Tuesday, July 20, 2010

Inorganic chemistry

               Bio-onorganic chemistry ia an interdiscipilanary area of inorganic chemistry and biology. Bio-inorganic chemistry deals with the study of the role of inorganic elements in biochemical process. Nearly thirty elements of the periodic table are found to be essential for life processes. Their deficiency leads to serious disorders. Such elements are known as essential elements. Among them twenty one elements are needed in very small amounts. They are called as trace elements or micronutrients. Example : Iron, Copper, Cobalt, Manganese, Zinc, Molybdenum, Chromium, Iodine etc.
                Metal ions of proteins and enzymes can do many specific functions in biological processes. Some metals function as cofactors for many enzymes. The role of metal ions in the biological system may be given as follows.
  1. Sodium is the major cation of the extracellular fluid.
  2. Along with chloride and bicarbonate, sodium regulates the body's acid-base balance.
  3. It maintains osmotic pressure and protects the body against excessive fluid loss.
  4. It maintain the normal water balance and distributions.
  5. It is involved in the absorption of glucose, galactose and amino acids from the small intestine.
  6. It maintains the normal neuromuscular functions.
  7. It is necessary for initiating and maintaining heart beat.
  8. It functions in the permeability of the cells.
  1. Potassium maintains intracellular osmotic pressure.
  2. It plays an important role in the regulation of acid-base balance in the cell.
  3. It regulates the water balance in the cells.
  4. It is essential for protein biosynthesis by ribosomes.
  5. The enzyme pyruvate kinase requires K + for optimal activity.
  6. Extracellular K+ influences cardiac muscle activity.
  7. Potassium is required for the transmission of nerve impulse.
  8. It influences muscle activity.
  1. Calcium along with phosphorus is essential for the formation and development of bones and teeth.
  2. Calcium ion is required in the blood coagulation process.
  3. It is essentisl for nerve impulses and muscular contraction.
  4. It regulates the permeability of membranes.
  5. It functions as second and third messenger for some hormones.
  6. The release of certain hormones from the endocrine glands is facilitated by calcium ions.
  7. The cell to cell communication mau also require calcium ions.
  8. Calcium ion act on myocardium and prolongs systole.
  9. It required for the activation of several enzymes such as succinate dehyrogenase and ATPase. (Adenosine Triphosphatase)
  1. Magnesium is required for the formation of bone and teeth.
  2. Magnesium ion is necessary for proper neuromuscular functions.
  3. Magnesium ion serves as a cofactor for several enzymes requiring ATP such as hexokinase etc.
  4. It is an integral part of certain enzymes such as co-carboxylase.
  5. If functions as a cofactor for oxidative phosphorylation.
  6. It is essential for maintaining osmotic pressure and water balance.
  7. It is present in chlorophyll and hence it is essential for photosynthesis.
  1. Copper is necessary for the synthesis of hemoglobin.
  2. It is required for melanin (the pigment of hair and skin) formation.
  3. It is required for the synthesis of phospholipid and collagen (structural protein0
  4. Development of bone and nervous system requires copper.
  5. Copper is a constitution of several enzymes such as tyrosinase, cytochrome oxidase, ascorbic acid oxidase etc.
  6. It is a constituent of superoxide dismutase (antioxidant) amine oxidase etc.
  7. Hemocyanin, a copper protein complex in invertebrates, functions like hemoglobin for oxygen transport.
  8. Plastocyanins are the copper containing proteins found in photosynthetic organisms.
  9. Azurins are blue copper proteins involved in electron transfer in the respiratory chain of some bacteria.
  1. Zinc is necessary to maintain the normal levels of vitamin A in blood.
  2. Zinc is an essential component of several enzymes such as carbonic anhydrase, alcohol dehydrogenase etc.
  3. The storage and secretion of insulin from pancreas requires zinc.
  4. Zinc is required for wound healing.
  5. Gusten, a zinc containing protein of the saliva is important for taste sensation.
  6. Zinc is essential for proper reproduction.
  7. Superoxide dismutase is a zinc cointaining enzyme. It acts as an antioxident.
  8. Biosynthesis of mononucleotides and their incorporation into the nucleic acids require zinc.
  9. Zinc is essential for normal growth.
  1. Hemoglobin, the heme protein acts as the oxygen carrier from lungs to tissues.
  2. Myoglobin, the heme protein stores the oxygen in the muscle.
  3. There are many heme cointaining enzymes such as catalases, peroxidases etc.
  4. Some enzymes require iron for their activity. Examples: xanthine oxidase, succinate dehydrogenase etc.
  5. Cytochromes are the heme cointaining proteins involved in electron trasnsport chain.
  6. Iron-sulphur proteins such as rubredoxin are involved in electron transfer reactions.
  7. Hemerythrin is an non-heme iron protein used to transport and store oxygen in marine invertebrates.
  1. Manganese is essential for normal bone formation.
  2. It is essential for reproduction and normal growth.
  3. It is essentisl for the synthesis of hemoglobin.
  4. Manganese inhibites lipid peroxidation.
  5. It is required for the normal functioning of central nervous system.
  6. It is necessary for cholesterol biosynthesis.
  7. It is involved in the synthesis of glycoproteins.
  8. It act as a cofactor for many enzymes like enolase, arginase etc.
  1. It is an essential constituent of the enzymes such as xanthine oxidase, aldehyde oxidase etc.
  2. Nitrate reductase is a molybdenum containing plant enzyme required for nitrogen fixation.
  3. It influences copper metabolism.
  4. The bacterial enzyme hydrogenase requires molybdenum for its activity.
  5. This element is essential for plant growth, because of its role in nitrogen fixation.
  1. It is an essential component of vitamin B12.
  2. Enzymes like ribonucleotide reductase require vitamin B12 for activity.
  3. Cobalt is required to maintain normal bone marrow function.
  4. Cobalt containing vitamin B12 ia an essential nutrient for humanbeings.

Thursday, July 8, 2010


PURPOSE : To observe the vibration of a match due to the pulsation of blood in the wrist.

MATERIALS : Modeling clay
                            Paper match

  • Insert the match onto a very small piece of clay ( the smaller the better )
  • Flatten the bottom of the clay.
  • Place your wrist, palm side up, on the table.
  • Place the clay on your wrist, and move the clay around on the thumb side of the wrist until the match starts to slowly vibrate back and forth.
  • Count the number of vibration that the match makes in one minute.
RESULTS :  The match vibrates back and forth with a regular beat. For adult it will vibrate 60 to 80 times in one minute. The vibration for childern is from 80 to 140 beats per minute.

WHY ? As the heart contracts, blood is forced through the blood vessels. The blood moves at a rhythmic rate causing the blood vessels in the wrist to pulsate. All blood vessels have this throbbing motion, but the vessels in the wrist are close to the surface of the skin and can be felt more easily. The movement of the blood under the clay causes it and the match to vibrate.

Wednesday, July 7, 2010


PURPOSE : To measure the amount of air that can be forced out of the lungs.

MATERIALS : Plastic dishpan
                           2 feet ( 61 cm ) of aquarium tubing
                           1 gallon ( 4 liters ) plastic milk jug with cap
                           Masking tape

  • Place the strip of masking tape down the side of the milk jug from top to bottom.
  • Fill the jug with water, and screw on the cap.
  • Fill the dishpan about 1/2 full with water.
  • Place the jug upside down in the water, and remove the cap.
  • Have a helper hold the jug. Do not allow air bubbles to enter the milk jug.
  • Place one end of the aquarium tubing inside the mouth of the jug.
  • Take a normal breath and exhale through the tubing. Mark the water level on the tape.
  • Refill the jug with water and return it to the dishpan.
  • Breath in deeply and make an effort to exhale all of the air out of your lungs through the tubing. Mark the water level on the tape.
RESULTS : The water level drops as exhaled air enters the jug. Normal breathing does not push out as much water as does deep breathing.

WHY ?When the air enters the jug it pushes the water out the opening. In normal breathing, only about one eighth of lungs' capacity is used. During exercise, more air is taken in and exhaled, thus there is a amount of air exhaled during deep breathing.


PURPOSE : To determine the best way to grow penicillin.

MATERIALS : Cotton balls
                           2 oranges
                           2 lemons
                           2 bread sacks

  • Rub the fruit on the floor.
  • Place the fruit in a bowl exposed to the air for one day.
  • Place in each bread sack an orange, a lemon, and a cotton ball wet with water.
  • Secure the ends of the sacks.
  • Place one sack in the refrigerator and the other in a warm dark place.
  • Leave the sacks closed for two weeks.
  • Observe the fruit through the sacks daily.
RESULTS : The fruit in the refrigerator looks the same or possibly a bit dryer, but the other fruit has turned into blue green fuzzy balls.

WHY ? The green powder growth on the outside of the fruit is penicillius. Under a microscope this mold looks like a small brush thus it was named from the latin word penicillus meaning a paint brush. Because brushes were used to write with at one time, our modern writing tool, the pencil, is named after the latin word for paintbrush. Molds can grow in hot places, but they grow faster and in more abundance in moist warm places. This is why foods become more moidy in the summertime. Placing bread in a bread box or on top of a refrigerator causes them to mold more quickly. Cooling foods slows down the growth of mold and freezing keeps foods fresh for much longer periods of time. 


PURPOSE : A water drop is used to simulate an eye lens.

MATERIALS : One 6 inch (15 cm) piece of 20 gauge wire

  • Twist one end of the wire around the pencil to make a round loop.
  • Fill the bowl with water.
  • Dip the wire into the water with the open loop pointing up.
  • Lift the loop carefully out of the water and hold it over the newspaper. You want a large rounded drop of water to stay in the hole of the wire loop.
  • Look through the water drop at the letters on the page. You may have to move the loop up and down to find a position that makes the letter clear.
RESULTS : The letters are enlarger. If the letters look smaller dip the loop into the water again.

WHY ? The water drop is curved outward and acts like a convex lens. This type of lens is used as a magnifying lens and is the type of lens is eyes. Sometimes the water drop stretches so tightly between the wire that it curves downward forming a concave lens. This type of lens causes the letters to look small. 


PURPOSE : To determine your sensitivity to taste.

MATERIALS : Toothpicks
                            Spring type clothespin

  • Cut the apple and onion into small bite size pieces of equal size.
  • Ask a helper to assist you with the experiment. Without seeing or smelling, the person will decide on the identity of the food by taste only.
  • Blindfold the helper and place the clothespin on his or her nose. An old clothespin with a weak spring is best so that it will not pinch too tightly.
  • Use a toothpick to place a piece of apple in the helper's mouth and give instruction to chew it and identify what the food is. It is important that the helper has not seen the food samples before the experiment starts.
  • After making an identification, have your helper remove the nose clip and compare the taste when odor is included.
  • Replace the clip and blindfold then use a toothpick to place the onion poece in your helper's mouth.
  • Ask for an identification.
  • Remove the clip and again ask for an identification.
RESULTS : Without smelling the apple and onion have a similar taste. The texture of the food will give clues, but the taste is the same.

WHY? The tongue has nerve ending that allow one to taste things that are sweet, sour, salty, or bitter. Most of the taste sensations experienced are due to smell. Make a note of how tasteless food seems the next time you have a cold and cannot breath properly.


PURPOSE : To demonstrate the semi-permeability of a cell membrane.

MATERIALS : 1 raw egg in its shell
                           1 Jar with a lid ( the egg must fit inside the jar )
                           Clear vinegar
                           Flexible measuring tape

  • Measure and record the circumference around the center of the egg.
  • Record the apperance of the egg.
  • Place the egg inside the jar. Do not crack the shell.
  • Cover the egg with vinegar.
  • Close the lid.
  • Observe immediately and then periodically for the next 72 hours.
  • Remove the egg after 72 hours and measure its circumference.
  • Compare the appearence of the egg before and after being in the vinegar.
  • How has the egg changed in appearence and size?
RESULTS : The egg has a hard shell on the outside and the circumference will vary. Bubbles start forming on the surface of the egg's shell immediately and increase in number with time. After 72 hours the shell will be gone and portions of it may be seen floating on the surface of the vinegar. The egg remains intact because of the thin see-through membrane. The size of the egg has increased.

WHY ? The shell of the egg is made of calcium carbonate, commonly called limestone. When vinegar reacts with the limestone, one of the products is carbon dioxide gsa, those bubbles seen on the egg.The membrane around the egg does not dissolve in vinegar, but becomes more rubbery. The increased size is due to osmosis, the movement of water through a cell membrane. The water in the vinegar moves through the thin membrane onto the egg because the water inside the egg has more materials dissolved in it than does the vinegar. Water will always move through a membrane in the direction where there are more dissolved materials. The contents of the egg stayed inside the membrane because these molecules were too large to pass through the tiny holes. This selectiveness of materials moving through the membrane is called semi-permeability.  

Tuesday, July 6, 2010


PURPOSE : To demonstrate the effect that temperature has on the growth of bacteria.

                        Measuring cup (250ml)
                        2 (500 ml) jars

  • Put a cup of milk in each jar
  • Close each jar.
  • Place one jar in the refrigerator.
  • Place the second jar in a warm place.
  • Examine the milk in each jar once for 7 days.
RESULTS : The warm milk has thick, white lumps in it and smell sour. The cold milk looks and smells like drinkable milk.

WHY ? Warm temperature promote the growth of bacteria that can cause food to spoil. Cooler temperature slow down the bacteria growth, but milk will eventually spoil if left in the refrigerator long enough. The bacteria are present and grow very slowly when cold, but they do grow.


PURPOSE : To determine the effect of sunlight on plant survival.

MATERIALS : House plant 
                          Black construction paper
                          Tape (cellophane)

  • Cut two piece of black construction paper large enough to civer one leaf on the plant.
  • Sandwich the leaf between the two paper pieces.
  • Tape the paper together. It is important that the leaf not receive any sunlight.
  • Wait 7 days.
  • Uncover the leaf and observe its color.
RESULTS : The leaf is much paler than the other leaves on the plant.

WHY ? A green chemical called chlorophyll gives leaves their green color. In the absence of sunlight the green pigment is used up and not replenished in the leaf resulting in a light colored leaf. Since chlorophyll is necessary for plant survival the leaf will die without sunlight.


PURPOSE : To determine which side of the plant leaf takes in gases.

MATERIALS : Potted plant


  • Coat the top of four leaves with a heavy layer of vaseline.
  • Coat the under side of four leaves with a heavy layer of vaseline.
  • Observe the leaves daily for one week.
  • Is there any difference in the two sets of leaves ?
RESULTS : The leaves that had vaseline coated on the underside died. The other leaves remained unchanged.

WHY ? Openings on the under side of the plant leaves called stomata allow gases to move into and out of the leaves. The vaseline plugged the openings and the leaf was not able to receive necessary carbon dioxide gas or eliminate excess oxygen gas. 


PURPOSE : To demonstrate that starch, a food substance, is produced in leaves.

MATERIALS : Paper towels
                          Tincture of iodine
                          Leaf ( pale green )
                          Rubbing alcohol
                          Shallow dish
                          ( 500 ml ) jar with lid
                           Measuring cup ( 250 ml )


  • Place the pale green leaf in the jar. The paler the leaf , the easier it will be to extract the green pigment, chlorophyll.
  • Pour one cup of alcohol into the jar. Put the lid on the jar.
  • Allow the jar to stand for one day.
  • Remove the leaf and dry it by blotting with a paper towel.
  • Lay the leaf in the shallow dish.
  • Add enough iodine to cover the leaf.
RESULTS : Dark areas appear on the leaf.

WHY ? Photosynthesis is an energy producing reaction that occurs in the leaves of plants. Starch, a food substance is one of the product of this reaction. Soaking the leaf in alcohol removes the wax coating on the leaf plus it partially removes the green pigment chlorophyll. It is easier to see the result of the starch test without the presence of the green chlorophyll. Iodine combines with starch particles to form a dark purple to black color. 


PURPOSE : To demonstrate that the leave and stem of plants can act like a straw.

MATERIALS : Glass soda bottle
                           Ivy leaf and stem


  • Fill the bottle to within an inch of its top.
  • Wrap the clay around the stem near the leaf.
  • Place the stem into bottle. The end of the stem must be below the surface of the water.
  • Cover the mouth of the bottle with the clay.
  • Push the pencil through the clay to make an opening for the straw.
  • Insert the straw so that its opening is in the air space at the top of the bottle.
  • Squeeze the clay around the straw.
  • Stand in front of the mirror and look at the mirror image of the bottle while you suck the air out of the bottle through the straw.This should be difficult if there are no leaks in the clay so use a lots of suction.
RESULTS : Bubbles start forming at the bottom of the stem.

WHY ? There are holes in the leaf called stomata, and tiny tubes called xylem run down the stem. The leaf and stem acted like a straw. As you sucked air out of the straw through the leaf straw. It is through these tubes and holes that water moves in a plant.


PURPOSE : To demonstrate how water is transported through plant stems.

MATERIALS : Measuring cup (250 ML)
                           2 Glasses
                           1 White carnation with long stem ( purchase at a floral shop )
                            Red and yellow food coloring 

  • Cut the stem in half lengthwise from the bottom to about half way up toward the flower.
  • Pour 1/2 cup of water into each glass. 
  • Add enough food coloring to make the water in each glass a deep color, one will be red and the other yellow.
  • Place one end of the flower stem in the red water and the other end in the yellow water.
  • Leave the flower standing in the water for 48 hours.
RESULTS : After 48 hours , the flower will have changed color. One side will be red and the other yellow.

WHY ? Tiny tubes, called xylem run up the stalk to the flower petals. The colored water moves through the xylem allowing the color to be distributed throughout the cells in the petals causing their color to change. Minerals in the soil are carried to plant cell in this way providing in water as did the red and yellow coloring and the solution is carried up to the leaves and flowers where the dissolved material is left as was the red and yellow dye.