Term
| What cell component controls cell structure and movement? |
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Definition
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Term
| What two main components make up the cytoskeleton? |
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Definition
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Term
Three main types of cytoskeleton
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Definition
| Microfilament, Intermediate Filaments, Microtubules |
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Term
Characteristics of Intermediate Filaments
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Definition
1. Mainly for structure support
2. Toughest and most durable
3. Span the cytosol
4. Link cells at cell junctions
5. Strengthen cell junctions |
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Term
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Definition
Junctions made between cells
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Term
Eight tetramers of intermediate polypeptides makes
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Definition
One rope of intermediate filament
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Term
Characteristics of intermediate filament proteins
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Definition
1. Middle has the chemical capacity to make more of itself
2. The end globular proteins anchor to one another
3. Work as cell's rebar |
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Term
Intermediate Filament Chart
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Definition
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Term
Intermediate filaments associate with
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Definition
Microtubules and Plectin (links IF to other proteins)
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Term
How are IF 'unraveled' in the nuclear lamina?
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Definition
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Term
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Definition
Movement and organization center (centrosomes)
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Term
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Definition
Long strand of tubulin heterodimer.
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Term
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Definition
Abundant protein found in cells
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Term
Gammatubulin grows out of
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Definition
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Term
Which ends grow away from gammatubulin?
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Definition
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Term
Why do cells need gammatubulin?
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Definition
| Allows organization of microtubules at right time/place. |
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Term
| GTP binds to tubulin _______ the end of the microtubule |
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Definition
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Term
| GDP binds to tubulin _______ the end of the microtubule |
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Definition
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Term
Capping microtubule proteins does two things..
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Definition
1. Create polarity of the cell
2. Stimulates growth in a direction |
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Term
| By having invaginated membrane____________ can get into the cell. |
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Definition
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Term
| How do we get calcium stores to open? |
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Definition
- Utilize neuromuscular junction (electrical signals converted to chemical signal)
- Neurotransmitter binds to receptor, releases Ca
- Ligate gated ion channels |
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Term
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Definition
| Keeps actin away from myosin until calcium disrupts it so it can bind |
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Term
Two outcomes of creating polarity in the cell
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Definition
1. Microtubules help create axons
2. Direct movement and transport |
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Term
| Two types of motor proteins used for movement in microtubules |
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Definition
1. Dynein- toward minus end
2. Kinesin- toward plus end |
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Term
How could a microtubule allow flagella movement?
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Definition
Motors to help crosslink other microtubules
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Term
How can microtubules bend?
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Definition
Fixed link proteins allow microtubules to bend
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Term
What kind of filament is actin?
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Definition
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Term
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Definition
Maintain shape and contraction
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Term
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Definition
Single polypeptide of actin
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Term
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Definition
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Term
Dynamic instability of F-actin is...
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Definition
- It can add or subtract from either end with ATP
- Hydrolization favors subtraction |
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Term
Actin must ______ to function
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Definition
| Interact and couple with other proteins |
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Term
_____ and ______ bind together to form cell cortex
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Definition
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Term
Actin's role in cell mobility
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Definition
1. Rearrange cell so it can walk along the matrix
2. Repolymerizes filaments to favor movement |
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Term
Filopodium –
Lamellipodium –
Contractile Bundle – |
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Definition
Filopodium – long feeler of actin
Lamellipodium – fills in space between filopodium
Contractile Bundle – linked the filopodium and Lamellipodium to the rest of the cell |
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Term
Describe the relationship between actin and myosin
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Definition
| Myosin helps move the filaments of actin through contraction |
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Term
Main motor component of muscle contractions
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Definition
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Term
What area of myosin associates with actin?
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Definition
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Term
Muscle cells have multiple ____
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Definition
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Term
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Definition
Composed of myosin II and actin bundled together = (sarcomere)
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Term
Order from sarcomere to muscle
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Definition
| Actin & Myosin II --> Sarcomere --> Myofibril --> Muscle Cell --> Muscle |
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Term
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Definition
Contractile unit of myosin II and actin that makes up myofibril
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Term
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Definition
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Term
What happens to the sarcomeres during contraction?
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Definition
The myosin/actin interaction pulls heads inward and ATP hydrolysis drives contraction.
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Term
Examples for:
Microfilaments
Intermediate Filaments
Microtubules |
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Definition
Microfilaments - actin
Intermediate filaments - various
Microtubules - alpha and beta tubulin
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Term
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Definition
Long strand of tubulin heterodimers
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Term
| Microtubules have polarity - which ends point away from gammatubulin? |
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Definition
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Term
What in your body is not made up (entirely) of cells?
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Definition
| Extracellular Matrix (ECM) - makes up structural elements of the body |
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Term
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Definition
- Ca moves out of the way and allows, actin and myosin to bind
- Control of Ca decided whether or not binding will happen
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Term
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Definition
1. Tensile strength – support tissues and organs
2. Structural support – support tissues and organs
3. Flexibility – strength and movement
4. Shock absorption
5. Cue for cell growth/development (“home”) – cells know what they are and what they need to become
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Term
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Definition
| Diverse array of proteins and it self assembles |
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Term
Why does collagen only assemble outside of cells?
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Definition
| Cell can’t accommodate the collagen inside |
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Term
How do we assemble proteins inside cell?
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Definition
ER, cytosol, chaperone proteins
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Term
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Definition
Cells that exist in tissue and they create ECM and structure
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Term
| Fibronectin's purpose in cells |
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Definition
Links collagen to cells because it has collagen binding site and cell attachment site
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Term
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Definition
| Proteins that help cells bind to matrix |
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Term
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Definition
- Made up of two kind of proteins
-(HOLDING ORDER) Integrin -> fibronectin -> collagen
- Linked to microfilaments
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Term
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Definition
Integrins link cells to the ECM and also connect to the actin cytoskeleton
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Term
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Definition
| Provides protection against compression, shock absorption, lubrication, and space filling |
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Term
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Definition
| Seals neighboring cells with epithelial sheet to prevent leakage between cells |
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Term
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Definition
Joins an actin bundles between cells
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Term
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Definition
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Term
|
Definition
| Forms channels that allow water soluble molecules, ions to pass from cell to cell |
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Term
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Definition
Anchors IF in a cell to the basal lamina
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Term
Five Types of Epithelial Cell Junctions
(TADGH) |
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Definition
| Tight, Adherins, Desmosomes, Gap, Hemidesmosome |
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Term
Cadherins -
Homotypic protein - |
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Definition
Cadherins -surface cell proteins
Homotypic protein - binds to other cells |
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Term
| Caherins link what kind of junctions? |
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Definition
| Desmosomes and adheren; allow flow of molecules |
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Term
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Definition
| Integral linking proteins that seal |
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Term
| Desmosomes link _______ and ________ |
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Definition
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Term
|
Definition
– Cell adherence to extracellular matrix
- No cadherin, but integrins and linkage to intermediate filaments
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Term
| Gap Junctions allow ______ through cells |
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Definition
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Term
|
Definition
| Protein connections found in gap junctions |
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Term
Reasons cells need to sense and respond to their environment
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Definition
- Relay a message
- Survival
- Tracking down nutrients
- Division
- Cell Death
- Immune System cells
- Reproduction
- Response to Light/Dark, Hot/Cold = Environment
- Change Shape |
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Term
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Definition
Converting one type of signal to another
Example: extracellular signal -> intracellular signal
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Term
| Steps of signal Transduction (6 Steps) |
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Definition
1. Arrival of signal in a cell
2. Perception of the signal
3. Transmission of signal into the cell
4. Passing of the signal
5. Arrival of the signal at destination
6. Turn off the signal |
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Term
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Definition
| The extracellular substance that initiates intracellular signaling |
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Term
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Definition
Binds to the first messenger
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Term
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Definition
| Molecule that binds to a receptor |
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Term
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Definition
| Events that happen in a specific order after the transfer of original signal |
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Term
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Definition
Intermediate molecule that is part of the cascade that relays signal from receptor to target molecule
Example: Calcium |
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Term
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Definition
What happens to the cell
Ex. Change in gene expression |
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Term
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Definition
| Final protein target that determines the behavior of the cell |
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Term
| Four Common Themes in Cell Signaling |
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Definition
1. Specificity (Structure and Function)
2. Amplification
3. Cross-Talk
4. Concentration |
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Term
| Types of Signaling Molecules |
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Definition
1. Hormones
2. Local Mediators
3. Neurotransmitters
4. Contact Dependant Signaling Molecules
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Term
|
Definition
1. Cell makes hormones
2. Hormone travels through bloodstream
3. Recognized by target cell
4. Triggers cascade of events |
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Term
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Definition
1. Signal made in one cell
2. Diffuses through extracellular fluid to target
3. Bind to receptor on target cell |
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Term
|
Definition
1. Signal is made and recognized all by the same cell
2. Local mediators
Why would it do this?
Amplify signal |
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Term
|
Definition
1. Signal molecule binds to receptor on target cell
2. Causes cascade
3. Flow of neurotransmitters into target cell
4. Membrane voltage changes |
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Term
| Contact-dependent signaling |
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Definition
1. Direct contact between two cells
2. Signal molecule embedded in membrane
3. One of the cells become specialized. Cause other cells to not differentiate. – other cells are notch cells (receptors)
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Term
| Effects of signaling molecules |
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Definition
1. Contraction rate
2. Secretion
3. Apoptosis |
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Term
| Problem: if a cell is bombarded with different signals, how does it “know” which one to respond to and which ones to disregard? |
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Definition
The strength of the signal, gradient, protein receptors (cell surface, intracellular)
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Term
| Two Types of Cell Receptors |
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Definition
1. Intracellular
2. Cell Surface |
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Term
| Intracellular Receptors and Response Elements of Cortisol into the cell |
|
Definition
1. Change of conformation allows cortisol to get into the nucleus.
2. Binds to a response element – DNA sequence (enhancers) = increases transcription of a target gene
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Term
|
Definition
A 2nd messenger that is made from a molecule of GTP
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Term
| Steps in Intracellular signaling molecules (CASCADE) |
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Definition
1. Relay and spread signal through the cell
2. Amplify the signal
3. Integrate several signals
4. Distribute signal to more than one pathway
5. Scaffold |
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Term
|
Definition
| Way to bring cells together |
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Term
|
Definition
MAP kinase cascade uses scaffolding to get all kinases together
ex. MAPKKK
MAPKK
MAPK
TXN factor
Phosphorylating down the line |
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Term
|
Definition
1. Cytoplasmic hotspots – signals concentrated
2. Lipid Rafts – area of thick membrane – concentrates signal
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Term
| Signaling molecules can act as _________ ________ |
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Definition
| molecular switches (on OR off) |
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Term
| Three Types of Cell Surface Receptors |
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Definition
1. Ion-channel coupled receptors
2. G-protein-coupled receptors
3. Enzyme-coupled receptors
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Term
Ion-channel coupled receptors example with Acetylylcoline
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Definition
When signaling acetylylcoline molecule binds, it opens calcium ion channel receptor
LETS IONS IN |
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Term
| G-protein coupled receptors (GPCRs) |
|
Definition
1. Ligand binds, changes conformation of GCPR.
2. Allows for interaction with G-protein.
3. It’s achored in the membrane – associates with GPCR
N-terminis in extracellular space; C-terminis inside
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Term
|
Definition
| Sense molecules outside the cell and activate signal transduction inside the cell |
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Term
|
Definition
| Works as molecular switch, regulate ion channels, and activate enzymes |
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Term
| Adenylyl cyclase turns into ________ during enzyme activation |
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Definition
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Term
| What theme happens when enzymes are activated? |
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Definition
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Term
|
Definition
cAMP is good because water soluble, high aTP, easily diffuses
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Term
| cAMP is a __________ because it is ___________ |
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Definition
| Second messenger; readily available |
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Term
|
Definition
| It phosphorylates a protein using ATP. |
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|
Term
| How is phosphorylation a molecular switch? |
|
Definition
| It is a switch because phosphates can be added and taken away, thus turning signals off or on. |
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|
Term
| How is calcium a handy 2nd messenger? |
|
Definition
| It plays an important role in signal transduction pathways, in neurotransmitter release from neurons, contraction of all muscle cell types, and fertilization. |
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Term
| How are receptors specific? |
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Definition
| Each receptor is specific for a specific ligand. |
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Term
| How does cell achieve cross-talk? |
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Definition
| The cell integrates information from multiple signals to initiate an appropriate response. |
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Term
| How does cell achieve amplification? |
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Definition
By converting a small signal into a large response.
Ex. Local mediators, autocrine signaling, etc. |
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Term
|
Definition
Calcium binding protein
Calmodulin binds to calcium = conformation change. now it can recognize target |
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Term
|
Definition
| A G-Protein coupled light receptor; uses light as 'ligand' |
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Term
| Steps in Rhodipsin signaling sequence |
|
Definition
1. GPCR Rhodopsin is activated by light
2. Activate g-protein transducin
3. Sets off signaling cascade
4. Causes ion channels to close
5. Voltage change neurotransmitters released |
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|
Term
How could you turn off RAS?
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|
Definition
1. Hydrolyze GTP
2. Dephosphrylate the signal
3. Take away signal molecule |
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|
Term
| Akt signaling ________ apoptosis |
|
Definition
|
|
Term
Rapamycin _______ TOR involved in __________
|
|
Definition
|
|
Term
| JAK-STAK Pathway in Milk Production |
|
Definition
Two Jaks phosphorylate and change conformation
phosphorylates receptor
recognized by STAT
Jak phosphorylates STAT
turns on transmission of milk production protein |
|
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Term
|
Definition
In absence of ethylene destroyed
Presence of ethylene turns on responsive genes
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|
Term
Determine function in insulin response
|
|
Definition
- Knockout/knockdown/make a mutant
- View affects on insulin production
|
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|
Term
You think your sequence turns on transcription
|
|
Definition
- Western blot for protein expression
- RT PCR = Measure RNA being transcribed
- Bioinformatics
- DNA microarray |
|
|
Term
RAS interacts with partners – how does it?
|
|
Definition
- Tag specific proteins
- Assay – Coimmunoprecipitation
- Measure P target |
|
|
Term
What if RAS was always active?
|
|
Definition
- unregulated cell cycle, cell growth proliferation, no regulation
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