Fibrous proteins like collagen and elastin provide structural functions. Collagen is abundant in skin, tendons, and the cornea. It forms fibrils with a characteristic triple helix structure. Variations in collagen types are due to differences in their alpha chain sequences. Defects in collagen synthesis can cause connective tissue disorders like Ehlers-Danlos syndrome and osteogenesis imperfecta.
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Join live classes, download study aids, sell your documents, join or host your own classes online, get tutoring, tutor students, take practices tests and more at Examville.com
Collagen is the most abundant protein in your body. It is the major component of connective tissues that make up several body parts, including tendons, ligaments, skin and muscles (1). Collagen has many important functions, including providing your skin with structure and strengthening your bones (
Collagen /certified fixed orthodontic courses by Indian dental academy Indian dental academy
Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
The Biology of the Basement Membrane Zone Ibrahim Farag
It is a critical interface between the epidermis and dermis and is a highly specialized structure that allows for communication between different cell types.
Examination of BMZ/Structure of BMZ/Origin of BMZ/Function of BMZ/Examples of Some diseases affecting BMZ
Biochemistry of musculoskeletal system. biochemistry of MSS prepared by Fikad...fikaduseyoum1
biochemistry of MSS prepared by Fikadu Seyoum Tola. This ppt essentially discuss about collegen biosnthesis, defect and muscle energy metabolism with its regulations.
Collagen is the most abundant protein in your body. It is the major component of connective tissues that make up several body parts, including tendons, ligaments, skin and muscles (1). Collagen has many important functions, including providing your skin with structure and strengthening your bones (
Collagen /certified fixed orthodontic courses by Indian dental academy Indian dental academy
Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
The Biology of the Basement Membrane Zone Ibrahim Farag
It is a critical interface between the epidermis and dermis and is a highly specialized structure that allows for communication between different cell types.
Examination of BMZ/Structure of BMZ/Origin of BMZ/Function of BMZ/Examples of Some diseases affecting BMZ
Biochemistry of musculoskeletal system. biochemistry of MSS prepared by Fikad...fikaduseyoum1
biochemistry of MSS prepared by Fikadu Seyoum Tola. This ppt essentially discuss about collegen biosnthesis, defect and muscle energy metabolism with its regulations.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Biochemical and clinical aspects of collagenrohini sane
A comprehensive presentation on Biochemical and clinical aspects of Collagen for MBBS, BDS, B Pharm & Biotechnology students to facilitate self- study.
Collagen is most abundant protein in mammals, the main fibrous component of skin, bone, tendon and cartilage.
Collagen comprises one- third of the total protein, accounts for three-quarters of the dry weight of skin, and is the most prevalent component of the extracellular matrix.
The collagen family consists of 28 members and these are classified by Roman numbers on the basis of their chronology of discovery.
Collagen / /certified fixed orthodontic courses by Indian dental academy Indian dental academy
Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
3. - Collagen and elastin, well-characterized fibrous
proteins of the extracellular matrix that serve structural
functions in connective tissues of the body and Keratine
in ectodermal tissues skin,nails,hair,horn,hoof of animals.
- Collagen and elastin, found as components of skin,
connective tissue, blood vessel walls, and sclera and
cornea of the eye.
- Fibrous protein exhibits special mechanical properties,
resulting from its unique structure, which are obtained by
combining specific amino acids into regular, secondary
structural elements.
- This is in contrast to globular proteins, whose shapes are
the result of complex interactions between secondary,
tertiary, and, sometimes, quaternary structural elements.
4. COLLAGEN
-Collagen is the most abundant protein in the
human body.
-A typical collagen molecule --- long, rigid
structure in which three polypeptides (referred to
as “α chains”) are wound around one another in
a rope-like triple helix
5. Although these molecules are found throughout
the body, their types and organization are
dictated by the structural role collagen plays in a
particular organ.
- Gel like structure: Vitreous humor
- Tight parallel structure: Tendon
- Stacked transparent structure: Cornea
- Arranged at an angle: Bone
6. Types of collagen
• The collagen superfamily of proteins includes more than
25 collagen types, as well as additional proteins that have
collagen-like domains.
• The three polypeptide α chains are held together by
hydrogen bonds between the chains.
• Variations in the amino acid sequence of the α chains result
in structural components that are about the same size
(approximately 1,000 amino acids long), but with slightly
different properties.
• These α chains are combined to form the various types of
collagen found in the tissues.
• most common collagen, type I, contains two chains called
α1 and one chain called α2 (α12α2), whereas type II
collagen contains three α1 chains (α13).
7. The collagens can be organized into three
groups, based on their location and
functions in the body
•
Most abundant type of Collagen
8. 1. Fibril-forming collagens: Types I, II, and III are the fibrillar
collagens, and have the rope-like structure for a typical
collagen molecule.
In the electron microscope, these linear polymers of fibrils have
characteristic banding patterns, reflecting the regular staggered
packing of the individual collagen molecules in the fibril
.
9. - Type I collagen fibers are found in supporting
elements of high tensile strength (for example,
tendon and cornea), whereas fibers formed from
type II collagen molecules are restricted to
cartilaginous structures.
- The fibers derived from type III collagen are
prevalent in more distensible tissues, such as blood
vessels
10. 2. Network-forming collagens: Types IV and VII
form a three-dimensional mesh, rather than distinct
fibrils. For example, type IV molecules assemble into a
sheet or meshwork that constitutes a major part of
basement membranes.
Electron micrograph of a polygonal
network formed by association of
collagen type IV monomers.
11. 3. Fibril-associated collagens: Types IX and XII
bind to the surface of collagen fibrils, linking these
fibrils to one another and to other components in
the extracellular matrix
12. Structure of collagen
1. Amino acid sequence:
- Collagen is rich in proline and glycine, both of which are important in the
formation of the triple-stranded helix.
- Proline facilitates the formation of the helical conformation of each α chain
because its ring structure causes “kinks” in the peptidechain.
(The presence of proline dictates that the helical conformation of the α chain
cannot be an α helix.)
- Glycine, the smallest amino acid, is found in every third position of the
polypeptide chain.
- Glycine fits into the restricted spaces where the three chains of the helix
come together.
- The glycine residues are part of a repeating sequence, –Gly–X–Y–,
where X is frequently proline and Y is often hydroxyproline (but can be
hydroxylysine.
- Thus, most of the α chain can be regarded as a polytripeptide whose
sequence can be represented as (–Gly–Pro–Hyp–)333.
13. 2. Triple-helical structure:
Unlike most globular proteins that are folded into
compact structures, collagen, a fibrous protein, has an
elongated, triple-helical structure that places many of
its amino acid side chains on the surface of the triple-
helical molecule.
Note: This allows bond formation between the exposed
R-groups of neighboring collagen monomers, resulting
in their aggregation into long fibers.
14. 3. Hydroxyproline and
hydroxylysine: - Collagen contains
hydroxyproline (hyp) and
hydroxylysine (hyl), which are not
present in most other proteins.
- These residues result from the
hydroxylation of some of the proline
and lysine residues after their
incorporation into polypeptide
chains. - The hydroxylation is, thus,
an example of posttranslational
modification.
- Hydroxyproline is important in
stabilizing the triple-helical structure
of collagen because it maximizes
interchain hydrogen bond formation.
15. ELASTIN
In contrast to collagen, which forms fibers that are
tough and have high tensile strength, elastin is a
connective tissue protein with rubber-like
properties.
- Elastic fibers composed of elastin and glycoprotein
microfibrils are found in the lungs, the walls of large
arteries, and elastic ligaments.
- They can be stretched to several times their normal
length, but recoil to their original shape when the
stretching force is relaxed.
16. Structure of elastin
- Elastin, insoluble protein polymer synthesized from a precursor,
tropoelastin, a linear polypeptide composed of about 700 amino
acids that are primarily small and nonpolar (for example, glycine,
alanine, and valine).
- Elastin also rich in proline and lysine, but contains only a little
hydroxyproline and hydroxylysine.
- Tropoelastin secreted by the cell into the extracellular space.
- There it interacts with specific glycoprotein microfibrils, such as
fibrillin, which function as a scaffold onto which tropoelastin is
deposited.
- Some of the lysyl side chains of the tropoelastin polypeptides are
oxidatively deaminated by lysyl oxidase, forming allysine residues.
- Three of the allysyl side chains plus one unaltered lysyl side chain
from the same or neighboring polypeptides form a desmosine
cross-link
17. This produces elastin—an extensively interconnected, rubbery
network that can stretch and bend in any direction when
stressed, giving connective tissue elasticity
18. Biosynthesis of collagen
- The polypeptide precursors of the collagen
molecule are formed in fibroblasts (or in the
related osteoblasts of bone and chondroblasts
of cartilage), and are secreted into the
extracellular matrix.
- After enzymic modification, the mature
collagen monomers aggregate and become
cross-linked to form collagen fibers.
19. 1. Formation of pro-α chains: Collagen is one of many proteins that
normally function outside of cells. Like most proteins produced for
export, the newly synthesized polypeptide precursors of α chains
(prepro-α chains) contain a special amino acid sequence at their
N-terminal ends. (signal sequence )
The signal sequence is rapidly cleaved in the
RER to yield a precursor of collagen called a pro-α chain.
20. 2. Hydroxylation:
- The pro-α chains are processed by a
number of enzymic steps within the
lumen of the RER while the polypeptides
are still being synthesized .
- Proline and lysine residues found in the
Y-position of the –Gly–X–Y– sequence
can be hydroxylated to form
hydroxyproline and hydroxylysine
residues.
- These hydroxylation reactions require
molecular oxygen, Fe2+ and the reducing
agent vitamin C, without which the
hydroxylating enzymes, prolyl
hydroxylase and
lysyl hydroxylase, are unable to function
21. • 3. Glycosylation: Some hydroxylysine residues are modified
by glycosylation with glucose or glucosyl-galactose
• 4. Assembly and secretion:
- The formation of procollagen begins with formation of
interchain disulfide bonds between the C-terminal extensions
of the pro-α chains.
- This brings the three α chains into an alignment favorable
for helix formation.
- The procollagen molecules move through the Golgi
apparatus, where they are packaged in secretory vesicles.
- The vesicles fuse with the cell membrane, causing the release
of procollagen molecules into the extracellular space.
22. 5. Extracellular cleavage of procollagen molecules:
- After their release, the procollagen molecules are
cleaved by N- and C-procollagen peptidases, which
remove the terminal propeptides, releasing triple-helical
tropocollagen molecules.
6. Formation of collagen fibrils:
- Individual tropocollagen molecules spontaneously
associate to form collagen fibrils.
- They form an ordered, overlapping, parallel array, with
adjacent collagen molecules arranged in a staggered
pattern, each overlapping its neighbor by a length
approximately three-quarters of a molecule
23. 7. Cross-link formation:
- The fibrillar array of collagen molecules
serves as a substrate for lysyl oxidase.
- This Cu2+ containing extracellular enzyme oxidatively
deaminates some of the lysyl and hydroxylysyl
residues in collagen.
- The reactive aldehydes that result (allysine and
hydroxyallysine) can condense with lysyl or
hydroxylysyl residues in neighboring collagen
molecules to form covalent cross-links and, thus,
mature collagen fibers
24.
25.
26.
27. Collagen diseases: Collagenopathies
Defects in any one of the many steps in collagen
fiber synthesis can result in a genetic disease
involving an inability of collagen to form fibers
properly and, thus, provide tissues with the needed
tensile strength normally provided by collagen.
- More than 1,000 mutations have been identified
in 22 genes coding for 12 of the collagen types.
28. 1. Ehlers-Danlos syndrome (EDS):
- Heterogeneous group of generalized connective
tissue disorders, result from inheritable defects in
the metabolism of fibrillar collagen molecules.
- EDS can result from a deficiency of collagen-
processing enzymes (for example, lysyl hydroxylase
or procollagen peptidase), or from mutations in the
amino acid sequences of collagen types I, III, or V.
- The most clinically important mutations found in
the gene for type III collagen.
- Collagen containing mutant chains is not secreted,
and is either degraded or accumulated to high levels
in intracellular compartments. Because collagen type
III is an important component of the arteries,
potentially lethal vascular problems occur.
29. 2. Osteogenesis imperfecta (OI):
- Known as brittle bone syndrome, also a
heterogeneous group of inherited disorders
distinguished by bones that easily bend and fracture.
- Retarded wound healing and a rotated and twisted
spine leading to a “humped-back” (kyphotic)
appearance are common features of the disease.
- Type I OI called osteogenesis imperfecta tarda,
consequence of decreased production of α1 and α2
chains.
- Presents in early infancy with fractures secondary to
minor trauma, and may be suspected if prenatal
ultrasound detects bowing or fractures of long bones.
30. - Type II OI, called osteogenesis imperfecta congenita,
most severe. Patients die of pulmonary hypoplasia in
utero or during the neonatal period
- Most patients with severe OI have
mutations in the gene for either the
pro-α1 or pro-α2 chains of type I
collagen.
- The most common mutations cause
the replacement of glycine residues
(in –Gly–X–Y–) by amino acids with
bulky side chains. T
- The resultant structurally abnormal
pro-α chains prevent the formation
of the required triple-helical
conformation.