WATER:Structure and Function

Prof. Dr.sc.agr. Ir. Suyadi, MS.

What’s water?

• Water (H2O) is the most abundant compound on Earth's surface, covering about 70 percent of the planet.

• In nature, water exists in liquid, solid, and gaseous states.

• It is in dynamic equilibrium between the liquid and gas states at standard temperature and pressure.

• At room temperature, it is a tasteless and odorless liquid, nearly colorless with a hint of blue.

Other names of water• Water, Oxidane, Hydrogen oxide• Dihydrogen monoxide (DHMO)• Hydrogen monoxide• Dihydrogen oxide• Hydrogen hydroxide (HH or HOH)• Hydric acid• Hydrohydroxic acid• Hydroxic acid• Hydroxylic acid• Hydroxilic acid• Hydrol• μ-Oxido dihydrogen

Water and organism

• All organism contain water• Water is major component in living organism• In the body, water >60%• Water usually makes up 55% to 78% of the

human body.

Water in our body• About two-thirds of the weight of an adult human consists of

water. • About two-thirds of this water is located within cells, while the

remaining third consists of extracellular water, mostly in the blood plasma and in the interstitial fluid that bathes the cells.

• This water, amounting to about five percent of body weight (about 5 L in the adult), serves as a supporting fluid for the blood cells and acts as a means of transporting chemicals between cells and the external environment.

• It is basically a 0.15M solution of salt (NaCl) containing smaller amounts of other electrolytes, the most important of which are bicarbonate (HCO3

–) and protein anions.

Water (H2O): molecule structure

• Air memiliki struktur tiga dimensi tetrahedron tidak beraturan dengan oksigen sebagai pusatnya

• Dua buah ikatan dg hidrogen diarahkan ke dua sudut tetrahedron, sementara elektron-elektron yang tidak dipakai bersama pada kedua orbital terhidrasi menempati dua sudut sisanya

Molekul air membentuk molekul bipolar

• Karena bentuknya tetrahedron yang miring, maka muatan listrik tidak menyebar merata.

• Sisi oksigen yang berlawanan dengan hidrogen memiliki muatan listrik lebih tinggi (lebih banyak mengandung elektron) daripada hidrogen yang terpencar.

• Bipolar muatan listrik (elektron) tidak merata.

Air menstabilkan molekul biologik

• Sebagian besar molekul memiliki ikatan kovalen antar elemen (unsur) dengan energi 30 – 150 kkal/mol

• Air memiliki kemampuan menjembatai molekul lain dengan membentuk ikatan non-kovalen (ikatan hidrogen) 0,1 – 10 kkal/mol menstabilkan suatu makromolekul

IKATAN HIDROGEN DARI AIR• Ikatan hidrogen menentukan struktur

makromolekul– Air yang cair dan es, membentuk

makromolekul melalui ikatan bipolar mengikat dirinya sendiri dalam keadaan padat dan cair

– Interaksi elektrostatik antara atom hidrogen satu molekul air bipolar denan pasangan elektron yang tidak dipakai-bersama pada molekul air bipolar lain akan membentuk sebuah ikatan hidrogen.

Ikatan hidrogen dari air• Ikatan hidrogen

menstabilkan protein dan asam nukleat– Sifat bipolar air

menyebabkan kemampuannya berikatan dg beberapa senyawa spt –OH, --SH, amina, ester, aldehid, keton

– Makromolekul spt protein distabilkan oleh ikatan hidrogen intramolekul

The present of water

• Water (H2O) is the most abundant compound on Earth's surface, covering about 70 percent of the planet

• At room temperature, it is a tasteless and odorless liquid, nearly colorless with a hint of blue.

Characteristics of water

• Many substances dissolve in water and it is commonly referred to as the universal solvent. Because of this, water in nature and in use is rarely pure and some of its properties may vary slightly from those of the pure substance.

• There are also many compounds that are essentially, if not completely, insoluble in water.

Forms of WaterWater can take numerous forms that are broadly categorized by phase of

matter:1. The liquid phase is the most common among water's phases (within

the Earth's atmosphere and surface) and is the form that is generally denoted by the word "water."

2. The solid phase of water is known as ice and commonly takes the structure of hard, amalgamated crystals, such as ice cubes, or loosely accumulated granular crystals, like snow. For a list of the many different crystalline and amorphous forms of solid H2O, see the article ice.

3. The gaseous phase of water is known as water vapor (or steam), and is characterized by water assuming the configuration of a transparent cloud.

Liquid and solid water• Ice, like all solids, has a well-

defined structure; each water molecule is surrounded by four neighboring H2Os. two of these are hydrogen-bonded to the oxygen atom on the central H2O molecule, and each of the two hydrogen atoms is similarly bonded to another neighboring H2O

Here are three-dimensional views of a typical local structure of water (left) and ice (right.)

Physics and chemistry

• Water is the chemical substance with chemical formula H2O: one molecule of water has two hydrogen atoms covalently bonded to a single oxygen atom.

• Water is a tasteless, odorless liquid at ambient temperature and pressure, and appears colorless in small quantities, although it has its own intrinsic very light blue hue

Chemistry

• The molecules of water are constantly moving in relation to each other, and the hydrogen bonds are continually breaking and reforming at timescales faster than 200 femtoseconds

• Water can be described as a polar liquid that slightly dissociates disproportionately into the hydronium ion (H3O+(aq)) and an associated hydroxide ion (OH−(aq)).2 H2O (l) H3O+ (aq) + OH− (aq)

Water in redox reactions

• Water contains hydrogen in oxidation state +1 and oxygen in oxidation state −2. Because of that, water oxidizes chemicals with reduction potential below the potential of H+/H2, such as hydrides, alkali and alkaline earth metals

2 Na + 2 H2O → 2 NaOH + H2

"Pure" water

• To a chemist, the term "pure" has meaning only in the context of a particular application or process. The distilled or de-ionized water used in the laboratory contains dissolved atmospheric gases and occasionally some silica, but their small amounts and relative inertness make these impurities insignificant for most purposes.

Drinking Water• Our ordinary drinking water, by contrast, is never

chemically pure, especially if it has been in contact with sediments.

• Groundwaters (from springs or wells) always contain ions of calcium and magnesium, and often iron and manganese as well; the positive charges of these ions are balanced by the negative ions carbonate/ bicarbonate, and occasionally some chloride and sulfate.

• Groundwaters in some regions contain unacceptably high concentrations of naturally-occuring toxic elements such as selenium and arsenic.

What kind of water is most healthy to drink?

• No toxic• No heavy metal• No patogenic microorganism• No non-solouble subtances (like pesticide)• pH 5 - 9

How is with ionized water?• Ionized water actually isn't as

mysterious as it may sound. Ionized water is the result of a water source (usually tap water) being exposed to electrolysis using water ionizers.

• The resulting reduced water is flush with a large amount of electrons which can, in theory, be "donated" to active oxygen so that it may aid in the fight of free radicals in the human body.

• This "reduced water" is also known as alkaline ionized water.

Tugas untuk Tema Kuliah water..1. Struktur air (sifat-sifat kimia dan fisik) – the structure of water2. Fungsi air (dalam tubuh) – the function of water for body3. Air sebagai pelarut (solvent) – Water as universal solvent4. Struktur dan fungsi air hujan (rain water) untuk minum – Rainwater for

drinking water5. Kemungkinan air tanah (ground water) untuk minum – Groundwater for

drinking water6. Air yang mengandung mikroorganisme untuk air minum – Micoorganism

Contaminated water for drinking water7. Air yang mengandung bahan tidak larut (insolouble materials) untuk

minum – insolouble substanses containing water for drinking water8. Ionized water: apakah penting?9. Air minum yang sehat dan menyehatkan (macam-macam air minum) –

Healthy drinking water10. Air penstabil dalam makromolekul

Kriteria format:

• Bentuk Paper kelompok• Diketik dalam ukuran A4 (21 x 29 cm)• Huruf Arial, font 11, 1 spasi• Jumlah halaman minimal 10 (pendahuluan + isi) • Menggunakan Bahasa Indonesia baku• Harus menggunakan pustaka minimal 5 buah.• Dikumpulkan 2 minggu dari sekarang dalam bentuk:

– file dikirim suyadi@ub.ac.id (nama file/ subjek “tugas biokimia Kelas.... kel....”

– hard copy dikumpulkan melalui ketua kelas

Format halaman depan

TUGAS BIOKIMIA KE...Kelas.... Kelompok....

Judul: .......... ........................................... ........Dosen Pembina: Prof. Dr.sc.agr. Ir. Suyadi, MS.

Simbul UB

Anggota Kelompok:1. ............ NIM2. ...........NIM

3. ..........NIM, dst.

FAKULTAS PETERNAKANUNIVERSITAS BRAWIJAYA

2012

Format isi

• Kata pengantar• Daftar isi• Daftar gambar• Daftar tabel (bila ada)• Pendahuluan• Isi tulisan• Daftar pustaka