Water

Water (from the Old English word wæter; c.f German "Wasser", Danish "Vand", Russian вода [voda]) is a tasteless, odorless, and nearly colorless (it has a slight hint of blue) substance in its pure form that is essential to all known forms of life and is known also as the most universal solvent.

Water is an abundant substance on Earth. It exists in many places and forms: mostly in the oceans and polar ice caps, but also as clouds, rain water, rivers, freshwater aquifers, and sea ice. On the planet, water is continuously moving through the cycle involving evaporation, precipitation, and runoff to the sea.

Water that humans consume is called potable water. This natural resource is becoming more scarce in certain places as human population in those places increases, and its availability is a major social and economic concern.

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Nucleic acid

A nucleic acid is a complex, high-molecular-weight biochemical macromolecule composed of nucleotide chains that convey genetic information. The most common nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Nucleic acids are found in all living cells and viruses.

Schematic diagram of a double-stranded nucleic acid. Yellow-green shaded circles represent phosphate; green-hatched circles represent pentose; red-slashed circles represent nitrogenous bases. Solid lines represent covalent bonds; dotted lines represent hydrogen bonds.

Nucleic acid, so called because of its prevalence in cellular nuclei, is the generic name of family of biopolymers. The monomers are called nucleotides, and each consists of three components: a nitrogenous heterocyclic base (either a purine or a pyrimidine), a pentose sugar, and a phosphate group. Different nucleic acid types differ in the specific sugar found in their chain (e.g. DNA or deoxyribonucleic acid contains 2-deoxyriboses). Also, the nitrogenous bases possible in the two nucleic acids are different: adenine, cytosine, and guanine are possible in both RNA and DNA, while thymine is possible only in DNA and uracil is possible only in RNA...

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Biochemistry

                Biochemistry is the chemistry of life, a bridge between biology and chemistry that studies how complex chemical reactions give rise to life. It is a hybrid branch of chemistry which specialises in the chemical processes in living organisms. This article only discusses terrestrial biochemistry (carbon- and water-based), as all the life forms we know are on Earth. Since life forms alive today are believed to have descended from the same common ancestor, they naturally have similar biochemistries, even for matters which would appear to be essentially arbitrary, such as the genetic code or handedness of various biomolecules. It is unknown whether alternate biochemistries are possible or practical.

                Biochemistry is the study of the structure and function of cellular components, such as proteins, carbohydrates, lipids, nucleic acids, and other biomolecules.

Although there is a vast number of different biomolecules, they tend to be composed of the same repeating subunits (called monomers), in different orders. Each class of biomolecules has a different set of subunits. Recently, biochemistry has focused more specifically on the chemistry of enzyme-catalyzed reactions, and on the properties of proteins.

                The biochemistry of cell metabolism and the endocrine system has been extensively described. Other areas of biochemistry include the genetic code (DNA, RNA), protein synthesis, cell membrane transport, and signal transduction...

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Biosintesis Protein

melibatkan proses translasi
merupakan proses yang mengubah informasi genetic yang terdapat pada mRNA menjadi polipeptida dengan urutan asam amino tertentu....



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Enzyme

         An enzyme (from Greek énsimo (ένζυμο), formed by én = at or in and simo = leaven or yeast) is a protein that catalyzes, or speeds up, a chemical reaction. Enzymes are essential to sustain life, because most chemical reactions in biological cells would occur too slowly or would lead to different products without enzymes. A malfunction (mutation, overproduction, underproduction or deletion) of a single critical enzyme can lead to severe diseases. For example, phenylketonuria is caused by an enzyme malfunction in the enzyme phenylalanine hydroxylase, which catalyses the first step in the degradation of phenylalanine. If this enzyme does not function, the resulting build-up of phenylalanine leads to mental retardation.

       Like all catalysts, enzymes work by lowering the activation energy of a reaction, thus allowing the reaction to proceed much faster. Enzymes may speed up reactions by a factor of many thousands. An enzyme, like any catalyst, remains unaltered by the completed reaction and can therefore continue to function. Because enzymes, like all catalysts, do not affect the relative energy between the products and reagents, they do not affect equilibrium of a reaction. However, the advantage of enzymes compared to most other catalysts is their sterio-, regio- and chemoselectivity and specificity...

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Asam Amino dan Protein

Protein

Molekul yg sangat vital untuk organisme à terdapt di semua sel

Polimer à disusun oleh 20 mcm asam amino standar

Rantai asam amino dihubungkan dg iktn kovalen yg spesifik

Struktur & fungsi ditentukan oleh kombinasi, jumlah dan urutan asam amino

Sifat fisik dan kimiawi-> dipengaruhi oleh asam amino penyusunnya

Fungsi Protein 
 

Reaksi kimia ->enzymes

Immune system -> antibodies

Mechanical structure-> tendons

Generation of force -> muscles

Nerve conduction -> ion channels

Vision -> eye lens

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Karbohidrat

• Biomolekul yang paling banyak ditemukan di alam
• Dari namanya à molekul yang terdiri dari carbon (C) dan hydrate (air à H2O)
• Mempunyai rumus molekul (CH2O)n untuk monosakarida
• Disintesis dari CO2 dan H2O dlm proses fotosintesis
• Dikenal juga sebagai sakarida

Berdasar kompleksitasnya, dapat dibagi menjadi 3 golongan

Monosakarida àkarbohidrat tunggal

Oligosakarida à karbohidrat yg tersusun dr bbrp monosakarida

Polisakarida àkarbohidrat yang tersusun dr lebih dari 10 monosakarida

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GLIKOKONJUGAT : Proteoglycan, Glycoprotein, dan Glycolipid

Konjugat Karbohidrat/ Glikokonjugat

PROTEOGLIKAN, GLIKOPROTEIN dan GLIKOLIPID memiliki Fungsi-fungsi biologi yang biologi spesifik, antara lain :

1. Pembawa informasi-> polisakarida dan oligosakarida
2. Sebagai penanda yang dituju oleh beberapa protein
3. Mediator interaksi sel satu dengan yang lain secara spesifik
4. Membentuk matrik sekstraseluler

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Enzim

-Definisi umum

-Bagian penting dari enzim

-Bagaimana enzim bekerja

-Hubungan enzim dng substrat

-Hubungan enzim dng inhibitor

-Faktor-faktor yang mempengaruhi kerja enzim

-Kinetika enzim

Dalam system biologi à reaksi kimia selalu memerlukan katalis.
Tanpa katalis ->sangat lama shgdiperlukan -> Enzim yg berfungsi sbg biokatalisator. Protein yang berfungsi untuk mempercepat reaksi dengan jalan menurunkan tenaga aktivasi dan tidak mengubah kesetimbangan reaksi, serta bersifat sangat spesifik...

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