Remember...diabetes is a disease that occurs when blood glucose (i.e., blood sugar) is elevated because the body isn't making enough insulin or doesn’t use insulin well. The glucose then builds up in the blood, and doesn’t reach the cells where it is needed as an energy source. Over time, having too much blood glucose causes the serious and chronic health problems associated with diabetes.
Because the blood glucose levels in diabetics are not well regulated, their diet becomes much more important. Primarily, diabetics have to be concerned with the frequency and types of carbohydrates they consume. Carbohydrates can be identified by their glycemic index (GI), which is a measure of how quickly the carbohydrate is broken down into its component parts to be used by the body.
However, keep in mind, diabetics don't just manage their diets based on the GI. They must also select foods that maintain their cholesterol and triglycerides levels, blood pressure, and weight management.
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Lab 3 will proceed in three parts:
1) The pipette challenge: You will learn the basics of measurement, including how to correctly transfer liquids using micropipettes. ![]() If you've never used a micropipette before, try practicing a bit in this virtual lab setup. |
Lab 3: ProtocolIn today's lab you will learn how to use a micropipette. You will set up experiments to try and predict the glycemic index of unknown food items and, if time allows, you can continue analysis of the diabetes data.
Exercise I. Pipette Challenge Exercise II. Predict the Glycemic Index Exercise III. Continue Analysis |
At the beginning of lab, your instructor will demonstrate how to properly use a micropipette.
Watch carefully and follow along.
Review the parts of a micropipette: Diagram at right.
Please keep the following in mind to increase the likelihood of both accurate and precise measurements in lab:
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Your task in Exercise II is to develop a series of tests, using chemical indicators, to predict the glycemic index (GI) score of unknown food items. If you have ANY questions about what a macromolecule is, or what the GI is, please refer to the pre-lab above.
![]() Materials: Your Tool Kit
SPECIAL NOTE: All of these tests are time-sensitive and should be read following the strict protocols in the side bar. A bright yellow/orange result on a Biuret test is common if you wait too long to read it; it is still a NEGATIVE result and is related to pH. A dark brown test result with Benedict's means it might have stayed in the water bath for too long but is a POSITIVE result. You can expect results like the ones pictured to the left. |
Procedure
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Indicator Info & Protocols |
Procedure
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If you finish early, work on your report. LAB 2 Exercise III. has all the details. |
Dr. Jacobshagen is extremely interested in clocks; not the kind hanging on the wall or on your phone, but biological clocks and circadian rhythms. She explores these internal physiological regulators, like the sleep/wake cycle, using algae as a model organism. Projects in her lab center on particular types of macromolecules called, photoreceptor proteins that are able to reset these circadian clocks. She is an accomplished researcher in the field of biochemistry and teaches our BioChem courses. She is also heavily involved with the Biochemisty Major. Reach out to her if you found Lab 3 particularity interesting or if you're still trying to decide what track you'd like to pursue in our department. |