Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Year 2 - Committy 1 - Biochemistry > 2- Biochemistry of Epithelial Tissue > Flashcards

2- Biochemistry of Epithelial Tissue Flashcards

1
Q

Where are simple squamous tissues found and what’s their function?

A

1-lines of blood vessels and air sacks of lungs
2-permits exchange of nutrients, wastes and gases

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

Where are the stratified squamous tissues found and what is their function?

A

1-outer layer of skin mouth vagina
2- protect against abrasion (wear down), drying out and infection

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

Where are the simple cuboidal tissue and what is its function?

A

1-lines, kidney tube and glands
2- it’s a secretes and absorbs water and small molecules

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

Where is the stratified cuboidal tissue and what is it is function?

A

1-it lines the ducts of sweat glands
2-it’s secrets water and ions

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

Where is the of the simple columnar Tissue and what is it is function?

A

1-it lines most of the digestive organs. 2-it absorbs nutrients and produces mucus.

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

Where is the stratified colonial tissues and what is it is function?

A

1- it lines the epididymus, mammary glands and the larynx

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

What is the cytoskeleton?

A

It is a network of filamentous proteins which dynamically organized the interior of the living cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the 3 functions of the cytoskeleton?

A

1- maintain cell shape
2- anchor organelles
3- Enable cell movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How dose the cytoskeleton look like under the light micrograph ?

A

The microtubles are green and the microfilaments are blue where the intermediate filaments from most of the rest of the network.

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

What are the three types of fibers of the cytoskeleton ?

A

1- microtubules ( an insoluble polymers of tubulin ). 2- microfilaments ( insoluble polymers of actin ). 3- intermediate filaments ( insoluble keratin )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are microtubules ?

A

They are cylindrical tubes, 20-25 nm in diameter

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

What are microtubules made from ?

A

It is composed of subunits of the protein tubulin

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

What is the function of microtubules ?

A

They determine the cell shape and its involved in the transport of material within cells .

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

Where do microtubules come from ?

A

They come from spindle fibers for separating chromosomes during mitosis

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

What is microtubules used for ?

A

It is used for locomotion when arranged inside flagella and cilia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are microfilaments ?

A

It is a fine, thread like protein fibers 3-6 nm in diameter .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are microfilaments made from ?

A

They are composed of contractile protein ( actin ), the most abundant protein in a cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the function of microfilaments ?

A

Microfilaments are responsible for muscle contraction in association with myosin

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

What dose microfilaments carry out ?

A

They carry out cellular movements including contraction and cytokinesis

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

What are intermediate filaments ?

A

They are about 10 nm diameter and provide tensile strength for the cell, they are the strongest filaments of the cytoskeleton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What dose the fibers in the intestinal epithelial cells do ?

A

1- microfilaments project into the villi, giving shape to the cell surface.
2- microtubules grow out of the centrosome to the cell periphery.
3- intermediate filaments connect adjacent cell through desmosomes.

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

What is keratin ?

A

It os an intermediate filament

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

Where is keratin synthesized ?

A

It is synthesized in keratinocytes .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the structure of keratin ?

A

It has a fibrous structure .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are the characteristics of keratin ?
It is stable, mechanically durable and insoluble .
26
What dose keratin form ?
It forms hard and robust structures like scale, teeth and horns
27
What are the two types of keratin ?
Alpha ( a- ) and beta ( B- ) keratin
28
Alpha keratin in mammals are the main components of what ?
Hair and wool
29
What dose Alpha-keratin contain what dose it form ?
Alpha-keratins it contains a hydrophilic amino acid in large amounts, they form left-handed superhelix structures.
30
What dose Beta-keratins do in birds and reptiles ?
It takes place in feather, skin, claw and beaks.
31
What is the structure characteristics of keratin ?
Keratin has many repeated heptapeptide motifs in its primary structure, these motif has three hydrophobic amino acids.
32
How many protein chains dose microfibril / intermediate filament ?
They contain 32 protein chains, each chain has is a dime.
33
What is damage of a perm to keratin in the hair ?
The chemical procedures affect structure of keratin as a rearrangement of disulfide bonds may cause structural damage to keratin.
34
What happens in the epidermolysis bullosa simplex (EBS) ?
The mutations in KRT5 or KR14 gene prevents the keratin proteins from assembling into strong networks causing cells in the epidermis to become fragile and easily damaged.
35
How are epidermal cells are easily broken ?
To form separated layers due to a defective keratin filaments as a result the skin is less resistant to friction and minor trauma and blisters easily.
36
What type of allele is EBS and how many people dose it effect ?
It is an autosomal dominant allele and it affects 1 in every 30,000 to 50,000.
37
What is the epidermal permeable barrier ?
It is a multilayered epithelium that protects the organism from the environment.
38
What is the function of the epidermal permeability barrier ?
The barriers function in human epidermis depends on the transglutaminase-mediated cross-linking of structural proteins and lipids .
39
What are Transglutaminases (TGases) ?
It is a protein cross-linking (a post-translational modification) enzymes, its a Ca++ dependent.
40
What dose the TGases do ?
Its from an interprotein cross-links that hold proteins together and play a key role in the formation of cross-linked cornfield envelopes during keratinocyte terminal differentiation ( formation of corneocytes ).
41
What dose TGases catalyze ?
It catalyze the formation of the isopeptide bond between the carboxamido group of protein-bound glutamine in one protein and lysine residue of other protein. The reaction product is a stable and insoluble macromolecule .
42
What is the mutation of keratinocyte transglutaminase 1 (TGM1) ?
The TGM1 cause lamellar ichthyosis, its a severe congenital skin disorder characterized by generalized large scale and variable redness.
43
What is the TGM1 is involved in ?
The TGM1 is involved in the formation of the cornfield cell envelope.
44
What dose the mutation in the TGM1 cause ?
It causes defects in the intercellular lipid layers in the stratum corneum leading to defective barrier function of the stratum corneum and to the ichthyotic phentotype.
45
What is the lamellar ichthyosis ?
It is a rare autosomal recessive disorder where a baby born covered with a transparent membrane (sheds within 1-14 days) revealing generalized scaling with redness of the skin.
46
What is melanin ?
It is a 5,6-dihydroxyindole polymer its synthesized from tyrosine, its insoluble in large molecule, its synthesized in specified organelles (melanosomes) of melanocyte ( skin and hair follicles ).
47
What is the amount of melanin synthesized in melanosomes correlate to ?
The skin and hair color
48
What is the function of the dendrites of melanocytes ?
They are placed among the keratinocytes like an octopus and transfer the melanosome content to keratinocytes .
49
What are the two types of melanins ?
1- Eumelanin 2- Pheomelanin
50
What is Eumelanin ?
It is the most common form of the biological melanin, a brown-black polymer of dihydroxyindole carboxylic acids and their reduced forms .
51
What is the pheomelanin ?
Its the other form of melanin is where a cysteine-containing red - brown polymer of the benzothiazine units largely responsible for red hair and freckles.
52
What happens when the melanosomes are transferred to keratinocytes ?
They from perinuclear protective cap over the nucleus, this cap helps protect the nuclear DNA from damaging effects of UV radiation .
53
What happens when the melanosomes are transferred to keratinocytes ?
They from perinuclear protective cap over the nucleus, this cap helps protect the nuclear DNA from damaging effects of UV radiation
54
What is albinism ?
Albinism is an autosomal recessive genetic disorder characterized by the complete or partial absence of melanin in the skin, hair and eyes due to absence or defect of tyrosinase.
55
What is the name of patients with complete absence of pigment ?
Albino
56
What is oculocutaneous albinism ?
Its the common form of albinism which involves both eyes and skin.
57
What is a gland ?
A gland is an organ is an animal body that synthesizes a substance for release of substances
58
What dose the mammalian stomach secrete ?
Its a highly acidic gastric juice ( 0.1M HCL)
59
What secrets hydrophobic acid ?
They are secreted by partial cells located by parietal cells located in gastric mucosa.
60
How many alveoli dose lungs have ?
2-3 million alveoli
61
What are the two types of epithelial cells that the alveolar wall consist of ?
1- Type I : alveolar cells are thin and flat, they are responsible for gas transport. 2- Type II : alveolar cells that are round and secret surfactant .
62
What is the composition of surfactant ?
90% lipids and 5-10% surfactant-specific proteins
63
What are surfactant ?
It is a surface-active agent.
64
What is the function of surfactant ?
It increases pulmonary compliance where the lung ability to stretch and expand
65
What is the role of surfactant during inspiration ?
When the alveoli expand the surfactant molecules move apart .
66
What is the role of surfactant during expiration ?
When the lungs molecules move together and become concentrated the surface tension is reduced.

Year 2 - Committy 1 - Biochemistry (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions