biomolekul & ikatan kimia(1)

BIOMOLEKUL(Dr. I Dewa Ayu Susilawati, drg. M. Kes)

Setelah mempelajari bab ini, anda diharapkan mampu:

1.Menjelaskan jenis, struktur, sifat & fungsi biomolekul yang menyusun tubuh manusia

2.Menjelaskan jenis & sifat ikatan kimia pada biomolekul

BIOMOLEKUL(Molekul Kehidupan)

Kehidupan: hasil kumulatif dari interaksi senyawa-senyawa kimia yg menyusun sel-sel suatu organisme hidup

Organisme hidup bila diuraikan, terdiri dari senyawa-senyawa kimia = biomolekul

Biomolekul = senyawa penyusun kehidupan

AtomMolekul terdiri dari atom/unsur* Atom: unit terkecil materi

Terdiri dari:inti: neutron (tidak bermuatan) &

proton (bermuatan positif)kulit : orbit elektron (bermuatan negatif)

* Unsur: substansi mengandung satu jenis atom

STRUKTUR ATOM

UNSUR-UNSUR YANG MENYUSUN TUBUH MANUSIA

SIMBOL UNSUR NOMER ATOM PERSEN BERAT

OCHNCaPKSNaClMg

OksigenKarbonHidrogenNitrogenKalsiumFosforKaliumSulfurNatriumKlorinMagnesium

8617

20151916111712

65,018,59,53.31,51,00,40,30,20,20,1

Unsur –unsur kelumit (kurang dari 0,01%): Boron (B), Kromium (Cr), Kobalt (Co), Tembaga (Kuprum, Cu), Fluorin (F), Iodin (I), Besi (Fe), Mangaan (Mg), Molibdenum (Mo), Selenium (Se), Silikon (Si), Timah (Sn), Vanadium (V) dan Seng (Zn)

Reaksi antar atom Ikatan Kimia

* Adalah tarik menarik antara atom atau molekul yg memungkinkannya membentuk senyawa kimia.* Tarik menarik disebabkan oleh:

- Kekuatan elektromagnetik- Muatan berlawanan- Neklei-elektron- Kutub-kutub (dipole-dipole)

* Kekuatan ikatan- Ikatan kuat: ikatan kovalen,

ikatan ion- Ikatan Lemah : interaksi dipole,

ikatan hidrogen, ikatan Van Der Waals

Ikatan ion

Ikatan kovalenAtom membentuk molekul dg cara berbagi elektron

Ikatan kovalen non polar* Atom-atom yg membentuk ikatan kovalen berbagi elektron secara merata karena memiliki keelektronegatifan sama atau hampir sama* Keelektronegatifan: kemampuan inti atom untuk menarik elektronnya* Misal ikatan C-C; C-H; H-H

Ikatan kovalen polar* Jika salah satu atom lebih elektronegatif, elektron tidak terbagi secara merata, tetapi lbh tertarik ke salah satu inti atom kutub-kutub (δ+ atau δ-)* Contoh: C-O; C-N; O-H; N-H

van der Waals forces: dipole-dipole interactions

Ikatan Hidrogen

Ikatan hidrogen pada molekul Air

Makromolekul= polimer* Polimer karena tersusun oleh banyak

atom, maka BM nya besar > 100.000 dalton makromolekul

* Empat kelompok biomolekul utama: masing-masing mempunyai monomer karakteristik

Monomer Polimer

Asam lemak Diasilgliserol, triasilgliserol

Monosakarida polisakarida

Asam amino Polipeptida, protein

nukleotida Polinukleotida (RNA, DNA)

PROTEIN

FUNCTION AND

STRUCTURE

Protein function in humans (dynamic & structural function)

1. Enzymatic catalysis2. Transport & storage e.g. transferrin, ferritin, hemoglobin, etc3. Coordination motion, contractile e.g. actin, myosin, etc4. Mechanical support, structural proteins e.g. collagen, elastin, etc5. Immune response e.g. immunoglobulin, interferon, complements, cytokines,

etc6. Hormones e.g. insulin, somatotropin, thyrotropin, etc7. Receptors8. Control gen transcription & regulation e.g histone, NFkB, robosomal protein, etc

• Protein proteos the firstPlay crucial roles in virtually all biological processes

• Proteins are organic compounds made of amino acids (polymers of α-amino acids)

• Kinds of amino acids: 20

• Amount of amino acids > 50

AMINO ACIDS• Amino acids are molecules containing an

amine group, a carboxylic acid group and one of the twenty R-groups.

• The amino acids in a polymer chain are joined together by the peptide bonds between the carboxyl and amino groups of adjacent amino acid residues

Peptide bondA peptide bond is a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, thereby releasing a molecule of water (H2O).

One-lettersymbol

Three-lettersymbol Amino acid

A Ala alanine

B Asx aspartic acid or asparagine

C Cys cysteine

D Asp aspartic acid

E Glu glutamic acid

F Phe phenylalanine

G Gly glycine

H His histidine

I Ile isoleucine

K Lys lysine

L Leu leucine

M Met methionine

N Asn asparagine

P Pro proline

Q Gln glutamine

R Arg arginine

S Ser serine

T Thr threonine

U* Sec selenocysteine

V Val valine

W Trp tryptophan

X** Xaa unknown or 'other' amino acid

Y Tyr tyrosine

Z Glx glutamic acid or glutamine

Amino acidssymbol

• Ser-Thr : dipeptide• Asp-Glu-Phe : threepeptide• Phe-Gly-His-Thr : tetrapeptide• < 10 aa : olygopeptide• < 50 aa : polypeptide• > 50 aa : protein

Essential Nonessential

Isoleucine Alanine

Leucine Asparagine

Lysine Aspartic Acid

Methionine Cysteine*

Phenylalanine Glutamic Acid

Threonine Glutamine*

Tryptophan Glycine*

Valine Proline*

Serine*

Tyrosine*

Arginine*

Histidine

Essential amino acids :human body cannot synthesize themfrom other compounds,so they must be obtained from food

Protein Structure Hierarchy

N terminal

C terminal

Tertiary structure

A hemoglobin molecule consists of four polypeptide chains Each of the globins is folded

into a secondary and tertiary structure. Then, all four are put together

into the hemoglobin molecule's quaternary structure

Quaternary structure

L I P I D

STRUCTURE AND

FUNCTION

Adalah kelompok senyawa organik berlemak atau berminyak yang tidak larut dalam air, dapat diekstrak dari sel atau jaringan dengan pelarut non polar seperti kloroform atau eter.

L I P I D

Penyebab tidak larut dlm air karena rantai hidrokarbon alifatik panjang atau cincin benzena yang bersifat non polar.

Jenis lipid utama manusia: asam lemak, trigliserid (triasil gliserol), fosfolipid, kolesterol, kolesterol ester

• Lipids are a broad group of naturally occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The main biological functions of lipids include energy storage, as structural components of cell membranes, and as important signaling

Macam-macam lipid

* Penyusun utama lipid: asam lemak* Asam lemak: asam karboksilat C > 4

Asam Karboksilat Asam Lemak : fatty acids

Asam Lemak Jenuh (saturated): tak ada ikatan rangkap

Asam lemak tak jenuh (unsaturated): ada ikatan rangkap

Trigliserid (Triasilgliserol): TG

Struktur dasar TG :1 gliserol + 3 asam lemak

TG : lipid utama untuk sumber energi

TG : ester dari gliserol dg 3 asam lemak

fosfolipid

Fosfolipid tdr :- Gliserol- asam lemak- Senyawa fosfat

Phospholipid:phosphatidylcholin

Phospholipid:Phosphatidylinositol (PI)

Phospholipid:phosphatidylserin

Phospholipid cell membrane

Phospholipid pada lipoprotein plasma

KOLESTEROL

Kolesterol:- membran- vitamin D- hormon streroid

A nucleotide is composed of a nucleobase (nitrogenous base), a five-carbon sugar, and one to three phosphate groups

NUKLEOTIDA

NUCLEOTIDE * make up the structural units of RNA and DNA* play central roles in metabolism, they serve as

sources of chemical energy: adenosine triphosphate (ATP) and guanosine triphosphate (GTP),

* participate in cellular signaling: cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP),

* cofactors of enzymatic reactions: coenzyme A (CoA), flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), and nicotinamide adenine dinucleotide phosphate (NADP)

polinukleotida

• MononucletideATP, GTP, ADP, AMP, dll

• DinucleotideFAD, NAD

• PolynucleotideDNA, RNA

KARBOHIDRAT

- Carbohydrates consist (CH2O)n

-Carbohydrates include sugars, starches,

cellulose and many other compounds found in

living organisms.

-simple sugars or monosaccharides.

-combination of two simple sugars: disaccharide.

-Carbohydrates consisting of two to ten simple

sugars are called oligosaccharides,

- larger number are called polysaccharides.

Number ofCarbons Category Name Examples

4 Tetrose Erythrose, Threose

5 Pentose Arabinose, Ribose, Ribulose, Xylose, Xylulose, Lyxose

6 Hexose

Allose, Altrose, Fructose, Galactose, Glucose, Gulose, Idose, Mannose, Sorbose, Talose, Tagatose

7 Heptose Sedoheptulose, Mannoheptulose

Monosaccharide classifications based on the number of carbons

Disaccharide descriptions and components

Sugar Alcohols, Amino Sugars, and Uronic Acids

Glucitol or Sorbitol (a sugar alcohol)

Glucuronic acid (a uronic acid)

Glucosamine (an amino sugar)

Polysaccharides are polymers of simple sugars

Many polysaccharides, unlike sugars, are insoluble in water. Dietary fiber includes

polysaccharides and oligosaccharides that are resistant to digestion and absorption in the

human small intestine but which are completely or partially fermented by microorganisms in the large intestine.

Amylose molecules consist typically of 200 to 20,000 glucose units which form a helix as a result of the bond angles between the glucose units

GlycogenGlucose is stored as glycogen in animal tissues by the process of glycogenesis. When glucose cannot be stored as glycogen or used immediately for energy, it is converted to fat. Glycogen is a polymer of α-D-Glucose. The glucose chains are organized globularly like branches of a tree originating from a pair of molecules of glycogenin, a protein with a molecular weight of 38,000 that acts as a primer at the core of the structure. Glycogen is easily converted back to glucose to provide energy.

homework

• 1. Bagaimanakan struktur Monoasilgliserol, diasilgliserol?

• 2. Bagaimanakah struktur ATP, ADP, AMP?• 3. Bagaimanakah struktur ester kolesterol