Proteins Flashcards
First rank of importance
Proteis
Amphoteric: positive and negative charges
Proteins
Effective blood buffers
Proteins
Synthesized by the liver except immunoglobulins (plasma cells)
Proteins
Provide 12-20% of total daily body energy requirement
Proteins
Composed of 50-70% of the cell’s dry weight
Proteins
Amino acid sequence
Primary structure
Det. the identity of protein, molecular structure, function binding capacity, recognition ability
Primary structure
Winding of polypeptide chain
Secondary structure
Specific 3-D conformations: alpha-helix, beta-pleated sheath, bend form
Secondary structure
Actual 3-D configuration
Tertiary structure
Folding pattern
Tertiary structure
Physical and chemical properties of proteins
Tertiary structure
Association of 2 or more polypeptide chains > protein
Quarternary structure
No quarternary structure
Albumin
Glucogenic amino acids:
Alanine (pyruvate)
Arginine (alpha-ketoglutarate)
Aspartate (oxaloacetate)
Degraded to acetyl-CoA
Ketogenic amino acids
Ketogenic amino acids
Leucine
Lysine
Hydrolysis > Amino acids
Simple proteins
Simple proteins Fibrous:
fibrinogen, troponins, collagen
Simple proteins Globular:
hemoglobin, plasma proteins, enzymes, peptide hormones
Protein (apoprotein) + nonprotein moiety (prosthetic group)
Conjugated proteins
Metalloproteins:
ferritin, ceruloplasmin, hemoglobin, flavoproteins
Lipoproteins:
VLDL, HDL, LDL, CM
Glycoproteins:
haptoglobin, alpha1-antitrypsin (10-40% CHO)
Mucoproteins or proteoglycans:
Mucin (CHO > CHON)
Nucleoproteins:
Chromatin (combined w/ nucleic acids)
Balance bet. anabolism and catabolism
Nitrogen balance
Catabolism > anabolism
Negative nitrogen balance
Excessive tissue destruction
Negative nitrogen balance
Anabolism > catabolism
Positive nitrogen balance
Growth and repair processes
Positive nitrogen balance
Transports thyroxine and retinol (Vit. A)
Prealbumin (Transthyretin)
Landmark to confirm that the specimen is really CSF
Prealbumin (Transthyretin)
Maintains osmotic pressure
Albumin
Negative acute phase reactant
Albumin
Acute phase reactant
Alpha1-antitrypsin
Major inhibitor of protease activity
Alpha1-antitrypsin
90% of alpha1-globulin band
Alpha1-antitrypsin
Gestational marker
Alpha1-fetoprotein
Alpha1-fetoprotein Tumor marker:
hepatic and gonodal cancers
Screening test for fetal conditions (Spx: maternal serum)
Alpha1-fetoprotein