1
Q
a prominent feature in archea is that they can survive
A
in very harsh environments
2
Q
hydrophillic molecules
A
those that posses positive or negative charges or contain relatively large numbers of electronegative oxygen or nitrogen numbers interact easilky with water
3
Q
hydrophobic
A
few if any electronegative atoms and do not interact with watert
4
Q
are hydrocarbons hydrophilic or phobic
A
hydrophobic
5
Q
what do hydrophobic molecules do when they are mixed witrh water
A
spontaneosulyt form clusters minimizing contact between hydrocarbon chains and water molecules
6
Q
membranes provide
A
chemically reactive surfaces and exhibit unique transport functions between extracellular compartments and intracellular
7
Q
cell membranes are ______ and _______ cellular components that are intricately inegrated into all living processes
A
versatile and dynam,ic
8
Q
most biological membranes have the same bazsic structure which is
A
a lipid bilayer composed of phospholipids and other lipid molecules which various proteins are embedded or attached indirectly
9
Q
phospholipids have two features that make them ideally suited to their structural role
A
hydrophilic charged or unchargewd polar group (head group).
and a hydrophobic group composed of two fatty acid chains (tails)
10
Q
there are two classes of membrane proteins
there are two classes of membrane proteins
A
integral and peripheral proteins
11
Q
integral proteins are
A
embedded within the membrane because the amino acid residues in the membrane protion of these proteins have hydrophobic side chains
12
Q
because of there fluid nature of cellular membrane inegral proteinsd can
A
diffuse l;aterally
13
Q
peripheral proteins are
A
not embedded within the membrane
14
Q
peripheral proteins (not embededd within the membrane are attached how
A
either by a covalent bonhdto a lipid molecuyle or by noncovalent interaction with a membrane protein or lipid
15
Q
membrane proteins perform a vareity of functions
A
channels and carrier proteins transport specific ions and molecules
receptor proteins have binding sites for extracelluar ligands to trigger a cellular response
16
Q
each biological membrane is composed of a
A
lipid bilayer into which proteins are inserted or attached indirectly
17
Q
What are supramolecular structures in living organisms?
A
Large functional assemblies formed from multiple molecules held together by noncovalent interactions.
These structures play critical roles in various biological functions.
18
Q
Give examples of supramolecular structures.
A
- Ribosomes
- Sarcomeres in muscle cells
- Proteasomes
These examples illustrate the diversity of supramolecular structures in biological systems.
19
Q
What is the principle of self-assembly?
A
The ability of molecules to spontaneously form stable, functional complexes because they contain inherent structural information.
This principle is fundamental to many biological processes.
20
Q
What molecular features allow self-assembly to occur?
A
- Complementary shapes
- Charge distributions
- Hydrophobic regions
These features enable weak noncovalent interactions that drive self-assembly.
21
Q
What types of interactions stabilize supramolecular complexes?
A
Numerous weak noncovalent interactions (hydrogen bonds, ionic interactions, hydrophobic interactions).
These interactions collectively contribute to the stability of supramolecular structures.
22
Q
How do hydrophilic and hydrophobic interactions contribute to self-assembly?
A
- Hydrophilic groups interact with water
- Hydrophobic groups are excluded from water
This drives proper assembly by promoting favorable interactions.
23
Q
When does self-assembly require assistance?
A
When improper interactions must be prevented, such as during protein folding.
Assistance is crucial to ensure correct structural formation.
24
Q
What are molecular chaperones?
A
Proteins that assist in proper folding by preventing inappropriate interactions during self-assembly.
They play a vital role in maintaining protein integrity.
25
What is **preexisting information** in self-assembly?
The requirement of an existing structure as a template to assemble new structures, such as chromosomes or membranes.
## Footnote
This concept highlights the importance of templates in biological assembly processes.
26
# bio
biologicl membranes are inextricably integrated into
all living processes
27
in organisms the molecules in supramolecular sttructures assemble
spontaneous
28
29
What are **molecular machines** in cells?
Multisubunit complexes that function as physical machines with moving parts that perform work.
## Footnote
They are essential for various cellular tasks.
30
What kind of **work** do molecular machines perform?
Work defined as force applied over a distance, producing directed movement to complete specific cellular tasks.
## Footnote
This includes tasks like transport and assembly within the cell.
31
Why are **molecular machines** necessary in cells?
They enable tasks that would be inefficient or impossible without controlled, directed motion.
## Footnote
This is crucial for maintaining cellular function and organization.
32
How are biological molecular machines similar to **human-made machines**?
Both have moving parts and require energy-transducing mechanisms to convert energy into motion.
## Footnote
This similarity allows for the execution of complex tasks.
33
How are biological machines different from **human-made machines**?
They are built from fragile molecules (mainly proteins) and operate under mild cellular conditions.
## Footnote
This makes them more sensitive to environmental changes.
34
What key feature is shared by all biological **molecular machines**?
Energy-driven changes in the three-dimensional shape of proteins.
## Footnote
This feature is crucial for their functionality.
35
What molecules commonly power **molecular machines**?
Nucleotides such as ATP and GTP.
## Footnote
These molecules provide the necessary energy for movement.
36
What are **motor proteins**?
Protein components of molecular machines that bind and hydrolyze ATP or GTP to generate motion.
## Footnote
They play a critical role in cellular movement and transport.
37
How does **nucleotide hydrolysis** drive movement in molecular machines?
Hydrolysis causes a targeted shape change in the protein, which is transmitted to neighboring subunits.
## Footnote
This mechanism is essential for coordinated movement.
38
Why are **molecular machines** highly efficient?
Nucleotide hydrolysis is essentially irreversible, ensuring one-directional movement.
## Footnote
This efficiency is vital for cellular processes.
39
What is **macromolecular crowding**?
The condition inside cells where high concentrations of macromolecules occupy significant space, limiting available volume.
## Footnote
This phenomenon is crucial for understanding cellular processes.
40
Why is the term **“crowded”** used instead of **“concentrated”**?
Because many different macromolecules are present, each usually in low numbers, but together they occupy a large fraction of the cell.
## Footnote
This highlights the diversity and interaction of macromolecules in cellular environments.
41
What are the typical concentrations of **proteins** inside cells?
Approximately 200–400 mg/mL.
## Footnote
These concentrations contribute to the crowded environment within cells.
42
What is **excluded volume** in cells?
The fraction of cellular volume occupied by macromolecules, typically 20–40%.
## Footnote
This concept is important for understanding how space is utilized within the cell.
43
How does **macromolecular crowding** affect large molecules?
Nonspecific steric repulsion limits the addition and movement of other macromolecules.
## Footnote
This can impact various cellular functions and interactions.
44
How much **intracellular space** is available to small molecules?
Roughly 70% of the cellular volume.
## Footnote
This availability is crucial for the diffusion and interaction of small molecules.
45
Why is **macromolecular crowding** biologically important?
It significantly influences biochemical reaction rates and molecular interactions.
## Footnote
Understanding this can help in studying cellular processes and reactions.
46
Name the **cellular processes** affected by macromolecular crowding.
* Protein folding
* Protein–protein binding
* Chromosome structure
* Gene expression
* Signal transduction
## Footnote
These processes are essential for maintaining cellular function and integrity.
47
each type of living cell has its own charecteristic set of proteins calld
its proteome
48
each living cells proteome constantly
changes in response to environmental conditions
49
following their syntehsis on ribosomes proteins now
must fold into their functional shapes, be transported to their proper destinations and then be promptly degraded when they are damaged
50
what is proteotoxic stress
a condition in which there is a accumlation of misfolded proteins
51
what is proteotoxic stress caused by
genetic variations or environmental insults such as oxidative stress elevated temps and exposure to toxins
52
cells in which protein quality is high are said to be in a state of protein homeostasis or
proteostasis
(homeostasis but proteins)
53
the processes that restore and monitor proteostasis is called the
proteostais networj
54
living organisms require ______ and ______ to create order
living organism require both energy and information to create order
55
the process that organims use to receuver and interoret information is
signal transduction
56
all information processing can be divided into 4 stages
1. reception
2. transduction
3. response
4. termination
57
1. reception is
signal molecule, called ligand, binds to and activates a receptor
58
2 transduction
liigand binding triggers a change in 3d shape of receotir
this results in conversion of primary message to a secondnary message often across a membrane barrier
59
# 3
3 response
once initiated the internal signal cause a signal cascade
result of this involves changes in enzymatuc actvity / gene expression, cytoskeletal arrangement, cell movement, and cell growth or drivision
60
4 termination
use variety of different wayts to terminate the signal
61
living organiusms receiver interpety and respond to environmental information by the means of
signal transduction
62
63
Why is **Ca²⁺** considered a **universal signaling device** in cells?
Cells use transient increases in cytoplasmic Ca²⁺ to respond to a wide variety of external stimuli
## Footnote
Ca²⁺ plays a crucial role in various cellular signaling pathways.
64
What is the **normal resting cytoplasmic Ca²⁺ concentration**?
~100 nM, maintained at low levels
## Footnote
This low concentration is essential for proper cellular function.
65
How do cells keep **cytoplasmic Ca²⁺ levels low** at rest?
* ATP-driven Ca²⁺ pumps in the plasma membrane
* ATP-driven Ca²⁺ pumps in organelle membranes (e.g., ER)
## Footnote
These pumps actively transport Ca²⁺ out of the cytoplasm.
66
How is **calcium signaling** decoded by the cell?
By the amplitude, timing, and localization of brief Ca²⁺ concentration spikes
## Footnote
Different patterns of Ca²⁺ signaling can lead to different cellular responses.
67
What happens when **Ca²⁺ binds** to **Ca²⁺-responsive proteins**?
The proteins change shape and functional properties, triggering specific cellular responses
## Footnote
This binding is crucial for the activation of various cellular processes.
68
Why must **Ca²⁺ release** be tightly regulated?
To prevent nonspecific activation of Ca²⁺-dependent processes
## Footnote
Uncontrolled Ca²⁺ signaling can lead to cellular dysfunction.
69
How do cells prevent **prolonged Ca²⁺ signaling**?
By rapid clearance of Ca²⁺ from the cytoplasm after signaling
## Footnote
This ensures that signaling is brief and specific.
70
List major **cellular processes regulated by Ca²⁺** in animals.
## Footnote
Low Ca²⁺ at rest → brief localized spikes → protein activation → rapid cleanup
* Neurotransmitter release
* Hormone secretion
* Protein folding
* Muscle contraction
## Footnote
Ca²⁺ is involved in many critical physiological functions.
71
How does **Ca²⁺ trigger insulin secretion**?
Elevated blood glucose increases Ca²⁺ near the β-cell membrane, triggering vesicle fusion and insulin release
## Footnote
This process is vital for glucose homeostasis.
72
What is **exocytosis**?
Ca²⁺-dependent fusion of secretory vesicles with the plasma membrane to release their contents
| Low Ca²⁺ at rest → brief localized spikes → protein activation → rapid c
## Footnote
Exocytosis is essential for the secretion of hormones and neurotransmitters.
73
74
What are the typical **shapes of prokaryotic cells**?
* Rod-shaped (bacilli)
* Spherical (cocci)
* Spiral-shaped (spirilla)
## Footnote
These shapes are fundamental characteristics used to classify bacteria.
75
What is the typical **size of a prokaryotic cell**?
About 1 μm in diameter and 2 μm in length
## Footnote
This size range is typical for most prokaryotic cells.
76
What **structural features** are common to most prokaryotes?
* Cell wall
* Plasma membrane
* Circular DNA
* No membrane-enclosed organelles
## Footnote
These features distinguish prokaryotes from eukaryotic cells.
77
What is the function of the **prokaryotic cell wall**?
Maintains cell shape and protects against mechanical injury
## Footnote
The cell wall is crucial for the structural integrity of prokaryotic cells.
78
What gives the **bacterial cell wall** its strength?
Peptidoglycan, a polymer of carbohydrate chains cross-linked by short peptides
## Footnote
Peptidoglycan is a unique component found in bacterial cell walls.
79
What determines **Gram staining properties** of bacteria?
Thickness and chemical composition of the cell wall and associated structures
## Footnote
Gram staining is a critical method for classifying bacteria.
80
What characterizes **Gram-negative bacteria**?
Thin peptidoglycan layer located between the plasma membrane and outer membrane
## Footnote
This structural feature is key to their classification.
81
What is the **outer membrane** of Gram-negative bacteria made of?
Lipopolysaccharide (LPS) instead of phospholipids
## Footnote
LPS plays a significant role in the pathogenicity of Gram-negative bacteria.
82
What is **lipopolysaccharide (LPS)** and why is it important?
A membrane component that acts as an endotoxin causing fever and shock when released
## Footnote
LPS is a critical factor in the immune response to Gram-negative infections.
83
What are **porins**?
Channel proteins in the outer membrane that allow small molecules to pass through
## Footnote
Porins facilitate the transport of nutrients and waste products.
84
What is the **periplasmic space**?
The region between the outer membrane and plasma membrane containing peptidoglycan and enzymes
## Footnote
This space is involved in various metabolic processes.
85
What functions occur in the **periplasmic space**?
* Nutrient digestion
* Transport
* Chemotaxis
## Footnote
These functions are essential for bacterial survival and adaptation.
86
What is the **glycocalyx**?
A layer of polysaccharides and/or proteins secreted outside the cell wall
## Footnote
The glycocalyx can play roles in protection and adherence.
87
What is the difference between a **capsule and a slime layer**?
* Capsules: organized, aid in immune evasion
* Slime layers: disorganized biofilms
## Footnote
Both structures contribute to bacterial virulence.
88
Why are **biofilms** medically important?
They protect bacteria from immune attack and antibiotics
## Footnote
Biofilms can complicate treatment of infections.
89
What is the structure of the **bacterial plasma membrane**?
A phospholipid bilayer reinforced by hopanoids
## Footnote
The plasma membrane is crucial for maintaining cellular integrity.
90
What are **hopanoids** and their function?
Sterol-like molecules that stiffen bacterial membranes
## Footnote
Hopanoids contribute to membrane stability.
91
What are the main functions of the **plasma membrane**?
* Selective permeability
* Nutrient sensing
* Transport
* Energy transduction
## Footnote
These functions are vital for cellular homeostasis.
92
What is the **nucleoid**?
An irregular region containing the bacterial chromosome
## Footnote
The nucleoid is not membrane-bound, distinguishing it from eukaryotic nuclei.
93
What type of **DNA** is found in prokaryotes?
A single, circular chromosome
## Footnote
This structure is essential for prokaryotic genetic organization.
94
What are **plasmids**?
Small circular DNA molecules that replicate independently and provide selective advantages
## Footnote
Plasmids often carry genes for antibiotic resistance.
95
Why are **plasmids** important clinically?
They often carry antibiotic resistance genes
## Footnote
This makes them significant in the context of treating bacterial infections.
96
What are **inclusion bodies**?
Cytoplasmic granules used for storage of nutrients or specialized compounds
## Footnote
Inclusion bodies can store various substances essential for bacterial metabolism.
97
Examples of substances stored in **inclusion bodies**
* Glycogen
* Poly-β-hydroxybutyrate
* Polyphosphate
* Sulfur
* Magnetite
## Footnote
These stored substances can be utilized during nutrient scarcity.
98
What are **magnetosomes** and their function?
Magnetite-containing inclusions that help bacteria orient using Earth’s magnetic field
## Footnote
Magnetosomes are important for navigation in aquatic environments.
99
What fills most of the **prokaryotic cytoplasm**?
* Ribosomes
* Macromolecules
* Metabolites
## Footnote
The cytoplasm is the site of many metabolic processes.
100
What are **ribosomes**?
RNA–protein complexes that synthesize polypeptides
## Footnote
Ribosomes are essential for protein synthesis in all living cells.
101
What are **pili** and their function?
Hair-like structures used for attachment and genetic transfer
## Footnote
Pili play a role in bacterial conjugation and adherence to surfaces.
102
What is **conjugation**?
Transfer of genetic material between bacteria via sex pili
## Footnote
Conjugation is a key mechanism for genetic diversity in bacteria.
103
What is the structure and function of **bacterial flagella**?
Corkscrew-shaped protein filaments used for motility
## Footnote
Flagella enable bacteria to move toward or away from stimuli.
104
How does **flagellar rotation** affect bacterial movement?
* Counterclockwise = forward movement
* Clockwise = stop-and-tumble
## Footnote
This mechanism is crucial for bacterial navigation.
105
How is **flagellar motion powered**?
Motor proteins convert chemical energy into rotational motion
## Footnote
This energy conversion is essential for bacterial motility.
106
How do **eukaryotic cells** differ structurally from **prokaryotic cells**?
* Larger (10–100 μm)
* Contain membrane-bound organelles
* Greater internal compartmentalization
## Footnote
These structural differences contribute to the complexity and functionality of eukaryotic cells.
107
Why does **compartmentalization** increase cellular efficiency?
* Allows high local enzyme concentrations
* Independent regulation of biochemical processes
## Footnote
Compartmentalization enables specialized environments for various cellular functions.
108
What is the **endomembrane system**?
An interconnected network of membranes including:
* Plasma membrane
* ER
* Golgi apparatus
* Lysosomes
* Nucleus
## Footnote
This system plays a crucial role in the synthesis and transport of proteins and lipids.
109
What is the function of **transport vesicles**?
To move molecules between organelles and to/from the plasma membrane
## Footnote
Transport vesicles are essential for intracellular communication and material exchange.
110
What **non-membranous structures** are found in eukaryotic cells?
* Ribosomes
* Cytoskeleton
## Footnote
These structures play vital roles in protein synthesis and maintaining cell shape.
111
What is the **cytoskeleton**?
A dynamic network of filaments that provides:
* Shape
* Support
* Directed intracellular movement
## Footnote
The cytoskeleton is crucial for cell motility and structural integrity.
112
What is the basic structure of the **plasma membrane**?
A lipid bilayer containing:
* Integral proteins
* Peripheral proteins
## Footnote
The plasma membrane is fundamental for maintaining cellular integrity and regulating transport.
113
What are the major functions of the **plasma membrane**?
* Selective permeability
* Signal reception
* Mechanical support
## Footnote
These functions are essential for cell communication and homeostasis.
114
What is the **glycocalyx** in eukaryotic cells?
A carbohydrate coat on the extracellular surface involved in:
* Cell recognition
* Adhesion
* Immune identity
## Footnote
The glycocalyx plays a key role in cell signaling and protection.
115
How are **blood group antigens** related to the glycocalyx?
They are carbohydrate structures that function in self-identity
## Footnote
Blood group antigens are critical for immune recognition.
116
What is the **extracellular matrix (ECM)**?
A gel-like material secreted by fibroblasts that:
* Supports cells
* Regulates signaling
## Footnote
The ECM is important for tissue structure and function.
117
What is the **membrane skeleton**?
A protein meshwork (actin, spectrin) reinforcing the inner surface of the plasma membrane
## Footnote
The membrane skeleton provides mechanical support and helps maintain cell shape.
118
What is the **endoplasmic reticulum (ER)**?
A membrane network involved in:
* Protein synthesis
* Lipid synthesis
* Ca²⁺ storage
## Footnote
The ER is essential for the synthesis and processing of biomolecules.
119
What is the **ER lumen (cisternal space)**?
The internal compartment enclosed by ER membranes, separate from cytoplasm
## Footnote
The lumen is where protein folding and modifications occur.
120
Why is **rough ER** called 'rough'?
Ribosomes are attached to its cytoplasmic surface
## Footnote
This characteristic is crucial for its role in protein synthesis.
121
What types of proteins are processed in the **RER**?
* Membrane proteins
* Proteins destined for secretion or organelles
## Footnote
The RER is key for synthesizing proteins that function outside the cytosol.
122
What happens to proteins as they enter the **RER**?
* Fold
* Undergo glycosylation
* Interact with molecular chaperones
## Footnote
These processes are vital for proper protein function.
123
What is **ER stress**?
Accumulation of misfolded proteins in the ER
## Footnote
ER stress can lead to cellular dysfunction if not resolved.
124
What is **ER-associated degradation (ERAD)**?
Transport of misfolded proteins to the cytoplasm for proteasomal degradation
## Footnote
ERAD is a critical quality control mechanism in the cell.
125
What is the **unfolded protein response (UPR)**?
A stress response that:
* Reduces protein synthesis
* Increases chaperone production
## Footnote
The UPR helps restore normal function during stress.
126
What happens if **ER stress** cannot be resolved?
Autophagy or apoptosis is initiated
## Footnote
This is a protective mechanism to eliminate damaged cells.
127
What distinguishes **smooth ER** from rough ER?
SER lacks ribosomes
## Footnote
This absence is related to its different functions.
128
What are the main functions of **SER**?
* Lipid synthesis
* Detoxification
* Ca²⁺ storage
## Footnote
SER plays a crucial role in metabolic processes.
129
What is the **sarcoplasmic reticulum**?
Specialized SER in muscle cells that stores Ca²⁺ for contraction
## Footnote
This structure is essential for muscle function.
130
What is the **transitional ER (tER)**?
ER subdomain where transport vesicles form
## Footnote
The tER is critical for the movement of proteins to the Golgi.
131
What is **COPII** and its function?
A vesicle coat protein that directs transport from ER to Golgi
## Footnote
COPII is essential for anterograde transport.
132
What is **COPI** and its function?
Vesicle coat protein involved in retrograde transport back to the ER
## Footnote
COPI is important for recycling proteins.
133
What is the structure of the **Golgi apparatus**?
Stacked, flattened membranous sacs (cisternae)
## Footnote
The Golgi apparatus is crucial for processing and sorting proteins.
134
What are the main functions of the **Golgi**?
* Protein modification
* Lipid modification
* Sorting
* Packaging
## Footnote
The Golgi apparatus is key for preparing proteins for their final destinations.
135
What types of modifications occur in the **Golgi**?
* Glycosylation
* Sulfation
* Phosphorylation
## Footnote
These modifications are important for protein functionality.
136
What are the **cis and trans faces** of the Golgi?
* Cis = receiving side (near ER)
* Trans = shipping side (near plasma membrane)
## Footnote
This organization is essential for the Golgi's function in processing and shipping proteins.
137
What is the **trans-Golgi network (TGN)**?
A sorting hub that packages cargo into clathrin-coated vesicles
## Footnote
The TGN is critical for directing proteins to their final destinations.
138
What is **exocytosis**?
Fusion of secretory vesicles with the plasma membrane to release contents
## Footnote
Exocytosis is essential for secretion and membrane recycling.
139
What is **constitutive exocytosis**?
Continuous, unregulated secretion in all cells
## Footnote
This process is vital for maintaining cell homeostasis.
140
What is **regulated exocytosis**?
Ca²⁺-triggered secretion in response to a signal
## Footnote
Regulated exocytosis is important for processes like neurotransmitter release.
141
What is **endocytosis**?
Uptake of extracellular material via vesicles formed from the plasma membrane
## Footnote
Endocytosis is crucial for nutrient uptake and cell signaling.
142
What is **receptor-mediated (clathrin-dependent) endocytosis**?
Uptake of specific ligands bound to receptors using clathrin-coated vesicles
## Footnote
This mechanism allows for selective uptake of molecules.
143
What is **clathrin**?
A triskelion-shaped protein that forms a vesicle coat
## Footnote
Clathrin is essential for the formation of vesicles during endocytosis.
144
What role does **dynamin** play in endocytosis?
Uses GTP to pinch off vesicles from the membrane
## Footnote
Dynamin is crucial for the final steps of vesicle formation.
145
What is an **early endosome**?
Sorting center that determines cargo fate
## Footnote
Early endosomes play a key role in the processing of internalized materials.
146
What is a **lysosome**?
An acidic organelle containing digestive enzymes (acid hydrolases)
## Footnote
Lysosomes are essential for breaking down waste materials and cellular debris.
147
What activates **lysosomal enzymes**?
Low pH (<5) generated by V-ATPase proton pumps
## Footnote
The acidic environment is necessary for optimal enzyme activity.
148
What is the main function of the **nucleus**?
Storage and regulation of genetic information
## Footnote
The nucleus is the control center of the cell.
149
What is **chromatin**?
DNA complexed with histone proteins
## Footnote
Chromatin structure is crucial for gene regulation and DNA packaging.
150
What is **euchromatin**?
Lightly packed, transcriptionally active chromatin
## Footnote
Euchromatin is associated with active gene expression.
151
What is **heterochromatin**?
Densely packed, transcriptionally inactive chromatin
## Footnote
Heterochromatin is typically found in regions of the genome that are not actively expressed.
152
What is the difference between **constitutive and facultative heterochromatin**?
* Constitutive: always inactive
* Facultative: can switch to active euchromatin
## Footnote
This distinction is important for understanding gene regulation.
153
What are **chromosome territories**?
Discrete regions occupied by individual chromosomes in the nucleus
## Footnote
This organization helps regulate gene expression and DNA replication.
154
What is the **nuclear envelope**?
A double membrane surrounding the nucleus
## Footnote
The nuclear envelope separates the contents of the nucleus from the cytoplasm.
155
How is the **outer nuclear membrane** related to the ER?
It is continuous with the rough ER
## Footnote
This continuity facilitates the transport of proteins between the nucleus and the ER.
156
What are **nuclear pore complexes (NPCs)**?
Large protein structures that regulate transport between nucleus and cytoplasm
## Footnote
NPCs are essential for the exchange of materials between the nucleus and the cytoplasm.
157
What can freely diffuse through **NPCs**?
Small molecules and proteins ≤40 kDa
## Footnote
This size limitation is important for regulating nuclear transport.
158
How are large proteins transported into the nucleus?
Via nuclear localization signals and importins using GTP
## Footnote
This mechanism ensures that proteins are correctly targeted to the nucleus.
159
What are **exportins**?
Proteins that transport cargo out of the nucleus
## Footnote
Exportins are crucial for the regulation of nuclear-cytoplasmic transport.
160
What is the **nuclear lamina**?
A protein meshwork lining the inner nuclear membrane
## Footnote
The nuclear lamina provides structural support to the nucleus.
161
What proteins make up the **nuclear lamina**?
* Lamins A
* Lamins B
* Lamins C
* Lamin-associated proteins
## Footnote
These proteins are essential for maintaining nuclear structure and organization.
162
What is the function of the **nucleolus**?
rRNA transcription and ribosome subunit assembly
## Footnote
The nucleolus is crucial for ribosome production.
163
What are **speckles**?
Storage sites for RNA-processing components
## Footnote
Speckles play a role in the regulation of gene expression.
164
What are **Cajal bodies**?
Sites of RNA and histone mRNA processing
## Footnote
Cajal bodies are involved in the assembly of ribonucleoprotein complexes.
165
What are the key characteristics of **eukaryotes**?
* Compartmentalization
* Regulated trafficking
* Complex signaling
* Nuclear control
## Footnote
These characteristics distinguish eukaryotic cells from prokaryotic cells.
BioChem
flashcards
Decks in class (28)
# Cards
-
in class day 113
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ch117
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ch1 solutions49
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ch1 solutionsd148
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c h1 solutionsd from him48
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ch 1 test bank0
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yaya30
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ch 2chatgpt60
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quiz 2 book98
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ch2 study guide for quiz chat bru67
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questionsfrombookch2butcxhatcondenseddownfromstudygudise74
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chapter 1 me147
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;ec 32
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chapter 2 me165
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chapter 1 activity 140
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chapter 1 activity 255
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chapter 2 lecture 1 activity41
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chapter 2 lectuer part 2 activity63
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chapter 2 lecture 2 actviity 345
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quiz 3 study guide ]92
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condensed questions268
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quizzes20
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quizzes chat other56
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quizzes COPY20
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archea otter chat82
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chapter 2 lecture 1 activity COPY41
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chapter 3 l3ctuure 2 actibvity 244
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chapter 5 overview11
