intro and discussion Flashcards
(25 cards)
how to calculate a set of standards
C1V1=C2V2 which can be rearranged to V1= C2 x V2/ C1
how to calculate for dilutions
Volume of stock= total volume/ dilution factor
Volume of diluent = total volume – volume of stock
how to calculate to find unknown concentration
Concentration of unknown
= absorbance of unknown/ absorbance of standard x standard concentration
what are proteins
Proteins are large, complex molecules composed of one or more chains of amino acids joined by peptide bonds, they play a crucial role in various cellular processes including DNA replication, catalysis of metabolic reactions and structural support.
what test is done on proteins and why
Proteins are substances which contain two -CO-NH- groups (peptide bonds) joined together directly or through a single carbon or nitrogen atom which give a purple colour with alkaline copper solutions and therefore undergo Biuret reaction, and the colour produced at 540nm is proportional to protein concentration
what reactant is used with albumin and why
Albumin at pH 4.2 acts as a cation to bind anionic dyes, in these conditions albumin binds to bromocresol-green (BCG) and the absorbance of albumin-dye complex is determined spectrophotometrically at 628nm.
what is the biochemical synthesis of albumin
Liver hepatocytes are exclusive site of albumin synthesis, a continuous process regulated by nutritional status, hormone signals and plasma oncotic pressure. The synthesis process beings with transcription of the albumin gene (located on chromosome 4) to mRNA in the nucleus. mRNA is translated into a preproalbumin peptide in the endoplasmic reticulum then modified (cleaved) into proalbumin then to albumin in the Golgi apparatus, finally albumin is secreted into the plasma where it is the most abundant protein in plasma (3.5-5.0g/dL). The rate of albumin synthesis is about 10-15g a day.
albumin function
albumin helps prevent fluid leaking out of blood vessels (maintains oncotic pressure), helps vitamins, enzymes and hormones circulate throughout your body
globulin function
globulins play an important role in the immune system
what are total protein and albumin used to diagnose
kidney disease, liver disease and malnutrition.
what does high albumin suggest
High albumin levels (hyperalbuminemia) are quite rare and not directly related to liver function as the liver doesn’t overproduce albumin, its normally related to fluid balance specifically dehydration or haemoconcentration
what does low albumin suggest
Low albumin levels (hypoalbuminemia) indicate an underlying chronic or systemic condition. Chronic liver conditions such as cirrhosis and hepatitis have decreased synthesis due to damaged hepatocytes, malnutrition due to inadequate protein intake and malabsorption (Crohn’s and celiac disease). Kidney disease such as nephrotic syndrome leads to albumin loss in urine. Albumin levels also decrease in response to infection, sepsis or trauma as albumin is a negative acute-phase reactant.
what does high total protein suggest
High total protein (hyperproteinaemia) is less common but still clinically significant often suggesting chronic inflammation, plasma cell disorders or dehydration
what does low total protein suggest
Low total protein levels in the blood (hypoproteinaemia) is the sum of albumin and globulins (including antibodies) so low levels often reflect issues with liver function such as liver disease, nutrition (malnutrition and malabsorption), immune status or protein loss or reduced protein synthesis
what are some clinical implications to low albumin and total protein
edema, delayed healing and increased infection risk.
what is bilurubin
Bilirubin is a yellowish pigment, a byproduct of the natural breakdown of red blood cells, found in bile and produced in the liver to aid in digestion
what does high bilirubin say
Elevated levels of bilirubin (total and conjugated) suggest hepatocellular damage or bile duct obstruction, it is used to differentiate between haemolytic jaundice (unconjugated bilirubin) and obstructive or hepatic jaundice (conjugated bilirubin).
what does prolonged prothrombin time say
Prolonged prothrombin time reflects decreased synthesis of clotting factors indicating liver dysfunction
what are transaminases
enzymes that catalyse the transfer of amino groups between molecules
what are the 2 main transaminases
asparate aminotransferase (AST) and alanine aminotransferase (ALT)
what do transaminases levels suggest
. Aspartate aminotransferase (AST) is liver specific and becomes elevated in acute liver injury and alanine aminotransferase (ALT) is also present in the muscle and the heart. If ALT > AST it suggests viral hepatitis and if AST> ALT it suggests alcoholic liver disease.
what are cholestatic enzymes
liver enzymes that increase when bile flow is impaired (cholestasis).
what are the 2 main cholestatic enzymes
alkaline phosphatase (ALP)
glutamyl transferase (GGT)
what do cholestatic enzymes show
Alkaline phosphatase (ALP) is elevated in bile duct obstruction and y-Glutamyl transferase (GGT) confirms the hepatic source of elevated ALP.
