Molecular Cell Biology Year 1 PDF

MOLECULAR CELL BIOLOGY  Biochemical Tests Part 1: Basic Principles of Laboratory Analyses ↑ The reason biochemical profiling is important is because it assesses the physiological status of an individual which can underpin a huge...

MOLECULAR CELL BIOLOGY  Biochemical Tests Part 1: Basic Principles of Laboratory Analyses ↑ The reason biochemical profiling is important is because it assesses the physiological status of an individual which can underpin a huge amount of diagnosis’s. It’s tailored to separating patients based on specific characteristics that allows for improving in treatment plan. Things to consider when thinking about tests: 1. Picking the most efficient tests 2. Making sure each test has a valid justification 3. Making sure the test is in the patients best interest Ordering unnecessary tests is costly How are biomolecules measured in the laboratory? Each molecule absorbs light energy differently so when a light source passes through a solution the amount of light absorbed = number of molecules in that solutions - Absorption is measured in optical density (OD) units ↑ Sometimes biomolecules are measured in colour known as colorimetric assays ↑ EXAMPLE: GLUCOSE 1. Glucose is converted by Glucose Oxidase to make D-Gluconic Acid 2. While that’s happening oxygen is converted to hydrogen peroxide by an enzyme called oxidase enzyme 3. Hydrogen peroxide will react with Horse Radish Peroxidase (HRP) that creates a colour (wavelength absorption 540-570nm) 4. That is how much glucose molecules are present How to find Samples of unknown concentrations 1. Plot five known samples 2. Use OD value and trace along graph horizontally to the line of best of fit 3. Read glucose value Part. 2: Screening VS Specific Function Tests - Screening test: data reflects general conditions of individual and takes a short amount of time - Specific function test: done after screening test and gives more detail on whether a specific system has damage Types of samples include: blood and urine, saliva, and sweat EXAMPLES: Urea and electrolytes Most requested type of test and serum urea level indicates the effectiveness of - renal function. Electrolytes also indicate renal function and general condition due to electrolyte imbalance. Plasma VS Serum Plasma is the liquid that has not been clotted (anticoagulanted) while serum is - blood that has been clotted (coagulated) (prevents excessive bleeding) Centrifugation is the process of separating light and heavy fluid. Plasma is usually - used for more specific test Sampling Sites 1. Venous- it is more commonly used for analyzing blood cell contents. For example checks for glycosylated haemoglobin, white blood cell (leukocytosis and leukopenia), red blood cell count (erythrocytosis and erythropenia) 2. Arterial- measure for arterial partial pressure of oxygen, carbon dioxide and pH. Not commonly used as it carries an inherent risk due to high pressure. Indicates hypoxaemia (low oxygen tension in circulation while hypoxia is low in tissues) 3. Capillary- used for patients like infants, fragile veins, and severe burns JOIN THE DARKSIDE Part 3: U & Es, Reference Ranges, and Myocardial Infarction Urea is the breakdown product of protein/amino acid metabolism from the Blood. Amino acids are processed to ammonia in the liver and combined with CO2 to · produce urea. Urea travels through the blood to the kidney and is excreted. How to measure blood urea? Take sample of clotted venous blood and extract the serum after centrifugation. 1. Urease converts urea to ammonium 2. Ammonium coupled with 2-Oxoglutarate (OG) 3. Glutamate dehydrogenase converts ammonium and OG to glutamate 4. Simultaneously NADH is converted to NAD 5. NADH is measured High urea can indicate kidney function alteration or dehydration Low urea can be due to chronic liver disease, starvation, or pregnancy related Urea and Electrolytes They are measured by ion selective electrodes (ISE). This is 2 electrodes (referent electrode & sample/ indicator electrode). The reference electrode allows all ion influx into electrode while the other one allows only certain ions. Due to this there is a potential different between the 2 poles and the current reflects particular ion in a sample. Electrolyte imbalance be a result of: chronic renal malfunction, dehydration, liver failure Why are reference ranges important? It indicates the range where people fall into the healthy value but factors like biological sex, ethnicity, and socioeconomic status affect the ranges Each test can measure a variety of things like the liver function test and therefore multiple reference ranges Myocardial Infarction & Troponin Troponin is a protein that’s found in heart muscle cells and we analyze this protein to determine heart damage. Abnormal levels indicate ischaemic cardiac damage. TnC, TnI, TnT are subunits of the Troponin complex and detection of the last 2 indicates cardiac muscle damage Detection of Troponin To detect it 2 antibodies are used and they target different parts of the cTnI protein. The first antibody is attached to magnetic beads and the second one attaches to an enzyme called alkaline phosphatase (ALP). Both of these bind to different parts of the cTnI molecule. When exposed to patient blood sample any cTnI in the blood binds to these 2 antibodies. After the cTnI molecules are in the middle a chemical is added (Lumi-Phos *350) and it reacts with the ALP enzyme producing a little bit of light. This light is measured by a luminometer and the amount of light produced relates to the amount of cTnI in the sample. Higher levels could mean health problem Part 4: Patient Case Study Diabetic ketoacidosis can lead to increased metabolism of fats. This breakdown produces small organic acids called ketone bodies that act as an alternative energy source but an accumulation of these can cause acidosis JOIN THE DARKSIDE