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
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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
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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 nonkovalen (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 Water
Water 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 welldefined 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?
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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.
2.
3.
4.
Struktur air (sifat-sifat kimia dan fisik) – the structure of water
Fungsi air (dalam tubuh) – the function of water for body
Air sebagai pelarut (solvent) – Water as universal solvent
Struktur dan fungsi air hujan (rain water) untuk minum –
Rainwater for drinking water
5. Kemungkinan air tanah (ground water) untuk minum –
Groundwater for drinking water
6. Air yang mengandung mikroorganisme untuk air minum –
Micoorganism Contaminated water for drinking water
7. Air yang mengandung bahan tidak larut (insolouble materials)
untuk minum – insolouble substanses containing water for
drinking water
8. Ionized water: apakah penting?
9. Air minum yang sehat dan menyehatkan (macam-macam air
minum) – Healthy drinking water
10. Air penstabil dalam makromolekul
Kriteria format:
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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. ............ NIM
2. ...........NIM
3. ..........NIM, dst.
FAKULTAS PETERNAKAN
UNIVERSITAS BRAWIJAYA
2012
Format isi
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Kata pengantar
Daftar isi
Daftar gambar
Daftar tabel (bila ada)
Pendahuluan
• Isi tulisan
• Daftar pustaka