ecological niches
B) Ability to synthesize proteins based on genetic information
C) Ability to migrate in response to environmental changes
D) Ability to form symbiotic relationships
Answer: B) Ability to synthesize proteins based on genetic information
Explanation: Protein synthesis based on genetic information is a fundamental cellular function.
These questions will help you identify which characteristics are intrinsic to cells versus those that may apply to broader biological contexts.
State the characteristics of prokaryotic cells(prokaryotes are bacteria and archaea cells)
Cell wall
•Peptidoglycan cell wall in bacteria and pseudopeptidoglycan cell wall in archaea
•Gives shape, protects against environment and dehydration
Nucleoid region
•single Circular chromosome containing genetic material(DNA)(the DNA in eukaryotes are straight not circular )
•Non-membrane bound so they don’t have a membrane bound nucleus. Their genetic material is in the nucleoid or nucleoid region. Some prokaryotes have DNA fragments called plasmids. Yes, a bacterium can have both a nucleoid and plasmids. The nucleoid is the region within the cell where the main bacterial chromosome, typically a single circular DNA molecule, is located. This chromosome contains the essential genetic information necessary for the bacterium’s growth, reproduction, and basic functions.
Plasmids, on the other hand, are smaller, circular DNA molecules that exist independently of the chromosomal DNA. They often carry additional genes that can provide the bacterium with advantageous traits, such as antibiotic resistance, virulence factors, or the ability to metabolize unusual substances. Plasmids can be transferred between bacteria through processes such as conjugation, thereby spreading these beneficial traits within bacterial populations.
Flagellum
•For movement
Pilus
•Conjugation (exchange of nuclear material)
Fimbria
•Attachment to surfaces
Ribosomes
•Protein synthesis from mRNA
•70S made up of 2 subunits (50S and 30S)
.they don’t have membrane bound organelles. All their cellular processes occur in the cytoplasm or cell membrane
State four characteristics of eukaryotes (fungi,animals,protists(protists include amoeba,paramecium,plasmodium,giardia lamblia,helminths)
State three differences between prokaryotes and eukaryotes
Are viruses and prions prokaryotes or eukaryotes or neither?
Give the two main types of prokaryotes
Larger than prokaryotic cells
•Have no capsule or cell wall. Note: some protists and fungi have capsule or cell wall even though eukaryotes don’t have cell wall.
•Nuclear material bound in membrane called nucleus
•Possesses no pilus, fimbria or flagella
•Membrane bound organelles
Differences Between Protists (Eukaryotes) and Prokaryotes:prokaryotes include bacteria and viruses.
1. Cell Structure: • Protists (Eukaryotes): Have a true nucleus enclosed by a nuclear membrane and possess membrane-bound organelles (e.g., mitochondria, endoplasmic reticulum). • Prokaryotes: Lack a true nucleus; their genetic material is located in a nucleoid region. They do not have membrane-bound organelles. 2. Genetic Material: • Protists (Eukaryotes): Their DNA is linear and organized into chromosomes within the nucleus. • Prokaryotes: Their DNA is usually circular and found in the cytoplasm without a surrounding membrane. 3. Cell Size: • Protists (Eukaryotes): Typically larger, ranging from 10 to 100 micrometers. • Prokaryotes: Generally smaller, usually around 1 to 10 micrometers. 4. Reproduction: • Protists (Eukaryotes): Reproduce by mitosis and meiosis; can have complex life cycles. • Prokaryotes: Reproduce asexually through binary fission;
Prokaryotes:
1. Bacteria: • Single-celled organisms that lack a true nucleus and membrane-bound organelles. • Examples: Escherichia coli (E. coli), Staphylococcus aureus, Bacillus anthracis. 2. Archaea: • Another group of single-celled organisms similar to bacteria in structure but genetically distinct. • Often found in extreme environments (e.g., hot springs, deep-sea vents). • Examples: Halobacterium (found in salty environments), Thermoplasma (found in hot, acidic environments).
Non-Prokaryotic Entities:
1. Viruses: • Not considered living organisms, and not classified as prokaryotes or eukaryotes. • They consist of genetic material (DNA or RNA) enclosed in a protein coat and require a host cell to replicate. • Examples: HIV, influenza virus, SARS-CoV-2. 2. Prions: • Misfolded proteins that can cause other proteins to misfold, leading to disease. • Not classified as living organisms, and not considered prokaryotic or eukaryotic
What are the components of the plasma membrane?
What is its main function?
How does it carry out its main function?
State two other functions
Composition:
1.Phospholipids (bilayer)
2.Proteins (cell recognition, transport, signalling)
3.Cholesterol
4.Others (carbohydrates, other lipids)
Function:
The main function of the plasma membrane is that it acts as a physical barrier between the external environment and the inner cell organelles.
How does it perform its main function?
The plasma membrane is a selectively permeable membrane, which permits the movement of only certain molecules both in and out of the cell.
Other functions:
The plasma membranes also play an important role in both the endocytosis and exocytosis processes.
The plasma membrane also functions by facilitating communication and signalling between the cells.
Here’s how the plasma membrane facilitates endocytosis, exocytosis, and cell communication:
-
Endocytosis and Exocytosis:
- Endocytosis: The plasma membrane engulfs external substances, forming a vesicle that brings the materials into the cell. This process can be specific (e.g., receptor-mediated endocytosis) or non-specific.
- Exocytosis: The plasma membrane expels materials from the cell. Vesicles containing the substances fuse with the membrane, releasing their contents outside the cell. This is crucial for processes like neurotransmitter release and hormone secretion.
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Communication and Signaling:
- Receptors: Integral membrane proteins act as receptors that bind to specific signaling molecules (ligands), such as hormones or neurotransmitters. This binding triggers a cascade of intracellular events.
- Signal Transduction: Once a ligand binds to a receptor, it can initiate signal transduction pathways that alter cellular activities. This process often involves secondary messengers and changes in enzyme activity or gene expression.
- Cell Recognition: Glycoproteins and glycolipids on the membrane surface facilitate cell recognition and interaction, which is important for immune responses and tissue formation.
These functions allow cells to interact with their environment, take in necessary substances, expel waste, and communicate with other cells.
Fungi and protists don’t have cell wall but some do. Give examples of the ones that do
While most eukaryotic cells do not have cell walls, many protists and fungi do. Here are examples of protists and fungi that possess cell walls:
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Algae:
- Green Algae: Such as Chlamydomonas and Volvox, which have cell walls made primarily of cellulose.
- Brown Algae: Such as kelp, with cell walls containing alginates.
- Red Algae: Such as Porphyra, which have cell walls containing agar and carrageenan.
- Diatoms: These are a type of algae with cell walls composed of silica, forming intricate and beautiful glass-like structures known as frustules.
- Dinoflagellates: Some species have cell walls made of cellulose plates, which can contribute to their distinctive shapes and structures.
-
Yeasts:
- Saccharomyces cerevisiae (baker’s yeast), which has cell walls composed of glucans and mannoproteins.
-
Molds:
- Aspergillus and Penicillium, with cell walls primarily made of chitin and glucans.
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Mushrooms:
- Agaricus bisporus (common mushroom) and other basidiomycetes, with cell walls made of chitin.
- Protists: Many algae (green, brown, and red algae), diatoms, and some dinoflagellates have cell walls.
- Fungi: Yeasts, molds, and mushrooms all possess cell walls, primarily composed of chitin and other polysaccharides.
These cell walls provide structural support, protection, and help maintain the shape of these organisms, similar to the role of cell walls in plants.
What is the importance of phospholipids structure of the cell membrane?
What is the importance of cholesterol in the cell membrane
What is the importance of protein transporters for the cell membrane?
What is the importance of the semi permeable membrane
Why can’t potassium enter the cell anyhow it wants? What does it need to enter?
Phospholipids structure in the plasma membrane helps the cell exist in its aqueous environment.
Phospho or phosphate group binds to a glycerol molecule. The glycerol molecule is bound to two fatty acids(they’re hydrophobic)
Phosphate groups (they’re hydrophilic. Hydrophilic heads) face outward and fatty acids face inwards (they’re hydrophobic. Hydrophobic tails) so they don’t come into contact with the water in the cell
Cholesterol gives rigidity to the cell membrane. Cholesterol contributes to the rigidity of the cell membrane. It helps to stabilize the membrane’s structure and reduce its fluidity, making it less permeable to small water-soluble molecules. So cholesterol doesn’t make the cell fluid
Protein transporters help transport molecules
Integral proteins can serve as transporters
Glycoprotein(sugar and protein)
Glycolipids(sugar and lipids)
Endocytosis and exocytosis
Semi permeable membrane:
Allows Uncharged or hydrophobic molecules enter into the cell
Does not allow Potassium and other molecules to just enter the cell unless they use transport proteins cuz they are charged molecules
Your summary is mostly correct, but here are some clarifications:
- Integral Proteins: These proteins span the cell membrane and can function as transporters, channels, or receptors. They help move molecules across the membrane, including those that cannot diffuse freely.
- Glycoproteins: These are proteins with carbohydrate groups attached. They are involved in cell recognition and communication.
- Glycolipids: These are lipids with carbohydrate groups attached. They also play a role in cell recognition and stability of the membrane.
-
Semi-Permeable Membrane: This type of membrane allows certain molecules to pass through while blocking others.
- Uncharged or Hydrophobic Molecules: These can diffuse through the membrane more easily.
- Charged Molecules: Like potassium ions (K+), which cannot easily pass through the hydrophobic core of the membrane, typically require specific transport proteins or channels to cross the membrane.
State the three main parts of the nucleus
Which structure in the nucleus has a double membrane ?
What is the function of nuclear pores?
What is chromatin
What is the importance of the nucleolus
Main parts of nucleus: nucleolus, nucleoplasm and genetic material
nuclear envelope is a double-membrane structure that constitutes the nucleus’ outermost portion
The nuclear pores control the passage of ions, molecules, and RNA between the nucleoplasm and cytoplasm.
•Chromatin describes the material that makes up the chromosomes both when condensed and decondensed.
•The Nucleolus assembles individual parts of the ribosomes to synthesis the complete ribosomes
In MCQ settings, the main parts of the nucleus typically include:
- Nucleolus: The site of ribosomal RNA synthesis and ribosome assembly.
- Nucleoplasm: The substance within the nucleus that supports the nuclear components.
- Nuclear Envelope: The double membrane that encloses the nucleus, separating it from the cytoplasm. It includes nuclear pores that regulate the movement of molecules between the nucleus and cytoplasm.
The genetic material (DNA and chromatin) is often considered part of the nuclear contents rather than a separate structural component, but it’s crucial to mention in the context of nuclear function and organization.
What is the importance of mitochondria ?
Which part of the mitochondria folds inward to form cristae?
Mitochondria has its own ribosomes and DNa true or false?
Mitochondria makes ATP from what two main reduced equivalents?
Electron transport and oxidative phosphorylation occur in which part of the mitochondria?
Citric acid cycle ,fatty acid oxidation and initial steps of heme synthesis occur in which part of the mitochondria
Powerhouses” or “energy factories”. Responsible for making adenosine triphosphate (ATP), the cell’s main energy-carrying molecule.
•From reduced equivalents (FADH2 and NADH)
•Possess their own ribosomes and DNA.
Protein synthesis
Mitochondrion- has dna,ribosomes, inner and other membrane
It receives electrons from FADH to NADH. Passes them thru electron transport chain, generate protons which reenter the inner membrane of mitochondria to generate Atp
The mitochondrial matrix is the space enclosed by the inner membrane of the mitochondrion. It contains the mitochondria’s own DNA, ribosomes, and various enzymes involved in metabolic processes such as the citric acid cycle (Krebs cycle).
To summarize the main parts of the mitochondrion:
- Outer Membrane: The lipid bilayer that encloses the entire organelle.
- Inner Membrane: The lipid bilayer that folds inward to form structures called cristae, which increase the surface area for energy production.
- Matrix: The space inside the inner membrane, where metabolic activities occur.
- Intermembrane Space: The space between the outer and inner membranes.
Electron transport, oxidative phosphorylation occur in the inner membrane of the mitochondria
Inner Mitochondrial Membrane:
- Electron Transport Chain (ETC)
- ATP Synthesis (Oxidative Phosphorylation)
Mitochondrial Matrix:
- Krebs Cycle (Citric Acid Cycle)
- Heme Synthesis (initial steps)
- Fatty Acid Oxidation
- Amino Acid Metabolism (partially)
In the endomembrane system What are the functions of the endoplasmic reticulum and smooth endoplasmic reticulum ?
What gives the rough endoplasmic reticulum its rough appearance and what is the function of this thing?
What are the difference sim the functions of the ER and the Golgi apparatus
ER is responsible for manufacture and folding of proteins.
Smooth ER- cholesterol and other lipids
Rough endoplasmic reticulum-Membranes of these structures are lined withribosomeson their outer surfaces, giving them a rough appearance
The ribosomes on the rough endoplasmic reticulum manufactureproteinswhich enter the channels of the endoplasmic reticulum
Smooth endoplasmic reticulum-Plays a major role in synthesizinglipidsby means of enzymes embedded in these smooth membranes
it produces thephospholipidsandcholesterolused in membrane formation, and along with the membrane proteins
While both the endoplasmic reticulum (ER) and Golgi apparatus are involved in processing proteins and lipids, their roles differ in focus and timing:
-
Endoplasmic Reticulum (ER):
- Synthesis and Folding: The rough ER is involved in the synthesis of proteins, particularly those that are to be secreted, incorporated into the plasma membrane, or sent to lysosomes. It also helps in folding proteins and adding modifications like glycosylation.
- Quality Control: The ER monitors the quality of newly synthesized proteins. Misfolded proteins are usually retained and directed to the cytoplasm for degradation (ER-associated degradation or ERAD).
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Golgi Apparatus:
- Processing and Modification: After proteins and lipids leave the ER in transport vesicles, they arrive at the Golgi apparatus. Here, they undergo further modifications, including additional glycosylation, phosphorylation, and sulfation.
- Sorting and Packaging: The Golgi apparatus sorts and packages proteins and lipids into vesicles that are then directed to their appropriate destinations, such as the plasma membrane, lysosomes, or secretion outside the cell.
In summary, the ER is primarily involved in the initial synthesis and quality control of proteins, while the Golgi apparatus is responsible for the final modifications, sorting, and distribution of these molecules.
What is the function of the smooth ER in the liver cells?
What are the functions of the Golgi apparatus in the endomembrane and system?
What is the function of the lysosome?
Why is the lysosome a membrane bound organelle?
In liver cells the smooth ER contains enzymes for the detoxification of harmful drugs and metabolic by-products
Golgi apparatus
Acts to process and package the macromolecules such asproteinsandlipidsthat are synthesized by the cell
A major function is the modifying, sorting and packaging of proteins for secretion.
It is also involved in the transport of lipids around the cell, and the creation oflysosomes.
Lysosome
Contain digestiveenzymes
The main function of lysosomes is to accomplish digestion of food particles
Lysosomes are membrane bound. They contain toxic things to destroy foreign bodies that have been phagocytosed. If the lysosomes weren’t membrane bound, they would destroy regular cells
Which organelle is the quality control officer of the cell?
What would be the consequence of the dysfunction of this organelle?
Golgi apparatus- cis phase (facing ER) and trans phase(facing plasma membrane).
It is the quality control officer of the cell. If the golgi wasn’t there, there would be improper folding of the proteins and release of poorly formed proteins or substance
The Golgi apparatus indeed has two faces, but its role is more complex than just quality control, and some details in your statement need clarification:
-
Cis and Trans Faces of the Golgi Apparatus:
- Cis Face: This side is oriented towards the endoplasmic reticulum (ER), not necessarily the nucleus. It receives newly synthesized proteins and lipids from the ER.
- Trans Face: This side is oriented towards the plasma membrane. It is responsible for sorting and packaging proteins and lipids into vesicles for transport to their final destinations, such as the plasma membrane, lysosomes, or secretion outside the cell.
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Quality Control in the Cell:
- The endoplasmic reticulum (ER) is primarily responsible for the initial folding of proteins and ensuring they are correctly folded. If proteins are improperly folded, they are typically retained in the ER and may be degraded if they can’t be corrected.
- The Golgi apparatus modifies proteins (e.g., glycosylation, sulfation) and plays a role in ensuring that proteins are properly modified before being sent to their final destination. However, it is not the primary site for folding proteins.
-
What Would Happen Without the Golgi Apparatus:
- Without the Golgi apparatus, cells would struggle to modify, sort, and properly distribute proteins and lipids. However, protein folding issues primarily arise in the ER, not the Golgi. So, the absence of the Golgi would lead to problems with protein modification, sorting, and secretion, rather than folding.
- The Golgi apparatus is crucial for modifying, sorting, and shipping proteins and lipids to their correct locations.
- The ER is the main site for protein folding and quality control. Without the Golgi, proteins wouldn’t be properly modified or sent to the right destinations, but folding problems would mainly originate from the ER.
What are the functions of the CIs and trans Golgi apparatus?
Which is located closer to the ER
Which is away from it
The Golgi apparatus has two main phases: the cis-Golgi network (CGN) and the trans-Golgi network (TGN). The cis-Golgi network is located closer to the endoplasmic reticulum (ER) and receives vesicles containing proteins and lipids from the ER. The trans-Golgi network is located further from the ER and is involved in sorting these proteins and lipids and directing them to their final destinations, either within the cell or for secretion outside the cell.
Actually, the cis face of the Golgi apparatus primarily functions in receiving and processing newly synthesized proteins and lipids from the endoplasmic reticulum (ER).
Here’s a clearer breakdown:
-
Cis Face:
- This is the “receiving” side of the Golgi apparatus.
- Proteins and lipids from the ER arrive here in transport vesicles.
- The cis face doesn’t do the actual packaging; instead, it is more involved in initial processing steps like modifying the proteins and lipids as they enter the Golgi.
-
Trans Face:
- This is the “shipping” side of the Golgi apparatus.
- Here, the processed proteins and lipids are packaged into vesicles.
- These vesicles are then sorted and directed to their final destinations, such as the plasma membrane, lysosomes, or secretory pathways.
In summary, the cis face does not package but rather receives and processes, while the trans face is responsible for the final packaging and sorting.
Explain how the ribosomes work with the Golgi apparatus to get proteins
Ribosomes after producing the proteins, sends it to the ER FOR FOLDING AND THEN SENDS IT TO THE GOLGI APPARATUS FOR CLEAVAGE AND MODIFICATION to make sure the proteins were folded right .
Ribosomes and the Golgi apparatus work together in the process of protein synthesis, modification, and packaging within the cell.
- Protein Synthesis by Ribosomes: Ribosomes are the cellular machinery responsible for protein synthesis. They translate the genetic code from messenger RNA (mRNA) into a specific sequence of amino acids to form a protein.
- Protein Modification in the Endoplasmic Reticulum (ER): Once synthesized, many proteins undergo post-translational modifications in the endoplasmic reticulum (ER). These modifications include folding, glycosylation (addition of sugar molecules), and disulfide bond formation, among others.
- Transport to the Golgi Apparatus: After modification in the ER, proteins are transported to the Golgi apparatus via vesicles. These vesicles bud off from the ER and fuse with the cis-Golgi network (CGN), delivering their cargo of newly synthesized proteins.
- Further Processing in the Golgi Apparatus: Within the Golgi apparatus, proteins undergo further modifications, including glycosylation and proteolytic cleavage. This processing is mediated by various enzymes present within the Golgi compartments.
- Sorting and Packaging: The Golgi apparatus also plays a role in sorting proteins to their appropriate destinations within the cell. Depending on specific signals present in the protein sequence, proteins may be directed to different compartments within the cell, including other organelles or the plasma membrane for secretion.
- Export via Secretory Vesicles: Once fully processed and sorted, proteins are packaged into transport vesicles that bud off from the trans-Golgi network (TGN). These vesicles then move to the cell membrane, where they fuse and release their contents (e.g., proteins) outside the cell through a process called exocytosis.
In summary, ribosomes synthesize proteins, which are then modified in the ER and further processed, sorted, and packaged within the Golgi apparatus before being transported to their final destinations inside or outside the cell.
Or
You are correct that the endoplasmic reticulum (ER) plays a significant role in quality control, but here’s how the process works:
- Ribosomes: Synthesize proteins either free in the cytoplasm or bound to the rough ER. Proteins synthesized on the rough ER are directly inserted into the ER lumen.
- Endoplasmic Reticulum (ER): In the rough ER, proteins undergo folding and initial post-translational modifications. The ER has quality control mechanisms to ensure proteins are correctly folded and assembled. Misfolded proteins are typically retained and targeted for degradation.
- Golgi Apparatus: After the initial processing in the ER, proteins are transported to the Golgi apparatus. The Golgi further modifies, sorts, and packages proteins into vesicles. This includes additional post-translational modifications such as glycosylation and cleavage.
In summary:
- The ER is responsible for initial folding and quality control.
- The Golgi apparatus further modifies and sorts the proteins after they have left the ER.
Which organelles dysfunction will cause a problem with insulin?
Insulin is a protein so a problem with insulin not functioning well could be a Golgi apparatus or ER problem.
So they can put different types or combinations of organelles there and ask you where the insulin problem could be coming from then you pick.
Which of the organelles dominate the liver cells?
Which dominate the smooth muscles? Example to remember this one is for gyming
Which organelle synthesized and converts bile acids in the liver?
Which organelle causes beta oxidation of very long chain fatty acids so they’re broken down into smaller pieces to be sent to the mitochondria for more work to be done on them
Different organelles will dominate different cell types.
Example is the liver which is for detoxyfying bad stuff so it will have high amounts of ER specifically the smooth one.
Peroxisomes too dominate liver cells cuz they synthesize and convert bile acids and release them
Smooth muscles during gyming need a lot of muscle bulk and the msucles need ATP which is produced by mitochondria so in the muscle, there’s a high amount of mitochondria compared to something like the Golgi apparatus. Cuz they don’t produce anything for exporting.
What are Peroxisomes and what are their functions?
Which organelle breaks down fatty acids and amino acids
They have a single bilayer membrane. Peroxisomesare small, round organelles enclosed by single membranes.
They carry out oxidation reactions that break down fatty acids and amino acids.
Functions:
-α-oxidation ofbranched fatty acids such as phytanic acid
-β-oxidation of unbranched very-long-chain and polyunsaturated fatty acids
-biosynthesis of plasmalogens: Plasmalogens are a type of phospholipid found in cell membranes, particularly abundant in the membranes of neurons, myelin sheaths, heart muscle cells, and sperm cells.
-conjugation of cholic acid as part of bile acid synthesis
They have special set of enzymes that let them break down very long chain fatty acids (more than 18 carbon atoms) that the mitochondrion can’t break down
They also synthesize, convert bile acids and releasing them. They will be dominant in the liver cells.
Glyogenesis- building fatty acids from scratch
How do Peroxisomes detoxify poisons that enter the body
They also detoxify many poisons that may enter the body. (Many of these oxidation reactions release hydrogen peroxide, H2O2, which would be damaging to cells; however, when these reactions are confined to peroxisomes, catalase enzymes safely break down the H2O2into oxygen and water.)
Cell cycle and cell division:
If cells don’t go through interphase properly, they will mutate.
what are the three Check points in the cell cycle that the cell checks what has Been produced to see if everything is in the right order and If it’s not, it causes the cell to die
Both G1 and G2 check for DNA damage but they check for different aspects of DNA damage. State those different aspects
. If abnormalities are detected at these checkpoints, the cell may undergo apoptosis (programmed cell death) to prevent the propagation of damaged or abnormal cells. Here are the main checkpoints:
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G1 Checkpoint (Restriction Point):
- Occurs near the end of the G1 phase.
- Checks for cell size, nutrient availability, growth factors, DNA damage, and proper internal signaling.
- If conditions are favorable and DNA is undamaged, the cell proceeds to the S phase to initiate DNA replication. Otherwise, it may enter a quiescent state (G0, G0 is a phase where cells exit the cell cycle and cease to actively divide. ) or undergo apoptosis.
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G2 Checkpoint:
- Occurs at the end of the G2 phase, before entry into mitosis.
- Checks for DNA replication completeness, DNA damage, and proper cell size.
- If DNA replication is complete and undamaged, and cell size is adequate, the cell proceeds to mitosis. Otherwise, it may pause for repair or undergo apoptosis.
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Metaphase Checkpoint:
- Occurs during metaphase of mitosis.
- Ensures that all chromosomes are properly attached to the mitotic spindle and aligned at the metaphase plate.
- If chromosomes are not correctly aligned or attached, the checkpoint delays the onset of anaphase until the issues are resolved, preventing unequal distribution of genetic material.
These checkpoints are crucial for maintaining genomic integrity and preventing the proliferation of damaged or abnormal cells. If the cell detects significant abnormalities or fails to pass these checkpoints, it may undergo programmed cell death (apoptosis) to eliminate the potentially harmful cell.
Both G1 and G2 phases include checkpoints to ensure DNA integrity, but they focus on different aspects of DNA assessment.
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G1 Checkpoint:
- The G1 checkpoint, often referred to as the restriction point, ensures that the cell is ready to proceed to DNA replication. It checks for:
- Nutrient availability: Ensures the cell has the resources needed for DNA replication.
- DNA damage: Assesses if the DNA is intact and free from significant damage before replication begins.
- Growth factors and signals: Determines if external signals are appropriate for cell division.
- The G1 checkpoint, often referred to as the restriction point, ensures that the cell is ready to proceed to DNA replication. It checks for:
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G2 Checkpoint:
- The G2 checkpoint occurs after DNA replication but before mitosis. It checks:
- DNA replication: Ensures that DNA replication is complete and accurate.
- DNA damage: Assesses if there are any errors or damage in the replicated DNA before mitosis.
- Repair mechanisms: Confirms that any damage has been repaired.
- The G2 checkpoint occurs after DNA replication but before mitosis. It checks:
- G1 Phase: Checks for DNA damage and readiness to enter the S phase for DNA replication.
- G2 Phase: Checks for DNA damage and the accuracy of DNA replication before proceeding to mitosis.
