Term
| What is a channel and how does it open and close? |
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Definition
◦ Forms a corridor through the membrane
◦ Can be opened or closed in response to cell signals
ex)Aquaporin, Calcium channels |
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Term
| What are carrier proteins? give an example |
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Definition
Forms different configurations that alternatively expose interior binding sites to opposite sides of membrane
ex) Glucose transporter |
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Term
| Describe Active Transport and an example |
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Definition
◦ Sodium-potassium pump (an example of an ‘antiporter’)
Used to establish electrical gradients that
represent potential energy
◦ Membrane potential (voltage)
◦ Examples:
Proton pump
Sodium-Potassium pump
This potential energy then can drive active
transport of other molecules
◦ Example:
Sucrose-H+ cotransporter |
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Term
| What are the two types of motility? |
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Definition
Flagella
Motor turns hook and filament |
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Term
| Describe Flagella movement |
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Definition
Allow cells to ‘swim’
Can ‘push’ or ‘pull’ |
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Term
| Describe Motor turns hook and filament |
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Definition
Corkscrew action
Powered by proton
motive force
-Compare ATP synthase |
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Term
| What are Flagella and Cilia? describe the structure |
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Definition
Filamentous extensions from
cell body
Cylinders of 9 microtubule
doublets with two in center
Extend from basal body, which
has 9 triplets |
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Term
| What do Flagella and Cilia do? |
|
Definition
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Term
| How do flagella and cilia drive motility? |
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Definition
Flagella – long, singular (or few),
undulating
Cilia – short, many, power strokes |
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Term
| Describe the Cytoskeleton? |
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Definition
◦Maintains cell shape
◦ Supports organelles
◦ Facilitates motility
◦ Facilitates vesicle transport
◦ Fibers of three types |
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Term
| What are the three types of fibers in the cytoskeleton? |
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Definition
-Microtubules
-Microfilaments
-Intermediate filaments |
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Term
| Describe the subunit, structure, diameter, protein subunits, and main functions of microtubules |
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Definition
Subunit: Tubulin
Structure: Hollow tubes; wall consists of 13 columns of tubulin molecules
Diameter: 25 nm with 15 nm lumen
Protein subunits: Tubulin, a dimer consisting of a-tubulin and B-tubulin
Main functions: Maintenance of cell shape (compression-resisting "girders"), Cell motility (cilia or flagella), Chromosome movements in cell division, Organelle movements |
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Term
| Describe the subunit, structure, diameter, protein subunits, and main functions of Microfilaments |
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Definition
Subunit:
Structure: Two intertwined strands of actin, each a polymer of actin subunits
Diameter: 7 nm
Protein subunits: Actin
Main functions: maintenance of cell shape (tension-bearing elements), changes in cell shape, muscle contraction, cytoplasmic streaming, cell motility (as in pseudopodia), Cell division (cleavage furrow formation) |
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Term
| Describe the subunit, structure, diameter, protein subunits, and main functions of |
|
Definition
Subunit: various
Structure: Fibrous proteins supercoiled into thicker cables
Diameter: 8-12 nm
Protein subunits: one of several different proteins (such as keratins), depending on cell type
Main functions: maintenance of cell shape ( tension-bearing elements), anchorage of nucleus and certain other organelles, formation of nuclear lamina |
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Term
| What is used for vesicular transport? |
|
Definition
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Term
| What is frequently involved in contraction and movement? |
|
Definition
|
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Term
| How are microfilaments involved in contraction and movement? |
|
Definition
Muscle contraction
Amoeba
pseudopodia
Cytoplasmic
streaming |
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Term
| What are some types of intercellular junctions? |
|
Definition
| Tight junctions, desmosomes, gap junction, Plasmodesmata |
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Term
| What is a tight junction? |
|
Definition
| Link cells with fluid tight barrier |
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Term
|
Definition
| Structural attachment between cells – link intercellular matrix |
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Term
|
Definition
| Allow flow between cells in animals |
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Term
|
Definition
| Allow flow between cells in plants |
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Term
| Describe the bacterial cell wall with gram staining |
|
Definition
Gram staining distinguishes bacteria based on
thickness of peptidoglycan layer
positive-traps crystal violet
negative-crystal violet is easily rinsed away, revealing red dye |
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Term
| What are some bacterial extracellular components? |
|
Definition
◦ Capsules, Fimbriae
Adherence, protection, communication |
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Term
| Describe the cell wall in eukaryotes |
|
Definition
Extracellular structure seen in plants, some fungi,
and protists (e.g. diatoms)
Outside of plasma membrane
◦ Protect cells
◦ Maintain cell shape |
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Term
| Describe the plant cell wall |
|
Definition
◦ Primary Cell Wall
◦ Secondary Cell Wall
◦ Middle Lamella = contains pectins – sticky polysaccharides that serve as glue to hold adjacent cells together |
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Term
| What is the extracellular matrix and what is its importance? |
|
Definition
Extracellular structure found in animals
◦ Support
◦ Adhesion
◦ Movement
◦ Regulation |
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Term
| What is the extracellular matrix made of? |
|
Definition
Composed primarily of glycoproteins
Collagen
Proteoglycans |
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