PROTEIN Flashcards
Synthesized in the liver and secreted by the hepatocyte into the circulation
Proteins
The linear sequence of the amino acid
Determines the identity of protein, molecular structure, function binding capacity and recognition ability
Primary Structure
Refers to specific confirmations:
alpha helix
beta pleated sheets
bend form
Secondary structure
Actual 3-dimensional configuration
Folding pattern of the protein
Resposible for many of the physical and chemical properties of the proteins
Maintained by electrovalent linkages, hydrogen bonds, disulfide bridges, Van der waals forces and hydrophobic interactions
Tertiary Structures
Association of 2 or more polypeptide chains to form a functional protein molecule
Quaternary structure
What protein has no quaternary structure
Consists of only a single polypeptide chain
Albumin
Contain peptide chains which on hydrolysis yield only amino acids
May be Fibrous or Globular in shape
Simple proteins
Examples of Fibrous in shape
Fibrinogen
Troponin
Collagen
Example of Globular in shape
Hemoglobin
Plasma proteins
Enzymes
Peptide hormones
Composed of a protein and a non protein moiety (prosthetic group)
Conjugated proteins
- Ferritin
- Ceruloplasmin
- Hemoglobin
- Flavoproteins
Metalloproteins
VLDL
HDL
LDL
Chylomicrons
Lipoproteins
Haptoglobin
A1-Antitrypsin
Glycoprotein
Mucin
Higher CHO content than CHON
Mucoproteins
Chromatin
Nucleoproteins
Balance between anabolism (synthesis) and catabolism
Nitrogne balance
When protein catabolism exceeds anabolism
Excessive tissue destruction such as burns, wasting disease, high fever and starvation
Negative Nitrogen Balance
When anabolism is greater than catabolism
Ex: pregnancy, growth and repair processes
Positive Nitrogen balance
Migrates ahead of albumin
Rich in tryptophan and contains 0.5% carbohydrate
Prealbumin
Prealbumin is a transport protein for:
T4
Retinol (Vitamin A)
Prealbumin is used as a landmark to confirm that the specimen is really what
CSF
Other name of Prealbumin
Transthyretin
Reference Value of Prealbumin
18-45 mg/dL
Prtein present in highest concentration in plasma
Albumin
General transport protein
Maintains osmotic pressure
Indicator of nutritional status
Albumin
Albumin is a sensitive and highly prognostic marker in cases of what?
Cystic Fibrosis
Lowest plasma albumin levels are seen in?
Active Nephrotic Syndrome
Albumin is a ____ Acute Phase Reactant
NEGATIVE
Decreases in acute inflammatory processes
Reference Value of Albumin
3.5-5.0 mg/dL
An APR; Glycoprotein
Neutralizes trypsin-like enzymes
Released from WBCs to combat infection but can also destroy Alveoli and lead to emphysema
Comprises 90% of A1-globulin band
A1-Antitrypsin (AAT)
Synthesized initially by the fetal yolk sac and then by the fetal parenchymal cells of the liver
A1-Fetoprotein
AFP
AFP is the most abundant protein in ___
Fetal Serum
AFP peaks int he fetus at ___ weeks of gestation
13
AFP is increased in the presence of ___
TWINS
Used as a screening test for any fetal conditions such as:
Neural tube defects
Down Syndrome
Maternal serum AFP
Decreased AFP is seen in:
Down Syndrome
Trisomy 18 (Edwards Syndrome)
Has the greatest affinity for progesterone and binds quinidine
Useful diagnsotic tool in neonates with bacterial infections
A1-Acid Glycoprotein
Orosomucoid
Serine Proteinase with cathepsin G
APR
Binds and inactivates Prostate-Specific Antigen
A1-Antichymotrypsin
A1-Antichymotrypsin is associated with the pathogenesis of what disease
Alzheimer’s Disease