Biology Lab Chapter 3

Question 0

What is a control

Answer 0

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.

Question 1

Organic molecules of cells

Answer 1

Proteins, carbohydrates (monosaccharides, disaccharides, polysaccharides, and lipids (i.e., fat)

Question 2

What is R group

Answer 2

Remainder group, that has varying sizes, shapes, and chemical activities.

Question 3

Test for Proteins

Answer 3

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.

Question 4

Biuret Test for Protein and Peptides

Answer 4

Protein Peptides
Purple Pinkish-purple

Question 5

Test for starch

Answer 5

Iodine solutions (yellowish-brown)
Turns starch to blue-black

Question 6

Test for sugars

Answer 6

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.

Question 7

Benedict’s Test for Sugars - glucose/carbohydrates

Answer 7

Green (low) to orange red (very high)

Question 8

Test for Fat

Answer 8

Brown paper or loose-leaf paper. Will leave an oily spot

Question 9

Lipids

Answer 9

Compounds that are insoluble in water and soluble in solvents, such as alcohol and ether. Typically fat.