Vitamin B2 (Riboflavin)

Definition

            Riboflavin is digestible micronutrients and one of water soluble vitamins. Riboflavin is a component of two coenzymes; flavin monocleotide (FMN) and flavin adenine dinucleotide (FAD).  FAD and FMN function as tightly bound prosthetic groups in a class of coenzymes known as flavoproteins.

Structure of Riboflavin

            IUPAC name : 7,8-Dimethyl-10-[ (2s,3s,4R)-2,3,4,5 tetrahydroxypentyl]benzo[g]pteridine-2,4-  dione

Physiological Role

            Riboflavin play many roles in variety cellular processes, in the metabolism of carbohydrates, fats and proteins, forming of red cell blood, antibody and also energy release in metabolism process. FAD of flavoproteins is required to convert retinal (vitamin A) to retinoic acid . FMN is the primary coenzyme form of vitamin B₆ (pyridoxal phosphate).

Food source

            We can find riboflavin (vitamin B₂) in some foods, for examples are asparagus, popcorn, bananas, cheese, milk, yogurt, meat, eggs, fish, green beans, leafy green vegetables, liver, tomatoes, yeast, mushrooms and almonds. In daily dietary male 23-50 ages needs 1.6 mg and female needs 1.2 mg. For 50+ ages, male needs 1.4 mg and female needs 1.2 mg.

Effects or Defeciency

            Signs and symptomps of riboflavin deficiency (ariboflavinosis) include cracked and red lips, inflamation of the lining of mouth and tongue, mouth ulcers, cracks at the coroners of the mouth and sore throat, dry and scaling skin, fluid in the mocuous membranes, bloodshot eyes, itchy, watery and sensitive to bright light.

Carnot ( power point)

Carnot cycle
Carnot cycle is a reversible cycle, which was first proposed by Sadi Carnot in 1824.Theoretical machine that uses the Carnot cycle is called a Carnot Heat Engine. Thereversed Carnot cycle is called a Carnot cycle engine that uses inverted and reversedcarnot cycle is called a Carnot refrigeration machine. The purpose of a heat engine is tochange heat into work with the greatest possible efficiency. During the heat transfer in acarnot engine there should be no temperature difference is large enough.
 
Carnot engine and Carnot principle
No real engine operating reversibly. However, the idea of ​​a reversible engine provides a useful standard for assessing the performance of real machines. This picture shows amachine called, Carnot engine, which is especially useful as an ideal model.

Carnot engine consists of four processes,
2 adiabatic process: adiabatic expansion and adiabatic compression.
2 isothermal expansion process isotermik namely with the addition of heat and isothermalcompression with heat release

For the Carnot engine, the comparison between the heat dissipated by the heat input QHQC can be expressed by the following equation:

 

with TC and TH in kelvins (K).

Carnot engine efficiency can be written is as follows:

 

This relationship gives the value of the maximum possible efficiency of a heat engineoperating between the TC and TH


Heat engine KARNOT
Thermal efficiency of all reversible or irreversible heat engine:

 

where
QH is the heat transferred to the heat engine at temperature TH
QL is the heat diteransfer to the heat engine at temperature TL.

The application of Carnot Engine
Application of carnot cycle one found on the motor or combustion engine which is calledthe piston

concept map of diodes(peta konsep dioda)

Thiamine or vitamin B1

Thiamine or thiamin or vitamin B1 named as the “thio-vitamine”(sulfur-containing vitamin”) is a water-soluble vitamin of the B complex. The best-characterized form is thiamine pyrophosphate (TPP), a coenzyme in the catabolism of sugars and amino acids.

There are some Function of thiamin

·  Thiamine is mainly the transport form of the vitamin, while the active forms are phosphorylated thiamine

      derivatives.

·         Thiamine monophosphate

There is no known physiological role of ThMP

·      Thiamine diphosphate

·         ThDP is a coenzyme for several enzymes that catalyze the transfer of two carbon units and in the 

       particular the dehydrogenation of 2-oxoacid.

·         Thiamine triphosphate was long consider a specific neuroactive form of thiamine.

·         Adenosine thiamine triphosphate, it  accumulates  as a result of carbon starvation.

·         Adenosine thiamine diphosphate exsists in small amounts in vertebrate liver, but its role remains unknown.

Source of Thiamine

Complex thiamine biosynthetic pathways occur in bacteria, some protozoan, plants and fungi.

The thiazole and pyrimidine moieties are synthesized separately and then assembled to form ThMP by thiamine phosphate synthase.The biosynthetic pathways are regulated by riboswitches in all organism that synthesise thiamine.

Thiamine is found in a wide variety of foods at low concentration.

·            Yeast extract and pork are the most highly concentrated sources of thiamine.

·            In general, cereal grains are the most important dietary sources of thiamine, by virtue of their ubiquity.

·            Some other foods rich in thiamine are oatmeal, flax, and sunflower seeds, brown rice, whole grain rye,

        asparagus, kale, cauliflower, potatoes, oranges, liver (beef, pork, and chicken), and eggs.

Reference Daily Intake and High Doses

·         The RDA in most countries is set at about 1.4 mg,. However, tests on female volunteers at daily doses of about 50 mg have claimed an increase in mental acuity.

  

Deficiency

·        Thiamine derivates and thiamine-dependent enzymes are present in all cells of the body, thus a thiamine deficiency would seem to adversely affect all of the organ system.

·       However, the nervous system and the heart are particularly sensitive to thiamine deficiency, because of  their high oxidative metabolism.

       Thiamine deficiency can lead to severe fatigue of eyes and myriad problems including neurodegeneration, wasting, and death.

A lack of thiamine can be caused by

·        malnutrition, a diet high in thiaminase-rich foods (raw freshwater fish, raw shellfish, ferns) and/or high in anti-thiamine factors ( tea, coffee, betel nuts)

·       grossly impaired nutritional status associated with chronic diseases, such as alcoholism, gastrointestinal diseases, HIV-AIDS and  persistent vomiting.

Beriberi

·            Beriberi is a neurological and cardiovascular disease.

·            Dry beriberi

·            Wet beriberi

·            Infantile beriberi

Alcoholic Brain Disease

·       Wernicke’s encephalopathy is the most frequently encountered manifestation of thiamine deficiency in Western society

·   Korsakoff Psychosis is  an amnestic-confabulatory syndrome characterized by retrograde and anterograde amnesia, impairment of conceptual functions, and decreased spontaneity and initiative.

Too Much of Thiamine

·            Doses higher than 100 mg may cause drowsiness or muscle relaxation.

·            Large doses (5,000 to 10,000mg) can cause headaches, irritability, rapid pulse, and weakness.

·            Stomach upset

examples of curriculum vitae ( Contoh Riwayat Hidup)

1.       PERSONAL DATA 

          Name: Hery Admin

          Place / Date of birth: Binjai, January 18, 1992

          Gender: male
          Religion: Islam

          Nation: Indonesia

          Educational Background: S-1

          Major: Physics

          Address: No. Jln.Sudirman. field 84

          Telephone: 08527721212


2.       EDUCATION DATA

          1. Medan State 1.SD 027 225 graduates in 2004

          2. SMP Medan District 1 graduates in 2007

          3. SMANegeri a graduate field in 2010

          4. Universitas of Medan until now

          Thus the curriculum vitae of this I do with the actual.


                                                                                     Yours sincerely,




                                                                                        Hary Admin

Temperature

The concept of temperature and the Law to 0
What was the object of investigation in the system is called thermodynamics. Eg gas, liquid, a piece of metal, batteries, and others.

 
Between system and environment are the dividing wall.
We note that between system and environment interactions may occur.
Interaction is the exchange of heat (or thermal interactions) and procurement effort.If thr Interaction prevented from happening, the system is called isolated.


TEMPERATURE
The size of the cold temperature is the heat of an object relative and this is one determinant of physical properties of an object.
Temperature is a measure of the average kinetic energy of molecular motion.
Microscopically, the temperature shows the energy possessed by an object.

LAW TO-0
This law put the concept of temperature on a solid basis, ie when there are two systems in thermal equilibrium, then both have the same temperature, if not in thermal equilibrium then both have different temperatures.

If system A is in thermal balance with the system B and system A is in thermal balance with the system C, then B is a balanced system with a system of C.


Measurement of temperature
Temperature measuring device called a thermometer.
In order to place a quantitative measurement, a thermometer need a scale affixed.
Absolute scale in the SI system is the thermodynamic temperature kelvin (K), the formula dimensions were measured with an ideal gas thermometer.
Another temperature scale (non-SI) are still widely used is the Celsius temperature scale, Fahrenheit, and Reamur.
Each thermometer has its own advantages and disadvantages

Temperature Measurement
1. Water Thermometers Alcohol
If the fluid heats the alcohol will increase so that the scale increases

 


2. Gas thermometers at fixed volume
Termomter gas using the principle of the influence of temperature on pressure.

 


3. Thermocouple Thermometers
Can measure the range - up to 1500o 180o C depending on the type of metal

Scale-Scale Thermometers