Epidermolysis Bullosa (EB) Flashcards
(47 cards)
What causes Epidermolysis Bullosa (EB)?
Mutations in genes responsible for skin adhesion proteins like keratin and collagen, weakening the connections between skin layers.
How is EB inherited?
It can be inherited in a dominant or recessive pattern depending on the specific gene involved.
Characteristics of fibrous proteins
- Perform structured functions
- Don’t have tertiary structure
- Insoluble in water
- Repetitive sequence of amino acids
Characteristics of Globular protein?
- Have tertiary structure
- Dissolve in water
- Perform metabolic functions
Examples of fibrous proteins
Keratin & Collagen
What layers of skin and fibrous proteins are effected during each severity of EB?
Epidermis - Keratin
Basement layer - Glycoprotein
Dermis - Collagen
How do fibrosis & globular proteins such as Keratin and Collagen and glycoproteins maintain layers of skin?
- Fibrous proteins strengthen cell-to-cell connections providing a framework for many other tissues.
- Glycoproteins maintain the basement membrane: bind to cell surface receptors causing cells to adhere to each other.
List the four levels of protein structure.
- Primary (linear sequence of amino acids)
- Secondary (α-helices, β pleated sheets)
- Tertiary (3D folding of the polypeptide chain)
- Quaternary (more than one polypeptide chain bonded)
List the four levels of protein structure bonds?
- Primary - Peptide bonds
- Secondary - Hydrogen bonds
- Tertiary - hydrogen bonds, ionic bonds, disulfide bonds
- Quaternary - hydrogen bonds, ionic bonds, disulfide bonds
(Both 3 + 4 bond at the R groups)
What is the molecular formula for a protein?
. R
l
NH2 — C —- COOH
l
H
How does protein structure relate to function?
Structure determines bonding and folding, which controls what a proteins function is in the body.
Name the four main types of EB.
- EB Simplex
- JEB
- DEB
- Kindler Syndrome
Where does blistering occur in EB Simplex?
In the epidermis (outer skin layer).
Where does blistering occur in JEB?
In the basement membrane
Where does blistering occur in Dystrophic EB?
In the dermis (deeper skin layer).
Where does blistering occur in Kindler Syndrome?
In multiple layers of the skin.
What is amniocentesis?
A prenatal test where amniotic fluid is sampled to test for genetic conditions.
What is chorionic villus sampling (CVS)?
A prenatal test using placental tissue to detect genetic mutations.
What are the 3 main layers of skin?
- Epidermis
- Dermis
- Subcutaneous fat layer
What is PCR (polymerase chain reaction) used for in EB diagnosis?
To amplify DNA creating many copies of genes and detect specific mutations in EB-related genes.
How does gel electrophoresis help identify EB mutations?
It separates DNA fragments by size , helping identify abnormal patterns linked to mutations. (This is done by moving them through a gel under an electric field)
What is DNA sequencing used for in EB diagnosis?
To determine the exact order of DNA nucleotide bases and identify gene mutations.
What are genes?
Genes are short sections of DNA that carry the blueprints for making proteins
What is point mutation and its 3 types explained?
A point mutation is a change in a single nucleotide base in the DNA sequence.
- Silent mutation: no change in the protein.
- Nonsense mutation: changes a codon to a stop codon, ending the protein early.
- Missense mutation: changes one amino acid in the protein.
