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Showing posts with label enzymes. Show all posts
Showing posts with label enzymes. Show all posts

Wednesday, September 26

Enzymes as catalysts

Experiment # 10: How enzymes work

Materials Needed:
* Two jars with lids
* diluted hydrochloric acid
* ground beef (raw)
* iodine
* crackers
* cornstarch
* dextrostik strips (to test for sugar)

Procedure:
1) In one jar, place diluted hydrochloric acid (muriatic acid) and a piece of ground beef.
2) In the second jar, put a piece of ground beef. Leave for 24 hours.
3) After 24-hours, compare the beef on both jars.
4) What is your explanation?

5) Chew a cracker for 30 seconds without swallowing.
6) Describe the change in flavor and explain the result.

7) Collect several teaspoons of saliva in a glass (saliva contains enzyme amylase).
8) Mix a paste of 1T. cornstarch and 1 c. of water.
9) Heat to boiling and cook for 10 min. Stir to prevent burning.
10) Put  1T. of the thick paste into each of  2 jars.
11) Add 1T. of saliva to one jar and 1T. of water to the other. Place in warm place for 1 hour.
12) Examine visually.
       * Describe any difference in appearance.
13) Perform the carbohydrate test on each for sugar.
      * Describe the result.
14) Perform  the carbohydrate test for starch on each.
      * Describe the result.
Findings

Photo above:
Clockwise: Jars of meat after 24 hrs; jars of meat before putting muriatic acid on one jar; water jar tested for starch; water jar tested for sugar; saliva jar tested for starch; saliva jar tested for sugar.

Findings:
* Beef with the acid rapidly decomposed.
* Jar with saliva and corstarch appears clearer than the jar with water. It has sugar but does not show starch.
*Jar with water and cornstarch has no sugar but has starch.
* That enzyme amylase in saliva turns starch in food to sugar while being chewed. That is why the crackers tasted sweeter.
* Digestion breaks down proteins into its component amino acids.

Tuesday, August 7

We are almost ready. . . for Science

Made that trip to Sta. Cruz, Manila last week to scour for our Science experiment materials.

Our stash is almost complete for Unit 2 and we are ready to go! Gia and I can't wait to start with our Science experiments and activities. =)

The list of materials ( excluding common household items) for AOP Lifepac Science for Grade 10 consists of:
  • Alligator clip leads, 2/pk
  • Alpha Omega Biology Slide Set
    Ascaris mitosis, onion root tip, Diatoms, frog ovary, frog sperm, human blood smear, human bone, kidney section, muscle types section, motor neuron smear, Spirogyra, and Ulva microscope slides
  • Battery, 6 volt, alkaline
  • Beaker, glass, 250 ml
  • Biuret reagent, 30 ml
  • Calcium hydroxide, 30 g (lime)
  • Chalk (calcium carbonate), 12/pack
  • Cups & lids, 8 oz plastic, 3/pack
  • Electrolysis electrodes (2)
  • Filter paper, 10/pkg
  • Forceps, stainless steel
  • Funnel, plastic, 65 mm dia.
  • Glucose test strips, 50 pack
  • Graduated cylinder, plastic, 10 ml
  • Hydrochloric acid, 30 ml
  • Iodine solution (Lugol's) 30ml
  • Lab apron, economy
  • Litmus paper, blue, 100 strips
  • Litmus paper, red, 100 strips
  • Magnifier, tripod, 10X
  • Methylene blue, 1%, 15 ml
  • Osmosis Set
  • P.T.C. test paper, 100/vial
  • Petri dish, plastic, 2/pk
  • Phenolphthalein solution, 15ml
  • Pipet (medicine dropper)
  • Potassium permanganate, 30 g
  • Probe & seeker, chrome, 6"
  • Protozoa Hatchery Kit
  • Razor blade, single edge
  • Safety gloves, size 8-8½ med.
  • Safety goggles, full-size
  • Sand, coarse, 1 lb.
  • Scissors, dissecting, 4½"
  • Screen, 20 mesh, steel, 4x4"
  • Seeds, grass, 6 g pack
  • Seeds, lima bean, 15 g pack
  • Seeds, marigold, 300 mg pack
  • Seeds, radish, 4 g pack
  • Basic microscope slide set: 12 plain slides, 2 concave slides, coverslips, and storage box
  • Sodium sulfate, 30 g
  • Stirring rod, glass, 6"
  • Teasing needle, straight
  • Test tube rack, 6 holes
  • Test tubes, small 13x100 mm
  • Test tubes, x-large 19x150 mm
  • Thermometer, Celsius, 12"
Yes! a very long list of items that. . . after the school year, we will have our own Science Laboratory! LOL!

Hopefully we will be able to complete them before the end of the school year. One Unit at a time. :)

Unit 2 (Basis of Life) will be about : 

* molecular models
* ionic and covalent bonding
* inorganic compounds experiment about solvent, thermal properties of water, acids,  bases and salts
* chemical reactions like electrolysis and using yeasts
* organic compounds like testing for starch, sugar, oil and protein in some food
* and,  properties of enzymes

So here's our stash (in photo) :





Grade 10 Unit 2 materials

stored securely (p.s. we need a bigger container soon)

Oh how this simple exercise of gathering all the materials reminds me of how I love Science back when I was in school. 

Rocking Science we should be!