Chapter 4.6: The Cytoskeleton Flashcards
What are the 3 fibers that compose the cytoskeleton?
- Actin Filaments (Microfilaments)
- Microtubules
- Intermediate Filaments
Define actin
Actin- one of the two major proteins that make up vertebrate muscle
What is the size of actin filaments?
7 nm in diameter
Which cytoskelelatal element is 7 nm in diameter?
actin filament
What are actin filaments composed of?
Composed of two protein chains loosely twined together
What are actin filaments responsible for?
Responsible for cellular movements such as contraction, crawling, “pinching” during division, and formation of cellular extensions
What is the size of microtubule?
25 nm in diameter
What are microtubules composed of?
Composed of a ring of 13 protein protofilaments
What are microtubule responsible for?
Facilitate cellular movement, organize the cytoplasm, and are responsible for moving materials within the cell itself
What are intermediate filaments composed of?
Composed of a system of tough, fibrous protein molecules twined together in an overlapping arrangement
What is the size of intermediate filament?
8 to 10 nm in diameter
Which cytoskeletal element is
actin filaments
Which cytoskeletal element is Composed of two protein chains loosely twined together?
actin filaments
Which cytoskeletal element Exhibit polarity?
actin filaments
Which cytoskeletal element Spontaneously form?
actin filaments
Which cytoskeletal element Responsible for cellular movements such as contraction, crawling, “pinching” during division?
actin filaments
Which cytoskeletal element formation of cellular extensions?
actin filaments
Which cytoskeletal element is largest of the cytoskeletal elements ?
microtubules
Which cytoskeletal element is 25 nm in diameter?
microtubules
Which cytoskeletal element is Composed of a ring of 13 protein protofilaments?
microtubules
Which cytoskeletal element Tube-shaped?
microtubules
Which cytoskeletal element Facilitate cellular movement?
microtubules
Which cytoskeletal element organize the cytoplasm?
microtubules
Which cytoskeletal element is the responsible for moving materials within the cell itself?
microtubules
Which cytoskeletal element is Most durable of the cytoskeletal elements?
intermediate filaments
Which cytoskeletal element is Composed of a system of tough, fibrous protein molecules twined together in an overlapping arrangement?
intermediate filaments
Which cytoskeletal element is 8 to 10 nm in diameter?
intermediate filaments
Define centrioles
a cytoplasmic organelle located outside the nuclear membrane, identical in structure to a basal body; found in animal cells and in the flagellated cells of other groups; divides and organizes spindle fibers during mitosis and meiosis
What is a cytoplasmic organelle located outside the nuclear membrane, identical in structure to a basal body; found in animal cells and in the flagellated cells of other groups; divides and organizes spindle fibers during mitosis and meiosis?
centrioles
Define centrosome
o Centrosome- the region surrounding the pair of centrioles in almost all animal cells
Define pericentriolar material
o Pericentriolar Material- surrounds the centrioles in the centrosome; contains ring-shaped structures composed of tubulin; can nucleate the assembly of microtubules in animal cells
Define microtubule-organizing centers
structures that can nucleate the assembly of microtubules
What are the 4 components required to move material along microtubes?
- • A vesicle or organelle that is to be transported
- • A motor protein that provides the energy-driven motion
- • A connector molecule that connects the vesicle to the motor molecule
- • Microtubules on which the vesicles will ride
Define kinesis
Kinesin- a motor protein that uses ATP to power its movement toward the cell periphery, dragging the vesicle with it as it travels along the microtubule toward the plus end
Define dynein
Dynein- a motor protein which directs movement in the opposite direction along microtubules toward the minus end, inward toward the cell’s center
Describe the plasma membrane
Phospholipid bilayer with embedded proteins
Describe the nucleus
Structure (usually spherical) that contains chromosomes and is surrounded by double membrane
Describe the chromosomes
Long threads of DNA that form a complex with protein
Describe the nucleolus
Site of genes for rRNA synthesis
Describe the ribosomes
Small, complex assemblies of protein and RNA, often bound to ER
Describe the endoplasmic reticulum (ER)
network of internal membranes
Describe the golgi apparatus
Stacks of flattened vesicles
Describe the lysosomes
Vesicles derived from Golgi apparatus that contain hydrolytic digestive enzymes
Describe the microbodies
Vesicles that are formed from incorporation of lipids and proteins and that contain oxidative and other enzymes
Describe the mitochondria
Bacteria-like elements with double membrane
Describe the chloroplasts
Bacteria-like elements with double membrane surrounding a third, thylakoid membrane containing chlorophyll, a photosynthetic pigment
Describe the cytoskeleton
Network of protein filaments
Describe the flagella (cilia)
Cellular extensions with 9 + 2 arrangement of pairs of microtubules
Describe the cell wall
Outer layer of cellulose or chitin; or absent
Which eukaryotic cell structure is being described? Phospholipid bilayer with embedded proteins
plasma membrane
Which eukaryotic cell structure is being described? Structure (usually spherical) that contains chromosomes and is surrounded by double membrane
nucleus
Which eukaryotic cell structure is being described? Long threads of DNA that form a complex with protein
chromosomes
Which eukaryotic cell structure is being described? Site of genes for rRNA synthesis
nucleolus
Which eukaryotic cell structure is being described? Small, complex assemblies of protein and RNA, often bound to ER
ribosomes
Which eukaryotic cell structure is being described? Network of internal membranes
endoplasmic reticulum (ER)
Which eukaryotic cell structure is being described? Stacks of flattened vesicles
golgi apparatus
Which eukaryotic cell structure is being described? Vesicles derived from Golgi apparatus that contain hydrolytic digestive enzymes
lysosomes
Which eukaryotic cell structure is being described? Vesicles that are formed from incorporation of lipids and proteins and that contain oxidative and other enzymes
microbodies
Which eukaryotic cell structure is being described? Bacteria-like elements with double membrane
mitochondria
Which eukaryotic cell structure is being described? Bacteria-like elements with double membrane surrounding a third, thylakoid membrane containing chlorophyll, a photosynthetic pigment
chloroplasts
Which eukaryotic cell structure is being described? Network of protein filaments
cytoskeleton
Which eukaryotic cell structure is being described? Cellular extensions with 9 + 2 arrangement of pairs of microtubules
flagella (cilia)
Which eukaryotic cell structure is being described?
Outer layer of cellulose or chitin; or absent
What is the function of the plasma membrane?
Regulates what passes into and out of cell; cell-to-cell recognition; connection and adhesion; cell communication
Which eukaryotic cell structure has the following function? Regulates what passes into and out of cell
plasma membrane
Which eukaryotic cell structure has the following function? cell-to-cell recognition
plasma membrane
Which eukaryotic cell structure has the following function? connection and adhesion
plasma membrane
Which eukaryotic cell structure has the following function? cell communication
plasma membrane
What is the function of the nucleus?
Instructions for protein synthesis and cell reproduction; contains genetic information
Which eukaryotic cell structure has the following function? Instructions for protein synthesis and cell reproduction
nucleus
Which eukaryotic cell structure has the following function? contains genetic information
nucleus
What is the function of the chromosomes?
Contain hereditary information used to direct synthesis of proteins
Which eukaryotic cell structure has the following function? Contain hereditary information used to direct synthesis of proteins
chromosomes
What is the function of the nucleolus?
Synthesis of rRNA and ribososme assembly
Which eukaryotic cell structure has the following function? Synthesis of rRNA and ribososme assembly
nucleolus
What is the function of the ribosomes?
Site of protein synthesis
Which eukaryotic cell structure has the following function? Site of protein synthesis
ribosomes
What is the function of the endoplasmic reticulum (ER)?
Intracellular compartment forms transport vesicles; participates in lipid synthesis and synthesis of membrane or secreted proteins
Which eukaryotic cell structure has the following function? Intracellular compartment forms transport vesicles
endoplasmic reticulum (ER)
Which eukaryotic cell structure has the following function? participates in lipid synthesis and synthesis of membrane or secreted proteins
endoplasmic reticulum (ER)
What is the function of the golgi apparatus?
Packages proteins for export from cell; forms secretory vesicles
Which eukaryotic cell structure has the following function? Packages proteins for export from cell
golgi apparatus
Which eukaryotic cell structure has the following function? forms secretory vesicles
golgi apparatus
What is the function of the lysosomes?
Digest worn-out organelles and cell debris; digest material taken up by endocytosis
Which eukaryotic cell structure has the following function? Digest worn-out organelles and cell debris
lysosomes
Which eukaryotic cell structure has the following function? digest material taken up by endocytosis
lysosomes
What is the function of the microbodies?
Isolate particular chemical activities from rest of cell
Which eukaryotic cell structure has the following function? Isolate particular chemical activities from rest of cell
microbodies
What is the function of the mitochondria?
“Power plants” of the cell; sites of oxidative metabolism
Which eukaryotic cell structure has the following function? “Power plants” of the cell;
mitochondria
Which eukaryotic cell structure has the following function? sites of oxidative metabolism
mitochondria
What is the function of the chloroplasts?
Sites of photosynthesis
Which eukaryotic cell structure has the following function? Sites of photosynthesis
chloroplasts
What is the function of the cytoskeleton?
Structural support; cell movement; movement of vesicles within cells
Which eukaryotic cell structure has the following function? Structural support
cytoskeleton
Which eukaryotic cell structure has the following function? cell movement
cytoskeleton
What is the function of the flagella?
Motility or moving fluids over surfaces
Which eukaryotic cell structure has the following function? Motility or moving fluids over surfaces
flagella
What is the function of the cell wall?
protection and support
Which eukaryotic cell structure has the following function? protection
cell wall
Which eukaryotic cell structure has the following function? support
cell wall
Which eukaryotic cell structure has the following function? movement of vesicles within cells
cytoskeleton