Lab Exam Flashcards
What regulates the concentration of sugars (glucose) in the blood?
the antagonistic controls of insulin and glucagon
Which peptide hormone is released when glucose levels are high?
insulin
What releases insulin into the bloodstream?
the pancreas
What peptide hormone is released when glucose levels are low?
glucagon
What releases glucagon into the bloodstream?
the pancreas
what is the novel technique used in the Bo et al., (2013), study?
a technique that detects glucose concentrations using a DNAzyme (a synthetic enzyme)
What is DNAzyme?
a synthetic enzyme that detects glucose
made of a G-rich oligonucleotide and hemin
acts like a peroxidase in the presence of glucose oxidase and glucose to oxidase ADHP into resorufin
What is DNAzyme made of?
a G-rich oligonucleotide and hemin
What is the function of DNAzyme?
to oxidize ADHP into resorufin in the presence of glucose oxidase and glucose
acts like a peroxidase
What enzyme does DNAzyme imitate?
peroxidase
What is ADHP?
10-acetyl-3,7-dihydroxyphenoazine
What colour is ADHP before it’s oxidized?
colourless
What colour is ADHP when it’s oxidized?
red
How is the concentration of glucose determined?
spectrophotometry at 570 nm used to detect resorufin which a standard curve can be made from to determine glucose concentration in the sample
Who won the Nobel Prize in 1923? For what?
Frederick Banting won for discovery of insulin
What type of feedback loop is regulation of blood glucose?
negative feedback
explain how blood glucose levels are regulated by a negative feedback loop
when blood glucose is high:
- B cells of pancreas are stimulated to secrete insulin into the bloodstream
- insulin targets organs to increase their glucose uptake
= reduces glucose levels in blood (brings parameter back to set point)
AND
- a cells of pancreas are inhibited to prevent the secretion of glucagon into the bloodstream
= reduces glucose levels in blood (brings parameter back to set point)
Which pancreatic cells secrete insulin?
beta cells
Which pancreatic cells produce glucagon?
alpha cells
Where are the pancreatic cells which secrete insulin and glucagon located?
in the Islets of Langerhans of the pancreas
Describe how blood glucose levels are antagonistically controlled
insulin is secreted by pancreatic B cells to lower glucose levels
glucagon is secreted by pancreatic a cells to raise glucose levels
What was the purpose of the glucose metabolism experiment?
- to observe the behavioural differences (gill cover, movement) between control fish and fish exposed to insulin
- to use a DNAzyme to detect the concentration of glucose in the fish’s urine and blood samples when exposed to glucose or insulin, or neither (control)
What organism was used in the glucose metabolism experiment?
diamond tetras, Moenkhausia pittieri
What were the 3 parts of the glucose metabolism experiment?
A (lab coordinator): prepare hemin-G-quadruplexes DNAzymes solution
B: Observe fish behaviour (control v. insulin)
C: Measure glucose from tank water and blood samples (control v. glucose exposed v. insulin exposed)