Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biol 130 > Module 10: Cell and Tissue Form > Flashcards

Module 10: Cell and Tissue Form Flashcards

1
Q

In a multicellular organism cell come together to form…

A

tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

a collection of cells work together to perform a …

A

specific function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Two or more tissues combine and function together to make up an…

A

organ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The shape of cells and organs reflects what?

A

their function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Function is determined and maintained by…

A

structural protein networks in the cytoplasm
- also called the cytoskeleton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the two main layers of skin?

A

Epidermis: the outer layer that serves as a water resistant and protective barrier
Dermis: the layer beneath the epidermis supports the epidermis and supplies it with nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The structural integrity of a tissue or organ depends on the ability of the cells:

A
  • to adhere to one another via cellular junctions
  • to adhere to a meshwork of proteins and polysaccharides outside the cell called the extracellular matrix (ECM)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Connective Tissue

A
  • provides structure and support
  • the dermis supports the epidermis
  • the dermis is mostly made up of connective tissue, a lot of ECM
  • the main cell type found in the dermis is fibroblast, produces the extracellular matrix
  • also contains nerves and blood vessels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Epithelial tissue

A

covers the outside of the body and lines many internal structures of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The Epidermis

A
  • primarily composed of epithelial cells called keratinocytes, specialized to protect underlying tissues and organs
  • contains melanocytes that produce the pigments of skin
  • the basal lamina, supports the epithelial cells
    – a specialized ECM below the bottom layer of the epidermis
  • supports the epithelial cells
  • the bottom layer of keratinocytes are attached to the basal lamina, cell junctions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Protein fibers of the cytoskeleton provide what?

A

internal support for cells, like bones provide internal support for the whole body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the cytoskeleton formed from?

A

long chains of protein subunits joined together
- they provide structural support and enable the movement of substances within cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

All eukaryotic cells have at least two cytoskeletal elements, what are they?

A

Microtubules and Microfilaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What cytoskeletal element do animals also have?

A

intermediate filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Microtubules Makeup

A
  • tubelike structures made of polymers of protein dimers
  • each dimer are made of 2 tubulin proteins
    – alpha tubulin
    – beta tubulin
  • one alpha tubulin and one beta tubulin combine to form tubulin dimer
    – these dimers assemble to form microtubules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Microtubule Function

A
  • microtubules found in animal cells radiate outward to the cell periphery
    – they form at the centrosome
  • this arrangement helps maintain the cells shape and allows it to withstand compression
    – many organelles are secured to microtubules, guides the arrangement of organelles in the cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Microfilaments Makeup and Location

A
  • polymers of actin monomers that are arranged into a helix
  • thinnest of the cytoskeletal fibers
  • relatively short and extensively branched just beneath the cell membrane of a cell
  • reinforce the cell membrane and organize the proteins associated with it
  • present in various locations in the cytoplasm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Epithelial cells of the small intestine contain ____ on their surface. Within the ______ are bundles of _________

A

microvilli
microvilli
microfilaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What do microfilaments form in epithelial cells?

A

they form a band of longer filaments that extends around the circumference of epithelial cells
- the band provides structural support to the individual epithelial cells as well as the entire layer of epithelial cells
- the band is attached to a cell junction that connect neighbouring cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Microfilaments also take part in what three things?

A
  1. transport of materials inside cells
  2. shortening of muscle cells during contraction
  3. separation of daughter cells at the end of animal cell division
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Microtubules and Microfilaments are always _____
how?

A

changing
- become longer by adding subunits
or shrink by losing subunits
- these polymers grow faster at one end then the other
– faster growing end is the plus end
– slower growing end it the minus end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which end is the microtubule positioned at the organizing center of the chromosome?

A

the minus end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Microtubules undergo random cycles of…..

A
  • rapid shrinkage, depolymerization
  • slower growth, polymerization
24
Q

What is the cycle of polymerization and depolymerization in microtubules know as?

A

Dynamic Instability

25
Q

a dramatic shrinkage in a microtubule results in what?

A

microtubule catastrophe

26
Q

Dynamic instability in microtubules allows for what?

A

allows cells to rapidly re-organize the cytoskeleton when needed
- microtubules explore the space of the cell by growing into new areas and then shrinking back
- for example, spindle microtubules use this process to quickly find and attach to chromosomes during cell division

27
Q

Microtubules and microfilaments ca be joined by small accessory proteins called…

A

motor proteins

28
Q

Microtubules function as tracks for transport within the cell. What two motor proteins associate with the tracks? How are they powered?

A
  1. Kinesin moves the cargo toward the microtubules plus end
  2. Dynein moves the cargo towards the microtubules minus end
    - the energy for this movement is driven by conformational changes in the motor proteins and is powered by ATP
29
Q

Microtubules are found in structures that propel the movement of…

A

cells, flagella
- substances surrounding cells, cilia
- in cilia and flagella microtubules associate with the motor proteins dynein that causes movement

30
Q

Intermediate filaments

A
  • found in animal cells
  • diameter is intermediate to microfilaments and microtubules
  • provide mechanical strength to the cell
  • form strong cable like polymers of proteins
31
Q

Types of Intermediate Filaments

A
  • more then 100 different types of intermediate filaments
  • made up of different proteins depending on the cell type
    for example
  • epithelial cells, keratin
  • fibroblasts, vimentins
  • neurons, neurofilaments
  • nucleus, Lamins
32
Q

What do multicellular organisms use cell junctions for?

A

to physically connect one cell to another cell or to the ECM

33
Q

Cells exhibit polarity because of…

A
  • differences between one side and the other
  • spatial differences in shape structure and function within a cell
34
Q

For epithelial cells if its facing out side body or lumen it is….

A

apical (top side)

35
Q

For epithelial cells if its attached to the basal lamina it is….

A

basal (bottom, base)

36
Q

Cadherins

A
  • integral transmembrane glycoproteins for cell-to-cell attatchment
37
Q

How do Cadherins work?

A
  • the extracellular domain of a cadherin molecule binds to the extracellular domain of a cadherin of the same type on an adjacent cell
  • the cytoplasmic part of the cadherin is linked to the internal cytoskeleton (attached to the microfilament sometimes)
38
Q

How do cadherins help with structure?

A
  • provides structural continuity from the cytoskeleton of one cell to the cytoskeleton of another
  • increase the strength of tissues and organs
39
Q

Integrins

A
  • internal transmembrane glycoproteins for cells to attach to ECM
  • cytoplasmic domain interacts with the ECM, important for the structural integrity of tissues under physical stress
40
Q

Cell junctions do what?

A
  • connect cells to other cells or to the basal lamina and are reinforced by the cytoskeleton
41
Q

What are the five types of cell junctions?

A
  1. Adherens junctions
  2. Desmosomes
  3. Hemidosmosomes
  4. Tight junctions
  5. Gap junctions
42
Q

Cadherins are found in which two cell junctions?

A

adherens junctions and desmosomes

43
Q

Adherens Junctions

A
  • a belt-like junctional complex of cadherins that goes around the circumference of the cell

Intracellularly
- the belt of cadherins attaches to a band of actin microfilaments in the cytoplasm

extracellularly
- the cadherins in adjacent cells attach to each other

  • creates stability
44
Q

Desmosomes

A
  • button-like points of adhesion that hold the cell membrane of adjacent cells together
  • cadherins strengthen the connection between cells
  • the cadherins in the desmosomes of one cell binds to the cadherins in the desmosomes of adjacent cells
  • the cytoplasmic domains of cadherins are linked to intermediate filaments of the cytoskeleton
45
Q

Hemidesmosomes

A
  • epithelial cells are firmly anchored to the basal lamina
  • attached via a structure similar to desmosomes called hemidesmosomes
  • integrins are the most prominent cell adhesion molecules in hemidesmosomes
  • the extracellular domains of integrins bind to the ECM proteins in the basal lamina
  • the cytoplasmic domains of integrins are linked to intermediate filaments of the cytoskeleton
46
Q

Tight Junctions

A
  • since adherens junctions & desmosomes do not prevent the passage of materials between the cells, they need another mechanism to prevent the movement of materials
  • tight junctions are able to seal the extracellular space
  • the only way a substance can travel from one side of a sheet of epithelial cells to the other is by moving through the cells by means of a cellular transport mechanism
47
Q

Gap Junctions

A
  • Cell-to-cell communication
  • extremely small channels (connexons) span a small gap (2-4 nm) between cells
  • connexons allow for cytoplasmic continuity between adjacent cells, but only low molecular weight material can pass between cells (really fast)
    – like ions
  • integrate activities of individual cells of a tissue
48
Q

Plasmodesmata

A
  • specific to plants
  • allow plant cells to transfer RNA molecules and proteins
  • much larger than gap junctions
  • the cell membranes between the two cells are continuous, allow plants to send signals to one another despite being enclosed within rigid cell walls
49
Q

What is the the ECM?

A
  • the layer of material secreted beyond the region of the cell membrane in the extracellular area
  • formed from insoluble meshwork of proteins and polysaccharides
50
Q

What are the two general functions of the ECM?

A
  1. act as a supportive protective material
  2. allow for expression of different cell functions
51
Q

Plant ECM Composition

A
  • the ECM is the layer of material secreted beyond the region of the cell membrane in the extracellular area
52
Q

What is the cell wall?

A

a type of extracellular matrix

53
Q

What are the three layers of the plant ECM/cell wall?

A
  1. middle lamella
    - made of carbohydrates
    - main mechanism by which plant cells adhere to one another
  2. primary cell wall
    - thin and flexible
    - made of cellulose fibers, pectin, and several other proteins
  3. secondary cell wall
    - rigid
    - made of cellulose and lignin, hardens the cell wall and makes it water-resistant
54
Q

Animal ECM Composition

A
  • the connective tissue of animals is extensive in ECM
  • a mixture of proteins and polysaccharides secreted by cells
  • it is composed of large fibrous proteins, including collagen, elastin and laminin
  • these proteins are found in the gel-like polysaccharide matrix
55
Q

Collagen

A
  • most abundant protein in the animal ECM
  • most abundant animal protein, 1/4th of the protein in the body
  • more than 20 different forms of collagen exist
  • type 1 collagen is the most abundant
  • found in the dermis of human skin it provides support
  • composed of intertwined fibers that make it stronger than if it were a single fiber of the same diameter
  • it consists of three polypeptides wound around one another
  • forms a triple helix
  • a bundle of these molecules forms a fibril, with fibrils then being assembled into fibers
56
Q

Basal Lamina

A
  • the basal lamina is a specialized layer of the extracellular matrix that is present beneath all the epithelial tissues
  • it provides a structural foundation for epithelial tissues
  • consists of several proteins, including a type of collagen
  • provides flexible support
  • acts as a scaffold for other proteins to assemble on

Biol 130 (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions