Question: In which environment (warm, cold, or room temperature

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					Mid-Term Lab. Practical Questions
General Biology 1408

Name: ………………………… Section: Day/time……………………………..

Metric System lab.

    1. Conversions between units

   If there are 1000 meters in a kilometer
                  o How many meters are there on 0.5 km?

   If there are 1,000,000 micrometers (µm) in a meter
                  o How many meters are there in one millimeter (mm)?

   If there are 1,000,000 mg in a kilogram (kg)
                  o How many kg in 10 mg?




2. This microscope is called a compound microscope because of the fact
that ……………………………………………………………………………………..




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3. What function is performed by the following parts of the microscope
A) Condenser………………………………………….

B) Course Adjustment Knob ………………………..

C) Which objective lens would you use the oil with?? (i.e., mention the
   magnification power of the lens of your choice)


4. Why is locating an object is more difficult if you start with the higher-
power objective than with the low-power objective?




5. Match these cell structures with their functions : (Each question has
ONLY one answer)

-----   Mitochondria              -----   Nucleus_
-----   Golgi Apparatus           -----   Lysosome
-----   Cell Membrane             -----   Cytoplasm
-----   Ribosome                  -----   Flagella


A) Where glycolysis occurs                     B) where DNA is kept

C) The powerhouse of the cell                  D) where proteins are made

E) Used for motility (movement)                F) made of phospholipids

G) Contains hydrolytic enzymes                 H) Sorting and packaging of
                                               proteins




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6. Tell which building blocks are required to make each of these groups
of macromolecules. Also give an important function for each type of
macromolecule:

Macromolecules           Building Blocks                Function
Proteins
Lipids
Carbohydrates


TONICITY EXPERIMENT




7. What terms would be applied to each of the blood cells in the drawing
above? (Indicate the terms on the above drawings)

TERM: _____________________

8. The police are trying to determine if material removed from a scene of a
crime was plant or animal or a bacterial matter. What would you suggest
they should look for to determine the source?

   Plants: ___________________________

   Animal: __________________________

   Bacteria: _________________________




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9. Name the method that best describes the movement of the dye in the
above diagram?

10. Does the above method require Energy? ……….. If not, mention a
process that requires energy?

11. In which environment (solid or liquid) do you think the greatest
movement will occur? What evidence or knowledge leads to your answer
(i.e. explain an experiment you have done in the lab)?


12. If a dialysis bag filled with water is placed in a molasses solution, what
do you predict will happen to the weight of the bag over time? WHY?


13. Label the cells in the drawing below , indicating direction of
water movement and tonicity (hyper-, hypo-, isotonic)




14. What term is applied to a plant cell when it has shriveled up inside the
    wall? ……………………………




15. A. Compare the shape of the plant cells with the human cheek cells.


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   B. Are there structures present in one but not in the other? If any,
         Mention at least two structures that present in plant cells but not
         animal cells?


TEST FOR CARBOHYDRATES

           Tube          Contents           Color (post-heating)

            1         Distilled water       Blue (-ve)

            2           Potato juice        Yellow (+)

            3         Starch Solution       Blue (-ve )

            4           Onion juice         Yellow-Orange (+++)

            5       Glucose solution        Orange-Red (++++++)


Fill the blank
16. .………………… Reagent offers a simple test for the presence of simple
sugar

17. According to the data in the above table ,What purpose does the tube
containing only distilled water serve?

18. Which tastes sweeter, potatoes or onions? ……………………
   Provide scientific evidence.



TEST FOR STARCH

Lugol's iodine, also known as Lugol's solution, first made in 1829, is a
solution of iodine named after the French physician J.G.A. Lugol. Lugol's
iodine solution is often used as an antiseptic and disinfectant, a starch
indicator, to replenish iodine deficiency, to protect the thyroid gland from
radioactive materials (e.g. "fallout"), and for emergency disinfection of
drinking water

                         Distilled water


                                        5
                          Glucose solution
                          Sucrose solution
                          Onion juice
                          Potato juice

19. Name the reagent used to test for the presence of
Starch…………………….

20. What color would result if a test is positive for starch? …………

21. Which of these samples do you suspect will contain starch?
……………………

22. If a structure DOES NOT change color in the presence of lugol’s
iodine, what is your conclusion? …………………………………………….

TEST FOR PROTEINS

Biuret is a reagent that will change color (from blue to violet) when it
detects peptide bonds between amino acids of a polypeptide (or protein).
Violet is a positive test, blue is a negative test.

                         Onion juice
                         Glucose solution
                         Distilled water
                         Potato juice
                         Albumin solution


23. Which of the solutions to be tested do you believe will contain protein?
……………………………

24. Name one enzyme that breaks down a protein?
…………………………….

Assuming you have two test tubes
           TUBE 1 contains: Albumin + Water + HCl
           TUBE 2 contains: Albumin + Pepsin + HCl

25. Which of the above tubes will result in a positive reaction? (violet color)
………………………… WHY? ……………………………………………………


26. Pick out the properties of enzymes:



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A) Slow down chemical reactions       B) speed up chemical reactions
C) Are proteins                       D) are nucleic acids
E) Can be used only once              F) can be used over and over
G) Are insensitive to temperature     H) are damaged by very high
                                          temperatures
I) Are insensitive to pH              J) have pH optima


Fruits and vegetables can be kept fresh by storage at coldish
temperatures, because the cold slows down all cellular mechanisms. This
is similar to hibernation - the cells are still alive, but do not need a high
turnover of oxygen and nutrients. However, one of the banes of apples and
bananas, from a consumer point of view, is browning. The browning is
caused by a reaction between catechol and oxygen, catalyzed by the above
enzyme "catechol oxidase" resulting in benzoquinone. This compound is
brownish in color and is toxic to bacteria. When the peel is damaged,
oxygen can then react with the catechol, protecting the fruit




27. Name the enzyme that catalyses the above reaction…………………..

28. How do you know if a tested sample is positive based on the above
equation? …………………………………….


29. What is spectrophotometer? How did you apply the use of
spectrophotometers in the above experiment?



30. Name any three conditions that maximize enzymatic reaction.
A…………………………
B…………………………
C…………………………




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