CH 10 Cell Form and Function Reading Guide Flashcards
Define organ
Two or moser tissues working together to perform a function
What are the four basic tissue types
Epithelial, connective, nervous and muscle
What tissue type make up the heart
Muscle tissue to constrict, nerve tissue to conduct electrical impulses
What are the two main tissue layers of the skin? What aRe the main cell types in each?
Epidermis and dermis epidermis is made up of keratinocytes and melanocytes Dermis is made up of connective tissue main cells being fibroblasts
What structure separates the epidermis from the dermis?
The basal lamina
What are the main differences between the dermis and epidermis?
Epidermis made up of epithelial tissue, serves as water resistant and protective barrierDermis made up of connective tissue, has several nerve, sweat glands, veins and arteries
Why cytoskeletal types are universal among all eukaryotic cells?
Microtubules and micro filaments animal cells also have intermediate filaments
What do all three cytoskeletal types have in common?
Long chains made up of protein sub units
How are microtubules and micro filaments similar?
Both formed of circular monomers where microtubules are form by tube of Tubulin dimer
How are micro filament and intermediate filaments similar in structure?
Longer interwoven chains
What do centre some have to do with microtubules and micro filaments?
Organize the arrangement of the microtubules and micro filaments
Where are micro filaments located within the cell and what is there main function?
Located in the area just beneath the cell membrane. Used to provide structural support
Why are micro villi useful for the function of intestinal epithelial cells?
Good at absorption due to there large surface area
Hoe does micro filament enable the structure of micro villi?
Provide rigid column structure down the Center of the micro villi
What subunits make up the microtubules fibre?
Alpha and beta Tubulin
How does the centrosome relate to microtubules?
It is the organizing centres that arrange the microtubules Also form spindle apparatus that separates replicated chromosomes during cell division
How are microtubules involved in transport and movement?
They can be found in arrangements of cilia and flagella
Define cilia?
Hair like microtubules that cover the exterior of the cell
Define flagella
Tail like microtubules that whip to propel the cell
What is an exampl of a human cell that have cilia or flagella?
Cilia: found in the lungs to push mucus outFlagella: sperm cells used to swim
What is the role of microtubules during mitotic cell division?
Separates replicated chromosomes
What are the subunits that make up microfilaments?
Actin monomers
Where in the cell are microfilaments most likely to be found?
Are locate just beneath the cell membrane
How do microfilaments provide structural support for micro villi?
Microfilaments make up the micro villi Longer bundles form bands that extend the circumference of the cell
How are intermediate filaments different from microfilaments and microtubules?
There diameter is intermediate to microtubules and microfilamentsLamins can be found inside the nucleus and provide support for the nuclear envelop
What are four types of intermediate subunits?
In epithelial cells these are keratinIn fibroblasts they’re VimentinsNeurofilaments in neutronsLamins in cell nucleus
What is the intermediate filament associated with the epithelial cells of the epidermis?
Keratins Used to protect underlying tissue
Where else in the body besides the epidermis can keratin intermediate filaments be found?
Lining of the intestine
What’s the sub cellular localization of intermediate filaments?
Surrounding and within the nucleus
Define dynamic instability
Microtubules undergo a random cycles of rapid shrinkage and slower growth
What is the + and - end of the micro tubules and microfilaments?
The + end is the fast growing end the - end is slow growing
Do subunits only add and subtract from their respective ends?
Yes + adds and - subtracts
Why is it useful to the cell that microtubules and microfilaments are in a constant state of growth and shrinking?
Allows for rapid growth which becomes important in cell division
What are the three type of movement a cell can do?
Relocation, change shape, movement of molecules from outside to inside the cell and around the inside of the cell
Do intermediate filaments have motor proteins?
No
Define a motor protein
Cause muscle contraction of actin within microfilaments inside muscle cell
What’s the fuel that drive motor protein movement and where is the majority of this fuel produced in the cell?
ATP found in myosin
Which motor protein associates with microfilaments and does this protein have directional movement?
Myosin yes has a shortening movement
How are myosin and kinesin different?
Myosin binds to microfilaments and kinesin binds to microtubules
Which end to kinesins and dyenins go to?
Kinesins go to the + Dyenins to the -
How are cilia different from micro villi?
Cilia are made up microtubules cores while micro villi structure is supported by microfilaments
Give an example of a crawling cell?
White blood cell chasing down foreign bacteria
What type of cytoskeletal component is important for cell crawling?
Microfilaments
Why do sponge cells from different sponges not mix together?
Due to different cadherins within the sponge cells associating only with its specific sponge
What did j holtfreters experiment show that h v Wilson’s did Not?
That there are associated cadherins for different types of tissues. Ex. E-cadherins for epidermal cells
Compare and contrast cadherins and integrins?
Cadherins are transmembrane proteins that connect cells to other cellsIntegrins are transmembrane proteins that connect cells to the extra cellular matrix
Which types of cytoskeletal types are involved in adheren junctions and desmosomes?
Adheren junctions: cadherins bonded to microfilamentsDesmosomes: cadherins bonded to intermediate filaments
What is the difference between hemidesmosome and desmosomes?
Hemidesmosome: use integrin to bind basal lamina to intermediate filaments (cell to connective tissue)Desmosomes: use cadherins binded to intermediate filaments (cell to cell)
How are integrins and hemidesmosome different?
Integrins bind to microfilaments in the cell where hemidesmosomes bind to intermediate filaments in the cell
What is a tight junction?
Junctional complexes that seal between cells so that travel between cells must be mitigated by cellular transport mechanisms
Do tight functions provide a lot of tensile strength, is it enough for epithelial cells to adhere to each other using tight junctions?
No There function is to prevent passage of material between cells not to anchor them
How can bands of tight junctions establish different regions of the cell?
Tight junctions can form regions of the cell which can prevent different molecules from diffusing from one end to the other
How are gap junctions different from tight junctions?
Gap junctions allow for material to pass between cell membranes. There not used to anchor cells to other cells
Where is the ECM located and how is it made?
Located in connective tissues to provide support and protection.It is synthesized, secreted and maintained by many types of cells
What basic types of molecules is the ECM made of?
Proteins and polysaccharides
What are some of the fibrous types of proteins found in the ECM?
Collagen, elastin and laminin
If we compared the ECM to a concrete what components would be the rebar and what components would the masonry?
Rebar would be the collagen, elastin and laminin fibresThe masonry would be the gel like polysaccharide matrix
How is collagen similar to and different from intermediate filaments?
Similar: long fibrous molecules formed into bundlesDifferent: triple helix structure
What are fibroblasts and where can they be found?
A cell found in connective tissue that synthesizes collagen and the ECM
Where do you find basal lamina and what is their function?
It is found at the base of all epithelial cellsProvides structural base of support
Is the basal lamina made up of cells of by an ECM made of cells?
ECM as it contains collagen
How are epithelial cells anchored to basal lamina, what cellular junction type is involved and what cell adhesion proteins are used?
Anchored by hemidesmosomesCell junction?Cell adhesion involves intermediate filaments and integrin
Define malignant
Cn mestastize meaning break away from the main tumor and colonize distant cells
Define benign
Tumours that are encapsulated and continuously divide because regulation of cell division has gone weary
Why do some cells take on a flat shape or a three dimensional shape?
It depends on what matrix they’re grown on the cell will grow to Maxine it adhesions to the matrix
Define a tissue
A biological collection of cells that work together to perform a specific function
