Carbohydrates:

GALACTOSEMIA

Members: Asst.Prof Glen Mangali

Alarcon, Ma. Jhuzel

Cimafranca, Allyza Jean

Desengano, Karen Anne

Janer, Christelle

Mejia, Maxiene

Perez, Janine

Tajanlangit, Robelle

Topic Outline:

I. Objectives

II. Overview

III. Galactosemia

A. What is Galactose?

B. What is Galactosemia?

1. Symptoms

2. Signs and Tests

3. Treatment

4. Prevention

5. Inheritance (Christelle Janer)

C. Types of Galactosemia

1. Galactosemia I (Jhuzel Alarcon)

2. Galactosemia II (Karen Desengano)

3. Galactosemia III (Allyza Jean Cimafranca)

IV. L-ascorbic acid and L-dehydroascorbic acid

A. L-Ascorbic acid (Karen Desengano)

B. L-dehydroascorbic acid (Jhuzel Alarcon)

V. Glucose Assay

A. Procedure

1. Contents

2. Chromogen Reagent (GOPOD) Preparation

3. Assay Condition

VI. The Significance of L-Fucose in blood (Maxiene Mejia)

VII. Technologies related to Carbohydrates

A. Carbohydrate Microarrays ( Allyza Jean Cimafranca)

B. Carbohydrate Analysis by IC and HPLC (Robelle Tajanlangit)

C. Sony Bio Battery (Janine Perez)

(Jhuzel Alarcon)

(Maxiene Mejia)

(Janine Perez)

(Robelle Tajanlangit)

(Christelle Janer)

Galactosemia

Objectives:

At the end of the lecture, you should be able to:

a. define galactosemia and know its characteristics; b. identify its types of galactosemia; c. explain the mode of inheritance of galactosemia;d. enumerate the symptoms, signs and tests, treatments, and prevention of galactosemia;e. explain the difference between L-ascorbic and L-dehydroascorbic acid;f. analyze how glucose assay is used in clinical chem lab;g. find out the importance of l-fucose in blood typing; andh. integrate technologies used related to Carbohydrates at the present

Overview:

Galactosemia is an inherited disorder characterized by an inability of the body to utilize galactose. Galactosemia means "galactose in the blood ". Galactose is a type of food sugar found mainly in dairy products, and is produced within the body as well. The main source of galactose in the diet is milk products. Milk contains a sugar called lactose, and during digestion, lactose is broken down into the sugars glucose and galactose. Glucose can be used as a source of energy by the body, but galactose needs to be further broken down by a specific chemical (enzyme) before it can be utilized. Persons with galactosemia have very little or entirely lack an enzyme that helps the body break down galactose. There are three different enzyme problems that can lead to galactosemia.

Galactosemia is treated by removing foods that contain galactose from the diet. Any foods containing lactose, thereby containing galactose, should be avoided. Untreated galactosemia will result in a harmful build-up of galactose and galactose-1-phosphate (a form of galactose) in the bloodstream and body tissues. Infants with unrecognized galactosemia usually have problems with feeding and do not grow as they should. If galactosemia is not treated, infants can develop cataracts, liver disease and kidney problems. In addition, the build-up of galactose and galactose-1-phosphate can cause brain damage, and in some cases, can lead to death. Even with treatment, some children may develop learning disabilities, and girls with galactosemia may have problems with their ovaries. With continued dietary management, however, many individuals with galactosemia enjoy good health, and are able to lead independent lives.

What is Galactose?

Galactose (Gal) (also called brain sugar) is a type of sugar which is less sweet than glucose and not very water-soluble.

It is considered a nutritive sweetener because it has food energy. It is found in dairy products, in sugar beets and other gums and mucilages. It is also synthesized by

the body, where it forms part of glycolipids and glycoproteins in several tissues. Produced when lactose is broken down in the body

What is Galactosemia?

Galactosemia is an inherited disease in which the transformation of galactose to glucose is blocked, allowing galactose to increase to toxic levels in the body.

It is a condition in which the body is unable to use (metabolize) the simple sugar galactose.

It is also known as Galactose-1-phosphate uridyl transferase deficiency; Galactokinase deficiency; Galactose-6-phosphate epimerase deficiency

This shows the normal process of breaking down of lactose and in galactosemia wherein there is a malfunction in the GALT enzyme causing build up of galactose instead of

Galactosemia is an inborn error of metabolism. (“Metabolism" refers to all chemical reactions that take place in living organisms.) Inborn errors of metabolism are caused by mutations in these genes which do not allow the enzymes to function properly.

Classic galactosemia occurs in 1 in 30,000 to 60,000 newborns. Galactosemia type II and type III are less common; type II probably affects fewer than 1 in 100,000 newborns and type III appears to be very rare.

Galactosemia I Extrapolated StatisticsExtrapolated Prevalence

Population Estimated

World 319,681 6,973,738,433Asia 125,031 4,164,252,000

Philippines 2,874 94,852,030(NOTE: These prevalence extrapolations for Galactosemia I are only estimates, based on applying the prevalence rates from the US (approx 1 in 30,000) to the population of other countries, and therefore may have very limited relevance to the actual prevalence of Galactosemia I in any region)

Galactosemia is a rare but potentially life-threatening disease

If an infant with galactosemia is given milk, substances made from galactose build up in the infant's system. This is important for infants because they typically get most of their nutrient energy from milk, which contains a high level of galactose. Each molecule of lactose, the major sugar constituent of milk, is made up of a molecule of galactose and a molecule of glucose, and so galactose makes up 20% of the energy source of a typical infant's diet.

Three enzymes are required to convert galactose into glucose-1-phosphate (a phosphorylated glucose that can enter the metabolic pathway that turns glucose into energy). Each of these three enzymes is encoded by a separate gene. If any of these enzymes fail to function, galactose build-up and galactosemia result.

Symptoms:

Infants with galactosemia can develop symptoms in the first few days of life if they eat formula or breast milk that contains lactose. The symptoms may be due to a serious blood infection with the bacteria E. coli.

*Convulsions *Irritability

* Lethargy *Poor feeding (baby refuses to eat formula containing milk)

* Vomiting *Poor weight gain

* Yellow skin and whites of the eyes (jaundice)

Signs and tests:

Signs include:

Amino acids in the urine and/or blood plasma (aminoaciduria) Enlarged liver (hepatomegaly) Fluid in the abdomen (ascites) Low blood sugar (hypoglycemia)

Newborn screening in many states will test for this condition.

Tests include:

Blood culture for bacteria infection (E. coli sepsis)

- A blood culture is a laboratory test to check for bacteria or other microorganisms in a blood sample. A culture may be done using a sample of blood, tissue, stool, urine, or other fluid from the body. The sample is sent to a laboratory, where it is placed in a special dish and watched to see if germs grow. This is called a culture. Most cultures check for bacteria. If bacteria does grow, further tests will be done to identify the specific type.

Enzyme activity in the red blood cells

Ketones in the urine

- Ketones build up when the body needs to break down fats and fatty acids to use as fuel. This is most likely to occur when the body does not get enough sugar or carbohydrates. A urine test can be done to check the level of ketones in your body. For infants, thoroughly wash the area around the urethra. Open a urine collection bag (a plastic bag with an adhesive paper on one

end), and place it on the infant. For boys, the entire penis can be placed in the bag and the adhesive attached to the skin. For girls, the bag is placed over the labia. Diaper as usual over the secured bag. This procedure may take a couple of attempts -- lively infants can displace the bag. The infant should be checked frequently and the bag changed after the infant has urinated into the bag. The urine is drained into the container for transport to the laboratory. Urine ketones are usually measured as a "spot test" using a dipstick coated with chemicals that react with ketone bodies. The dipstick is dipped in the urine sample, and a color change indicates the presence of ketones.

Prenatal diagnosis by directly measuring the enzyme galactose-1-phosphate uridyl transferase

- This test measures the amount of an enzyme called galactose-1-phosphate uridyltransferase in blood. It is used for suspected cases of galactosemia. A sample of venous, capillary, or umbilical cord blood may be collected for this test.

a.) Venous Blood:

When a blood sample from a vein is needed, a vein in your arm is usually selected. A tourniquet (large rubber strap) may be secured above the vein. The skin over the vein will be cleaned, and a needle will be inserted. You will be asked to hold very still while your blood is collected. Blood will be collected into one or more tubes, and the tourniquet will be removed. When enough blood has been collected, the healthcare worker will take the needle out.

b.) Capillary blood:

Common sites to collect a capillary blood sample are the fingertip and earlobe. Infants often have a capillary blood sample taken from the heel of the foot. Once the site is selected, the healthcare worker may heat the area with a warm compress to ensure adequate blood flow. The area will be cleaned with antiseptic. A small needle is used to make a cut in the skin surface, and the area may be squeezed gently to produce blood. The blood is collected in small collection device.

c.)Umbilical cord blood:

To collect an umbilical cord blood sample after an infant is born, the healthcare worker may use a needle and syringe to draw blood from the umbilical cord while the cord is still attached to the infant. Blood samples may also be collected from the part of the umbilical cord that has been detached from the infant. After birth, an infant's body does not need the attached umbilical cord stump or its blood vessels, but they may be used temporarily for medical purposes. If the infant has a catheter inserted in a vessel of the umbilical cord, the blood sample may be collected through the existing catheter.

"Reducing substances" in the infant's urine, and normal or low blood sugar while the infant is being fed breast milk or a formula containing lactose.

- This is a screening test to detect various substances in the urine that chemically react with an indicator metallic dye called cupric sulfate. The most common reducing substances examined include glucose or galactose. For an infant, thoroughly wash the area around the urethra. Open a urine collection bag (a plastic bag with an adhesive paper on one end), and place it on your infant. For males, the entire penis can be placed in the bag and the adhesive attached to the skin. For females, the bag is placed over the labia. Place a diaper over the infant (bag and all). Check your baby frequently and remove the bag after the infant has urinated into it. For active infants, this procedure may take a couple of attempts -- lively infants can displace the bag, causing an inability to obtain the specimen. The urine is drained into a container for transport back to the health care provider. A Clinitest tablet is placed in a sample of the urine. If urinary reducing substances (glucose, galactose, or other reducing substances) are present, the urine will turn orange.

Treatment:

Once the disease is recognized, treatment consists of strictly avoiding all milk, milk-containing products, and other foods that contain galactose. The infant can be fed with soy formula, meat-base formula, or Nutramigen (a protein hydrolysate formula), or other lactose-free formula.

The condition is lifelong and requires abstinence from milk, milk products, and galactose-containing foods for life. Calcium supplements are recommended.

Parents need to take care and educate the child to avoid not only milk and milk products, but also those foods that contain dry milk products. For this reason, it is essential to read product labels and be an informed consumer.

Prevention:

For couples with a previous child with galactosemia, prenatal diagnosis is available to determine whether a pregnancy is similarly affected.

Families in which a child has been diagnosed with galactosemia can have DNA testing which can enable other more distant relatives to determine their carrier status.

Prospective parents can then use that information to conduct family planning or to prepare for a child with special circumstances.

Children born with galactosemia should be put on a diet right away, to reduce the symptoms and complications of disease.

Many states screen all newborns for galactosemia. If parents learn that the test indicates possible galactosemia, they should promptly stop giving their infant milk products and ask their health care provider about having a blood test done for galactosemia.

How is it inherited?

Every cell in a person's body has two copies of each gene. Each of the forms of galactosemia is inherited as a recessive trait, which means that galactosemia is only present in individuals with two mutated copies of one of the three genes. This also means that carriers, with only one copy of a gene mutation, will not be aware that they are carrying a mutation (unless they have had a genetic test), as it is masked by the normal gene they also carry and they have no symptoms of the disease. For each step in the conversion of galactose to glucose, if only one of the two copies of the gene controlling that step is normal (i.e. for carriers), enough functional enzyme is made so that the pathway is not blocked at that step. If a person has galactosemia, both copies of the gene coding for one of the enzymes required to convert glucose to galactose are defective and the pathway becomes blocked. If two carriers of the same defective gene have children, the chance of any of their children getting galactosemia (the chance of a child getting two copies of the defective gene) is 25% (one in four) for each pregnancy.

Types of Galactosemia:

A.Galactosemia I (GALT Deficiency)

Galactosemia I (also called classic galactosemia), the first form to be discovered, is caused by defects in both copies of the gene that codes for an enzyme called galactose-1-phosphate uridyl transferase (GALT).

Newborns with galactosemia I appear normal at birth, but begin to develop symptoms after they are given milk for the first time. Symptoms include vomiting, diarrhea, lethargy (sluggishness or fatigue), low blood glucose, jaundice (a yellowing of the skin and eyes), enlarged liver, protein and amino acids in the urine, and susceptibility to infection, especially from gram negative bacteria. Cataracts (a grayish white film on the eye lens) can appear within a few days after birth.

People with galactosemia frequently have symptoms as they grow older even though they have been given a galactose-free diet. These symptoms include speech disorders, cataracts, ovarian atrophy, and infertility in females, learning disabilities, and behavioral problems.

B.Galactosemia II (GALK Deficiency)

It is caused by defects in both copies of the gene that codes for an enzyme called galactokinase (GALK).

Babies born with galactosemia II will develop cataracts at an early age unless they are given a galactose-free diet. They do not generally suffer from liver damage or neurologic disturbances. Galactosemia II is less harmful than galactosemia I.

C.Galactosemia III (GALE Deficiency)

Galactosemia III is caused by defects in the gene that codes for an enzyme called uridyl diphosphogalactose-4-epimerase (GALE). This form of galactosemia is very rare. The benign form has no symptoms and requires no special diet.

The severe form has symptoms similar to those of galactosemia I, but with more severe neurological problems, including seizures.

L-ascorbic acid and L dehydroascorbic acid

L-Ascorbic acid

Ascorbic acid is a naturally occurring organic compound with antioxidant properties. It is a white solid, but impure samples can appear yellowish. It dissolves well in water to give mildly acidic solutions. Ascorbic acid is one form ("vitamer") of vitamin C. It was originally called L-hexuronic acid, but when it was found to have vitamin C activity in animals ("vitamin C" being defined as a vitamin activity, not then a specific substance), the suggestion was made to rename L-hexuronic acid.

Vitamin C, also known as L-ascorbic acid,ascorbic acid or L-ascorbate is a vital nutrient for many animals, including humans. It is an antioxidant which protects the body against oxidative stress. An antioxidant is a molecule that can inhibit the oxidation of other molecules. Oxidation reactions produce free radicals which can start chain reactions that damage cells. It is also a cofactor in 8 enzymatic reactions.

Vitamin C is found principally in vegetables and fruit. We need vitamin C to maintain and form bones, skin and blood vessels.

An organic compound. This means it contains the elements carbon and oxygen and is a substance that exists in living things.

Is involved in the production of collagen. Collagen is the main component of connective tissue and the most abundant protein in mammals. Experts say that 1% to 2% of muscle tissue is collagen. Collagen is a vital and abundant component of fibrous tissues, such as tendon, ligament, skin, cornea, cartilage, bone, the gut, and blood vessels.

Plays a significant role in the healing of wounds, cuts and grazes.

individuals with adequate levels of vitamin C are better able to fight off infections compared to people with vitamin C deficiency.

Vitamin C slows down the conversion of irritants into cancer-causing substances. Examples of irritants include tobacco smoke, smog, and some substances found in foods.

Experts believe vitamin C widens the blood vessels, protecting us from developing hypertension (high blood pressure) and heart disease.

Individuals with adequate levels of vitamin C have better cholesterol level control compared to others.

if you consume plenty of vitamin C you will not get scurvy, a disease that causes swollen joints, bleeding gums, loose teeth, anemia and tiredness. Scurvy used to be a problem among ship crews many years ago because of a lack of fruit and vegetable consumption. Today scurvy is uncommon.

Vitamin C lowers the risk of cataracts.

L-dehydroascorbic Acid

Dehydroascorbic acid (DHA) is an oxidized form of ascorbic acid. It is actively imported into the endoplasmic reticulum of cells via glucose transporters. It is trapped therein by reduction back to ascorbate by glutathione and other thiols. Therefore, L-dehydroascorbic acid is a vitamin C compounds much like L-ascorbic acid. The (free) chemical radical semidehydroascorbic acid (SDA) also belongs to the group of oxidized ascorbic acids.

Dehydroascorbic acid readily enters the brain and is retained in the brain tissue in the form of ascorbic acid (ascorbic acid is not able to cross the blood-brain barrier). Therefore, transports of dehydroascorbic acid by the Glucose Transporter 1 (GLUT1, Glucose transporters) are integral membrane glycoproteins involved in transporting glucose into most cells.

GLUT1 is a major glucose transporter in the mammalian blood-brain barrier. It is present at high levels in primate erythrocytes and brain endothelial cells.) is a mechanism by which the brain acquires vitamin C. (OMIM 138140)

Glucose Assay

Glucose is a simple sugar, also known as a monosaccharide that circulates in the bloodstream, providing all cells in the body with the fuel they need for essential functions.

Glucose assay, sometimes called a glucose test, is the process of analyzing a substance to determine if it contains glucose, and if so in what concentration.

In medicine, a glucose assay is most commonly used to measure the concentration of glucose in the body to diagnose and manage metabolic problems, such as diabetes. Samples of either urine or blood can be used to do medical glucose assays, but the serum derived from blood samples gives the most accurate results.

There are several different ways to perform a glucose assay, but the two main types are chemical assays, which are relatively cheap and easy to perform, and the newer enzymatic assays, which are more accurate but also require more time and resources.

Doctors most often perform glucose assays to diagnose diabetes, hyperglycemia, or highblood glucose levels, and hypoglycemia, or low blood glucose levels. One common test done for this purpose is called a glucose tolerance test. In this test, the glucose assay is done to analyze how quickly a certain amount of glucose is metabolized by the body. A fasting blood sugar test can also be used for similar purposes. It assays the glucose level in the blood after 12 hours of fasting and is commonly done to test for gestational diabetes.

Monitoring glucose levels in people diagnosed with diabetes is another common use for glucose assays. A person with diabetes has higher than normal levels of glucose which can lead to serious disease and death. To help maintain a normal blood glucose level, a small blood sample is taken frequently and a glucose assay is used to determine the concentration of glucose in the blood. A glucose meter is often used to perform this glucose assay. 

Glucose assays can also be performed for non-medical purposes, for example to analyze the sugar content of plant extracts and of various goods in the food industry.

The most common chemical method of performing a glucose assay is the dinitrosalicylic acid (DNS) assay, which was first introduced in 1955. More accurate enzymatic glucose assay methods have been developed and are more commonly used in medicine today. Enzymatic assays use various reactive compounds called reagents to determine glucose levels. A common reagent used is glucose oxidase, a substance usually extracted from certain species of mold.

Procedure

KITS:

Kits suitable for performing 500 assays are available from Megazyme and consist of:1. Glucose Determination Reagent (for 2 x 1 litres of reagent)2. Glucose Reagent Buffer (for 2 x 1 litres of reagent)3. Glucose Standard Solution

CONTENTS:

Glucose Reagent Buffer (Concentrate):1 M Potassium dihydrogen orthophosphate200 mM p-hydroxybenzoic acid0.4% sodium azideStore at 2-5oC (12 months) or at -20oC (>12 months).Glucose Determination Reagent (per vial):Glucose oxidase >12,000UPeroxidase >650 U4-Aminoantipyrine 0.4 m molesStore at 2-5oC (12 months) or at -20oC (>12 months).Glucose Standard:Glucose 1.0 mg/mLBenzoic acid 0.2% w/v

CHROMOGEN REAGENT (GOPOD) PREPARATION:1. Dilute 50.0 mL (1 container) of the Glucose Reagent Buffer (concentrate) to 1 Litre with distilled water.Note:When stored at -20oC, the buffer will crystallise. Ensure all crystalline material is dissolved in the 1 litre of distilled water.2. Dissolve the contents of one vial of Glucose Determination Reagent in this buffer.3. This GOPOD reagent in a brown storage bottle is stable for:3 months at 2-5oC >12 months in the frozen state

When this reagent is freshly prepared it may be light yellow or light pink in colour. It will develop a stronger pink colour over 2-3 months at 4oC.The absorbance of this solution should be less than 0.05 when read against distilled water.

ASSAY CONDITIONS:

Wavelength: 510 nm (492-550)Temperature: 40oC or 50oCLight path: 1 cmZero: Reagent Blank

ASSAY PROCEDURE:BLANK STANDARD SAMPLE

BLANK STANDARD SAMPLEChromogen reagent

Glucose standardSample

Buffer or water

3 mL--

0.2 mL

3 mL0.1 mL

-0.1 mL

3 mL-

0.1 mL0.1 mL

Mix and incubate at 40 or 50oC for 20 min. Read absorbance(O.D.) at 510 nm against the reagent blank.

CALCULATION:Glucose, µg/0.1 mL = (O.D. Sample/ O.D. Standard (glucose, 100 µg)) x 100

The Significance of L-Fucose in blood

Fucose is a hexose deoxy sugar with the chemical formula C6H12O5. It is found on N-linked glycans on the mammalian, insect and plant cell surface, and is the fundamental sub-unit of the fucoidan polysaccharide. α(1→3) linked core fucose is a suspected carbohydrate antigen for IgE-mediated allergy.

Two structural features distinguish fucose from other six-carbon sugars present in mammals: the lack of a hydroxyl group on the carbon at the 6-position (C-6) and the L-configuration. It is equivalent to 6-deoxy-L-galactose.

In the fucose-containing glycan structures, fucosylated glycans, fucose can exist as a terminal modification or serve as an attachment point for adding other sugars. In human N-linked glycans, fucose is most commonly linked α-1,6 to the reducing terminal β-N-acetylglucosamine. However, fucose at the non-reducing termini linked α-1,2 to galactose forms the H antigen, the substructure of the A and B blood group antigens. Fucose is metabolized by an enzyme called α-fucosidase.

L-Fucose is claimed to have application in cosmetics, pharmaceuticals, and dietary supplements. Milk from women with blood typeLe(a +) or Le(b +) contains a specific fucosyltransferase not found

in the milk of women with blood typeLe(a - b -). The enzyme, a guanosine diphosphate L-fucose: N-acetyl-1-i-glucosaminylsaccharide a-4-L-fucosyltransferase is apparently required for the synthesis of the structural determinants of Lea and Leb specificity, both of which contain fucose in an a-1,4 linkage to N-acetylglucosamine. The same enzyme is also involved in the synthesis of milk oligosaccharides, as two oligosaccharides which contain this linkage are absent from the milk of women with Le (a - b -) blood type.

Technologies related to Carbohydrates

I. Carbohydrate Microarrays – a new set of technologies at the frontiers of glycomics

Carbohydrate microarray technologies are new developments at the frontiers of glycomics. Results of 'proof of concept' experiments with carbohydrate-binding proteins of the immune system - antibodies, selectins, a cytokine and a chemokine - and several plant lectins indicate that microarrays of carbohydrates (glycoconjugates, oligosaccharides and monosaccharides) will greatly facilitate not only surveys of proteins for carbohydrate-binding activities but also elucidation of their ligands.

It is predicted that both naturally occurring and synthetic carbohydrates will be required for the fabrication of microarrays that are sufficiently comprehensive and representative of entire glycomes.

New leads to biological pathways that involve carbohydrate-protein interactions and new therapeutic targets are among biomedically important outcomes anticipated from applications of carbohydrate microarrays.

II. Carbohydrate Analysis by IC and HPLC

High Performance Liquid Chromatography (HPLC) is an important tool to identify and quantify carbohydrates in food and beverage samples, providing key metrics of product quality and related properties, contamination, or adulteration. HPLC plays important roles in quality control, nutritional labeling, authenticity testing, and production processes monitoring, for example, tracking the fermentation of alcoholic beverages.

Separation and detection in high-concentration carbohydrate mixtures, as found in the food and beverage industry, do made challenging by the wide variety of carbohydrate molecules and intricacy of carbohydrate mixtures exist in nature. Selection of the optimal HPLC approach depends on the sample matrix, carbohydrate concentration, selectivity, and sensitivity required.

HPLC on aminopropyl-bonded silica or polymer-based metal-loaded cation-exchange resins, in conjunction with refractive index (RI) or low wavelength UV detection, provide simple isocratic methods. In most cases, HPLC on metal-loaded cation-exchange resins with RI detection (HPLC-RI) is used to determine simple mono- and disaccharides in the g/L range.

However, some sample matrices require better resolution of sugars from sugar alcohols, organic acids, and sodium chloride.

High-performance anionexchange chromatography with pulsed amperometric detection (HPAE-PAD) and specialized CarboPac® columns solve these chromatographic and selectivity issues, while also allowing the determination of alcohols, glycols, and aldehydes. HPAE-PAD can separate sugars, sugar alcohols, oligo-, and polysaccharides with very high resolution, without derivatization or pre-concentration. This approach provides quantification to picomolar levels.

III. Sony Bio Battery

Energy (obtained from food through enzymatic reactions) is the basis of human movement. Enzymes are special proteins that facilitate chemical reactions inside our bodies. Sony's Bio Battery uses this same principle to produce electric energy. It is an extremely safe form of energy production since the fuel (glucose) is a carbohydrate just like bread or rice. Because glucose is a clean energy source---produced by plants through photosynthesis (a process that involves the absorption of CO2)---Bio Battery is also an eco-battery. Sony commenced Bio Battery R&D in 2001. Bio Battery extracts energy directly from a carbohydrate (glucose) using the power of enzymes, which play a central role in systems used by many living organisms to obtain energy.

Sony pioneered the development of cells based on this technology, and (in August 2007) was able to operate a Walkman using four cells arranged in series producing 50mW/40cc (1.25mW/cc) per unit .

Like a conventional fuel cell battery, Bio Battery basically consists of an anode, cathode, electrolyte and separator. However, Bio Battery has certain specific characteristics. First, biological enzymes are used as catalysts for the anode and cathode. Second, enzymes and electronic mediators (which

transfer electrons between enzymes, and between enzymes and electrodes) are fixed on the anode and cathode.

How the Bio Battery Works

Glucose is broken down on the anode side of the battery, producing protons (H+) and electrons (e-). The protons (H+) are transferred to the cathode side through the separator, while the electrons (e-) are transported to the cathode side through the mediator, which transfers them to the external circuit. The cathode uses the enzymes to drive an oxygen-reduction reaction which ultimately produces water using both the protons (H+) and the electrons (e-) transferred from the anode. These reactions at the anode and cathode generate electric energy by creating proton (H+) and electron (e-) flow in the cell system.

References:

http://en.wikipedia.org/wiki/Dehydroascorbic_acidhttp://en.wikipedia.org/wiki/Ascorbic_acidhttp://www.glyconutritionforlife.org/Science_of_Glyconutrients/Galactose.phphttp://ghr.nlm.nih.gov/condition/galactosemiahttp://en.wikipedia.org/wiki/Galactosehttp://www.nlm.nih.gov/medlineplus/ency/article/000366.htmhttp://en.wikipedia.org/wiki/Galactosemiahttp://galactosemia.org/Understanding_Galactosemia.phphttp://www.ncbi.nlm.nih.gov/books/NBK51671/http://www.wisegeek.com/what-is-a-glucose-assay.htmhttp://www.sony.net/SonyInfo/technology/technology/theme/bio_01.htmlhttp://www.ncbi.nlm.nih.gov/pubmed/14568620http://www.dionex.com/en-us/webdocs/61831-Bro_Carbohydrates_Food_Beverage_29Aug2007_LPN1971.pdfhttp://ada.communityisoft.com/default.asphttp://en.wikipedia.org/wiki/Classic_galactosemiahttp://en.wikipedia.org/wiki/Galactokinase_deficiencyhttp://en.wikipedia.org/wiki/Galactose_epimerase_deficiencyhttp://www.rightdiagnosis.com/g/galactosemia_i/stats-country.htm

QUIZ (Galactosemia)

Multiple ChoiceEncircle the letter of the correct answer.

1. It is caused by defects in both copies of the gene that codes for an enzyme called galactose-1-phosphate uridyl transferase

a. Galactosemia I (GALT Deficiency)b. Galactosemia II (GALK Deficiency)c. Galactosemia III (GALE Deficiency)d. Galactosemia

2. It is found on N-linked glycans on the mammalian, insect and plant cell surface, and is the fundamental sub-unit of the fucoidan polysaccharide.a. Dehydroascorbicb. Ascorbicc. Fucosed. Galactose

3. The most common chemical method of performing a glucose assaya. Dinitrosalicylic acid (DNS) Assayb. Enzymatic Assayc. Chemical Assayd. Biological Assay

4. An inherited disease in which the transformation of galactose to glucose is blocked, allowing galactose to increase to toxic levels in the body.a. Hyperglycemiab. Galactosemiac. Lactose Intoleranced. Cancer

5. It is caused by defects in the gene that codes for an enzyme called uridyl diphosphogalactose-4-epimerasea. Galactosemiab. Galactosemia I (GALT Deficiency)c. Galactosemia II (GALK Deficiencyd. Galactosemia III (GALE Deficiency)

6. A naturally occurring organic compound with antioxidant properties.a. Ascorbicb. Dehydroascorbicc. Fucosed. Glucose

7. The process of analyzing a substance to determine if it contains glucose, and if so in what concentration.a. Glucose Testb. Glucose Assayc. Glucose Tolerance Testd. Ketones in the urine Test

8. An oxidized form of ascorbic acid that is actively imported into the endoplasmic reticulum of cells via glucose transporters. a. L-hexuronic acid

b. Dehydroascorbic acid c. Fucose d. Galactosemia

9. A type of sugar which is less sweet than glucose and not very water-soluble reduced when lactose is broken down in the body a. Galactose b. Sucrose c. Fructose d. Glucose

10. An important tool to identify and quantify carbohydrates in food and beverage samples,

providing key metrics of product quality and related properties, contamination, or adulteration.

a. Carbohydrate Microarrays b. High Performance Liquid Chromatography (HPLC) c. Glucose Assay d. Sony Bio Battery

True or False

__________11. There are several different ways to perform a glucose assay, but the two main types are nitric assays and enzymatic assays.

___________12. . If a person has galactosemia, both copies of the gene coding for one of the enzymes required to convert glucose to galactose are defective and the pathway becomes blocked

___________13. Babies born with galactosemia II will develop diabetes at an early age unless they are given a galactose-free diet.

___________14. Dehydroascorbic acid readily enters the brain and is retained in the brain tissue in the form of ascorbic acid

___________15. Children born with galactosemia should be put on a diet right away

Answer Key:

1. a. Galactosemia I (GALT Deficiency)2. c. Fucose3. a. dinitrosalicylic acid (DNS) assay4. b. Galactosemia5. c. Galactosemia III6. a. Ascorbic acid7. b. Glucose assay8. b. dehydroascorbic Acid9. a. Galactose10.b. High Performance Liquid Chromatography (HPLC)

11. False (chemical)

12. True

13. False ( cataracts )

14. True

15. True