Plasma Proteins Flashcards
where are polar groups found on globular proteins
On the proteins surface
Where are hydrophobic groups found in globular proteins
In the globular protein interior
Fibrous vs Globular protein solubility
Folding in globular proteins increases solubility of proteins in water
Fibrous proteins are mainly insoluble structural proteins
What structure do globular proteins have
Quaternary structure
Hemoglobin structure
- 4 polypeptide chains: two alpha, 2 beta
- Held together by non covalent interactions
- Each chain has a heme group in center that carries oxygen
- Hb molecule has 4 heme groups and carries 4 O2 molecules
Hb function
Carries O2 & CO2 to and from the lungs and tissues
What does HbA undergo
Glycosylation (addition of glucose)
Who are HbA1c levels high in
Patients with diabetes mellitus
Function of albumin
Transports hormones, fatty acids, cholestrol through the blood
Is albumin solube/insoluble
Soluble
What is albumin synthesised as
As a pre-proprotein
Low blood albumin levels caused by (6)
- Liver disease: cirrhosis most common
- Excess excretion by the kidneys: as in nephrotic syndrome
- Burns: plasma loss in absence of skin barrier
- Redistribution
- Acute disease states
- Mutation causing albuminemia (v/ rare)
High blood albumin levels caused by (3)
- Severe/chronic dehydration
- Retinol (vit A) deficiency
- High protein diets
APRs concentration changes in… (4)
- Infection
- Surgery
- Injury
- Cancer
Examples of positive APRs
- C-reactive protein
- Fibrinogen
- alpha 1 antitrypsin
Examples of negative APRs
- Albumin
- Transferrin
- Antithrombin
Globulins vs albumins
Globulins have a higher molecular weight & water solubility than albumins
What are globulin made of
Different proteins called alpha, beta and gamma types
Function of globulins
Bind with Hb to transport metals (e.g.: iron) in the blood & fight infection
What are high globulin levels caused by (10)
- Chronic inflammatory diseases (TB)
- Bone marrow disorders (multiple myeloma)
- Leukemias
- Autoimmunity (collagen diseases)
- Rheumatoid arthritis
- Liver disease
- Carcinoid syndrome
- Ulcerative colitis
- Kidney disease (nephrosis)
- Chronic infections
Low globulin levels are caused by (7)
- Hepatic dysfunction
- Celiac disease
- Inflammatory bowel disease
- Acute haemolytic anaemia
- Proteins not digested and and absorbed properly
- Hypogammaglobulinemia
- Renal disease (kidneys dont filter protein from blood and it leaks into urine)
What is transferrin
beta globulin
Fuction of transferrin
Binds free iron in serum
What causes decreased transferrin levels
- Liver disease (cirrhosis)
- Chronic infections
- Nephrosis
- Congenitalatransferrinaemia
What are immunoglobulins
Antibodies produced by B cells in response to antigen stimulation of the organism
Immunoglobulin structure
- Minimum 4 polypeptide chains
- 2 heavy chains and 2 light chains linked by disulphide bridges
- Light chains contain the constant and variable region
