Rider Biology 1.10–1.11 — Cytoskeleton, Cell Adhesion & ECM
Call Kai
Learn
Practice Test
Spaced Repetition
Match
Flashcards
Knowt Play1/149
There's no tags or description
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced | Call with Kai | Chat |
|---|
No analytics yet
Send a link to your students to track their progress
150 Terms
What is the cytoskeleton?
An internal spiderweb-like network of protein filaments inside the cell.
What are the three main cytoskeletal filament types?
Microtubules, intermediate filaments, and actin microfilaments.
Which cytoskeletal component is the widest?
Microtubules.
What is the approximate diameter of a microtubule?
About 25 nm.
Are microtubules hollow or solid?
Hollow.
What proteins make up microtubules?
α-tubulin and β-tubulin.
What structural job do microtubules perform?
They help support the cell and resist compressive forces.
What building analogy does Rider use for microtubules?
Structural columns.
Where do microtubules often begin?
At the centrosome near the nucleus.
Where do microtubules generally extend?
From the centrosome toward the edges of the cell.
What is the centrosome?
A central location near the nucleus from which many microtubules extend.
Which cytoskeletal component is medium-sized?
Intermediate filaments.
What is the approximate diameter of intermediate filaments?
About 10 nm.
Are intermediate filaments hollow or solid?
Solid fibers.
What proteins can make up intermediate filaments?
Keratins or other fibrous proteins.
What is a major role of intermediate filaments?
Provide mechanical support and connect anchoring points across the cell.
Which cytoskeletal component is the thinnest?
Actin microfilaments.
What is the approximate diameter of actin microfilaments?
About 7 nm.
What protein makes actin microfilaments?
Actin.
How are actin microfilaments arranged?
As two intertwined strands.
Where are actin microfilaments especially abundant?
Just inside the plasma membrane.
What do actin microfilaments do near the plasma membrane?
Form a dense supporting web beneath it.
What is the size order of the three cytoskeletal components from widest to thinnest?
Microtubules → intermediate filaments → microfilaments.
What are the approximate diameters in order?
25 nm → 10 nm → 7 nm.
What is another important job of the cytoskeleton besides structural support?
It acts as tracks for moving molecules, vesicles, and organelles.
What cytoskeletal structure acts like train tracks for cargo transport?
Microtubules.
What moves cargo along microtubules?
Motor proteins.
What kinds of cargo can motor proteins move?
Molecules, vesicles, and organelles.
How do motor proteins attach to cargo?
They grab receptors on the cargo.
What energy source powers motor proteins?
ATP.
What does kinesin generally do?
Moves cargo outward toward the + end of a microtubule.
What does dynein generally do?
Moves cargo inward toward the − end of a microtubule.
Which direction does kinesin usually move?
Outbound or + direction.
Which direction does dynein usually move?
Inbound or − direction.
Where is the microtubule − end generally located in Rider's figure?
Toward the center of the cell.
Where is the microtubule + end generally located?
Toward the edge of the cell.
What is the simplest analogy for microtubule cargo transport?
Microtubule = track, motor protein = engine, cargo = freight, ATP = fuel.
A vesicle needs to move toward the cell edge. Which motor protein generally helps?
Kinesin.
An organelle needs to move toward the center of the cell. Which motor protein generally helps?
Dynein.
Do motor proteins use ATP with each step?
Yes.
What is a flagellum?
A long cell-surface appendage used for movement.
What is the plural of flagellum?
Flagella.
What is a mammalian example of a cell with a flagellum?
A sperm cell.
What are cilia?
Short, numerous finger-like appendages on the cell surface.
Are cilia generally longer or shorter than flagella?
Shorter.
Are cilia generally more or less numerous than flagella?
More numerous.
What is one major job of cilia in the respiratory tract?
Sweep substances along the cell surface.
What is another role of some cilia?
Sense fluid motion around the cell.
How do eukaryotic cilia and flagella work internally?
They use microtubules, dynein motors, crosslinking proteins, and ATP.
What motor protein helps generate movement in cilia and flagella?
Dynein.
What does dynein try to do inside a cilium or flagellum?
Slide one microtubule pair relative to another.
What prevents microtubule pairs from freely sliding apart?
Crosslinking proteins.
What happens because the microtubules cannot slide very far?
They bend.
What produces the waving motion of cilia and flagella?
Repeated bending of the microtubule structure.
What powers dynein in cilia and flagella?
ATP.
What is the 9+2 arrangement?
Nine outer microtubule pairs plus two central individual microtubules.
Where are the nine pairs located?
Around the outside of the cilium or flagellum.
Where are the two single microtubules located?
In the center.
What surrounds eukaryotic cilia and flagella?
A protrusion of the plasma membrane.
How wide are eukaryotic cilia and flagella according to Rider?
About 0.25 µm wide.
How long are flagella according to Rider?
About 100–200 µm.
How long are cilia according to Rider?
About 2–20 µm.
Do eukaryotic cilia and flagella use the same basic internal mechanism?
Yes.
Do prokaryotic flagella work the same way as eukaryotic flagella?
No.
What should you identify in Figure 23(a)?
Microtubules, intermediate filaments, microfilaments, centrosome, nucleus, and plasma membrane.
What is the main idea of Figure 23(b)?
Motor proteins use ATP to carry cargo along microtubules.
What is the main idea of Figure 24?
Microtubules and dynein create the bending motion of eukaryotic cilia and flagella.
What is a cell adhesion molecule?
A sticky surface molecule that helps a cell attach to other cells or to the extracellular matrix.
How does Rider describe cell adhesion molecules?
As Velcro-like sticky molecules.
What does ECM stand for?
Extracellular matrix.
What is the extracellular matrix?
A spiderweb-like network of molecules between and around cells.
Where is the cytoskeleton located?
Inside the cell.
Where is the extracellular matrix located?
Outside cells, especially between them.
What is the main difference between cytoskeleton and ECM?
Cytoskeleton supports the inside of the cell; ECM forms a support network outside the cell.
What are the four major cell adhesion molecule types Rider lists?
Cadherins, immunoglobulin-superfamily cell adhesion molecules, selectins, and integrins.
What do cadherins bind to?
Cadherins on neighboring cells.
What shape does Rider describe cadherins as having?
Hook-shaped.
What ion do cadherins require to work properly?
Calcium ions.
What happens to cadherins if calcium is removed?
They lose their rigid hook shape.
What do immunoglobulin-superfamily cell adhesion molecules bind to?
Members of the same immunoglobulin-superfamily on neighboring cells.
What are immunoglobulin-superfamily adhesion molecules related to?
Immunoglobulins or antibodies.
What do selectins bind to?
Glycans, or sugars, on neighboring cell surfaces.
What are glycans?
Sugars.
What do integrins bind to?
Extracellular matrix glycoproteins.
Which adhesion molecule is especially important for cell-to-ECM attachment?
Integrin.
Which adhesion molecule binds matching molecules on neighboring cells and requires calcium?
Cadherin.
Which adhesion molecule binds sugars on a neighboring cell?
Selectin.
What are major components of the extracellular matrix?
Glycoproteins, fibrous proteins, and proteoglycans.
What are examples of ECM glycoproteins?
Fibronectin and laminin.
What are examples of fibrous ECM proteins?
Collagen and elastin.
What is an example of an ECM crosslinking glycoprotein?
Nidogen.
What is an example of an ECM proteoglycan?
Perlecan.
What is a glycoprotein?
A molecule made of protein and sugar in which protein is the more dominant component.
What is a proteoglycan?
A molecule made of protein and sugar in which sugar is the more dominant component.
Which has more protein than sugar: glycoprotein or proteoglycan?
Glycoprotein.
Which has more sugar than protein: glycoprotein or proteoglycan?
Proteoglycan.
Why are sugar branches useful in the ECM?
They form sticky branching structures that help with adhesion.
What is collagen's general role in the ECM?
A strong fibrous structural protein.
What is elastin's general role in the ECM?
A fibrous protein that contributes to elastic properties.
What is an anchoring junction?
A strong cell-to-cell junction that mechanically connects neighboring cells.