Proteins, Protein Structure, Classification of Proteins (TOPIC 2 PROTEINS) Flashcards
Composition of Proteins
Carbon
Hydrogen
Oxygen
Nitrogen
Majority of proteins are synthesized from the?
liver and some in plasma cells (immunoglobulins).
The most abundant and important macromolecules in the body.
Proteins
can acts as acids or bases depending on the pH (Zwitterion).
Amphoteric
Negatively (-) charge at alkaline pH.
Amino Group
Positively (+) charge at acidic pH.
Carboxylic Group
Transport Proteins
Albumin
Hemoglobin
Transferrin
Ceruroplasmin
pressure exerted by proteins in extracellular fluid. Decrease oncotic results to edema.
Oncotic pressure regulator (albumin)
Proteins from the food are breakdown into amino acids via
Hydrolysis
Protein catabolism (breakdown) is increased by ?
Glucocorticoids therapy and thyroid hormones
Protein anabolism (synthesis) is increased by
androgens, growth hormones and insulin.
Proteins primarily synthesized in the liver.
Alpha, beta globulins, fibrinogen and albumin
Immunoglobulins (antibodies) are synthesized in the
RTE system specifically the plasma cells.
REGULATION: Protein level is regulated by ____, ____ of _____ and _____
diet, rate of metabolism and hormones.
EXCRETION: Reabsorbed in the kidneys (normal: < _____mg/__H) anabolic (deamination) products are excreted in the urine such as ammonia and urea
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Proteins Structures
Primary
Secondary
Tertiary
Quaternary
Protein structure that refers to the sequence of amino acid in peptide or protein.
Primary structure
Protein structure that refers to
Local folding of the polypeptide chain into helixes and sheets.
Secondary structure
Types of Secondary protein structure
Alpha helix
Beta sheet
Beta turn
3 dimensional folding pattern of protein due to interaction of side chains
Tertiary structure
Unfolding of this pattern is called
DENATURATION.
Consist of 2 or more polypeptide chain or sub units forming a larger unit.
Example: hemoglobin (4 subunits)
Quaternary structure
Consists only of amino acids
Simple Protein
What are the Simple Proteins
Albumin
Histones
Globulin
Globin
Protamine
SImple proteein combined with a non protein components (prosthetic group)
Conjugated protein
What are the Conjugated Proteins
Lipoproteins- HDL, LDL, VLDL
Chromoproteins- hemoglobin, myoglobin
Glycoproteins- mucin, hormones.
Metalloproteins- Ferratin, ceruloplasmin.
Nucleoproteins -DNA
Long and narrow consist of repetitive amino acids sequence.
For structural purposes
Example:
Collagen, fibrin, keratin, actin.
Fibrinous
Spherical consist of different amino acid sequence.
For functional purposes
Example:
Enzymes, hemoglobin and hormones.
Globular/globin
Classification of proteins based on shape
Fibrinous
Globular/globin
Classification of proteins based on the solubility
soluble in water and concentrated salt solution.
Albumin
Classification of proteins based on the solubility
insoluble in water and concentrated salt solution but soluble in weak salt solution.
Globulin
Classification of proteins based on the solubility
insoluble in most reagents
Ex. Collagen, elastin, keratin
Albuminoids
is used for diagnosing Multiple myeloma and other plasma protein deficiency.
protein electrophoresis
Other basis of classification
based on molecular size and shape
ULTRACENTRIFUGATION
Other basis of classification
based on differences in size, shape and charge of protein molecules
CHROMATOGRAPHY
Other basis of classification
based on differences on molecular volume
GEL FRACTIONATION/MOLECULAR SIEVE
