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100
What is meant by the term “metabolism”?
A sequence of enzyme catalysed chemical reactions in the cell – both anabolic and catabolic
100
Anabolic and catabolic pathways are different. Briefly explain two of the differences between an anabolic pathway and a catabolic pathway.
Anabolic – involved in assembly of complex organic molecules. Making molecules, requires electrons (reductive), requires energy, pathway usually divergent. Catabolic – degradation of complex substances resulting in generation of energy. Breaks down molecules, donates electrons, yields energy, pathway usually convergent.
100
What is an enzyme?
Catalysts important in regulating the chemistry of cells and organisms. Necessary to make many essential biochemical reactions proceed at a useful rate under physiological conditions.
100
What is an enzyme “active site”?
Part of enzyme involved in the catalytic reaction occurs
100
When referring to an enzymatic reaction, what is meant by the term “substrate”?
The reactant in an enzyme catalysed reaction, substance acted upon by the enzyme
200
When referring to an enzymatic reaction, what is meant by the term “product”?
End of a chemical reaction where a product is produced
200
List and briefly explain four (4) variables that can effect enzyme activity.
Temperature – optimal temp where catalytic activity is optimum, differ widely in temp sensitivity PH – optimal pH, vary widely in pH sensitivity Concentration of substrate – more concentration = higher reaction rate Concentration of enzyme – reaction rate has a linear relationship with enzyme activity
200
A laboratory assay uses an enzymatic reaction as part of the assay procedure. Explain why the incorrect incubation time for the laboratory assay may affect the results of the assay.
The longer an enzyme is incubated with its substrate, the greater the amount of product that will be formed. However, the rate of formation of product is not a simple linear function of the time of incubation. Denaturation will happen, therefore a loss of catalytic activity with increased incubation time. Some enzymes may be unstable and lose significant amount of activity. Much of substrate could be used during incubation, and formation of the product may decrease.
200
List 4 different types of biological specimens that may be used in a Biomedical Science or Pathology laboratory.
Blood, Urine, Faeces, Solid Tissue
200
Name the cellular components of blood.
RBC, WBC, platelets
300
Name 3 components of blood required for clotting.
Ca2+, Platelets, Clotting proteins
300
Is there a difference between serum and plasma? Explain your answer.
Yes. Plasma is the liquid portion of whole blood. Serum = remaining liquid portion of clotted blood. Serum is essentially the same as plasma minus the clotting proteins
300
What is an anticoagulant?
Substance which inhibits the coagulation of blood
300
List one anticoagulant and explain its mode of action.
Heparin – inhibits clotting proteins e.g. thrombin
300
Why are different anticoagulants used when collecting blood?
Different coagulants can do different things e.g. EDTA is used in Haem as it complexes divalent cations, Oxalate is used in some tests as it chelates calcium which is irreversible
400
Why is correct identification of a patient sample important?
For underlying issues such as posture, immobilisation, exercise, circadian variation, underlying medical condition, food/drugs/stimulants
400
List 2 reasons that a patient sample may be unsuitable for a laboratory assay, necessitating the recollection of a sample.
Incorrect anticoagulant used,
400
Haemophilia is a disease studied in a Coagulation laboratory. What is Haemophilia?
Haemophilia is incurable and without proper treatment, can be life threatening. It is a blood clotting disorder where there is not enough clotting factor VIII (8) or IX (9) in the blood. A clotting factor is a protein in the blood that helps control bleeding.
400
Why might a protein need to be separated from a mixture of other proteins?
Need to isolate one specific protein to analyse. It is vital for the characterization of the function, structure and interactions of the protein of interest.
400
What types of molecules can be separated from a mixture using Chromatography?
organic
500
List three Chromatography principles that can be used to separate a molecule of interest from a mixture. For each of the principles that you listed above, what property of the molecule of interest is being utilised (eg size, charge, etc)
Ion Exchange - charge Gel Filtration - size Affinity Column -
500
What factors may affect the reliability of a laboratory test result?
Combination of accuracy and precision
500
Explain the term Accuracy when referring to laboratory results. Use a hypothetical example in your explanation.
Accuracy is how close you get to the target
500
Explain the term Precision when referring to laboratory results. Use a hypothetical example in your explanation.
Precision is how many times you can get the same result (not necessarily the closest to the target)