Biology Lab Chapter 3 Flashcards
What is a control
Positive control - goes through all the steps of the experiment and does contain the substance being tested.
Negative control - goes through all the steps of the experiment except it does not contain the substance being tested. Therefore, negative results are expected.
Organic molecules of cells
Proteins, carbohydrates (monosaccharides, disaccharides, polysaccharides, and lipids (i.e., fat)
What is R group
Remainder group, that has varying sizes, shapes, and chemical activities.
Test for Proteins
Burnet reagent (blue color) contains a strong solution of sodium or potassium hydroxide (NaOH or KOH) and a small amount of dilute copper sulfate (CuSO4) solution.
Biuret Test for Protein and Peptides
Protein Peptides
Purple Pinkish-purple
Test for starch
Iodine solutions (yellowish-brown) Turns starch to blue-black
Test for sugars
Benedict’s reagent (blue). Careful it is highly corrosive. If it spills on skin wash the area with mild soap and water. Let instructor know and follow her directions.
Benedict’s Test for Sugars - glucose/carbohydrates
Green (low) to orange red (very high)
Test for Fat
Brown paper or loose-leaf paper. Will leave an oily spot
Lipids
Compounds that are insoluble in water and soluble in solvents, such as alcohol and ether. Typically fat.