Metabolisme bersama

Tujuan metabolisme

1.Mendapatkan energi untuk berbagai aktivitas sel/tubuh

2.Mendapatkan molekul penting penyusun sel / tubuh

Jalur metabolisme utk mendapatkan energi

Metabolisme karbohidrat :•Glikogenolisis •Glikolisis •Oksidasi piruvat

Metabolisme lipida :•Lipolisis •Oksidasi beta asam lemak

Metabolisme asam amino :•Katabolisme asam amino

Jalur metabolisme utk menyimpan energi

Metabolisme karbohidrat :•Glikogenesis glikogen•Glukonegenesis glukosa•Jalur pentosa fosfat NADPH•Pembentukan kreatin fosfat (otot)

Metabolisme lipida :•Lipogenesis asam lemak•Pembentukan gliserida•Ketogenesis

Jalur metabolisme untuk membentuk molekul penting

Metabolisme karbohidrat :•Jalur pentosa fosfat - ribosa P nukleotida •Pembentukan laktosa•Pembentukan asam uronat glikan, molekul konjugat

Metabolisme lipida :•Pembentukan kholesterol steroid, membran sel•Pembentukan fosfolipida membran sel

Metabolisme asam amino :•Pembentukan protein•Pembentukan produk khusus : kreatin, melanin, adrenalin, tiroksin, hem, purin, pirimidin, melatonin, histamin, NO

KaKatabolisme zat gizitabolisme zat gizi untuk untuk mendapatkan energimendapatkan energi

Summary of Summary of glycolysisglycolysis

blocked by anaerobic conditions or by absence of mitochondria containing key respiratory enzymes, eg, as in erythrocytes.

Catabolism of Catabolism of dietary dietary

carbohydrate, carbohydrate, protein, and fat.protein, and fat.

All the pathways lead to the production of acetyl-CoA, which is oxidized in the citric acid cycle, ultimately yielding ATP in the process of oxidative phosphorylation

Hubungan antara jalur katabolisme dan jalur anabolisme dalam metabolisme.

Energi kimia dalam molekul makanan dikeluarkan dengan proses katabolisme, menghasilkan molekul sampah dan molekul kecil satuan penyusun.

Molekul penyusun tubuh penyusun tubuh dibentuk dari molekul kecil melalui proses anabolisme.

Molekul–molekul makanan Molekul –molekul

penyusun tubuh

Molekul kecil satuan penyusun

katabolisme anabolismeenergi

Molekul sampah

Pertukaran energi dan peran molekul pengangkut energi dalam metabolisme

Molekul makanan dipecah (catabolisme) untuk menghasilkan energi .

Energi digunakan untuk pembentukan molekul besar penyusun sel. (anabolisme).

Energi juga diperlukan untuk pergerakan sel dll.

Beberapa jenis molekul pembawa energi dalam Metabolisme

Molekul pembawa Gugus kimia dengan ikatan berenergi tinggi

ATP fosfat

NADH, NADPH, FADH2 elektron dan hidrogen

Asetil-koA Gugus asetil

Biotin terkarboksilasi Gugus karboksil

S-Adenosilmetionin Gugus metil

Uridin difosfat glukosa Glukosa

Katabolisme zat makanan

Pencernaan makanan Metabolisme zat makanan Produksi energi

2H : NADHFADH2

Ekstra mitokhondria

Tahap akhir katabolisme zat makanan

Molekul pemindah energi :ATPNADHAsetil-koA

Molekul ampas :C02

H20

Siklus Kreb’s = siklus asam sitrat = siklus asam trikarboksilat

Acyl-coA Fatty acidpyruvateglucose

Bahan : Asetil-koA

Hasil :

•2CO2,

•H (NADH, FADH2)

•GTP ~ ATP

the chemiosmotic theory of oxidative the chemiosmotic theory of oxidative phosphorylationphosphorylation

Enzymes in chemiosmotic synthesis

. Enzymes in chemiosmotic synthesis arranged in an electron transport chain that is embedded in a membrane

Electron tranport

A generalized view of an electron transport system

.

Flow electrons during Ox_Phosph

ATP = Adenosin Trifosfat

Molekul dlm sel yg dpt menghasilkan energi scr cpt untuk digunakan oleh sel-sel tubuh•Energi kimia dari putusnya ikatan fosfat ke 3 menghasilkan ADP dan P anorganik•Energi yang lepas dapat digunakan oleh sel untuk bergerak atau anabolisme

PA P P

Bongkar muat energi dalam molekul ATP

energi

Fungsi ATP

1. berperan pada reaksi sintesis molekul besar

2. Transport aktif material melintasi membran sel

3. Berperan pada Kontraksi otot-otot

Overview of amino acid metabolismOverview of amino acid metabolism

Citric acid cycle in transamination and gluconeogenesisCitric acid cycle in transamination and gluconeogenesis

The bold arrows indicate the main pathway of gluconeogenesis

The provision of acetyl-CoA and NADPH for lipogenesis. The provision of acetyl-CoA and NADPH for lipogenesis.

(PPP, pentose phosphate pathway; T, tricarboxylate transporter; K, α-ketoglutarate transporter; P, pyruvate transporter.)

Participation of the citric acid cycle in fatty acid Participation of the citric acid cycle in fatty acid synthesis from glucosesynthesis from glucose

Biosynthesis of Biosynthesis of long-chain fatty acids. long-chain fatty acids.

Redox reactions of glutathioneRedox reactions of glutathione

(G-S-S-G, oxidized glutathione; G-SH, reduced glutathione; Se, selenium cofactor.)

Role of the pentose phosphate pathway in the glutathione peroxidase reaction of erythrocytes.

Conversion of galactose to glucoseConversion of galactose to glucose

Pathway of conversion of galactose to glucose in the liver

Conversion of glucose to lactoseConversion of glucose to lactose

Pathway of conversion of glucose to lactose in the lactating mammary gland.

Transport and fate of major carbohydrate and Transport and fate of major carbohydrate and amino acid substrates and metabolites. amino acid substrates and metabolites.

Note that there is little free glucose in muscle, since it is rapidly phosphorylated upon entry.

Fructose & Sorbitol in the Lens AreFructose & Sorbitol in the Lens AreAssociated With Diabetic CataractAssociated With Diabetic Cataract

Both fructose and sorbitol are found in the lens of the eye in increased concentrations in diabetes mellitus and may be involved in the pathogenesis of diabetic cataract.

The sorbitol (polyol) pathway (not found in liver) is responsible for fructose formation from glucose increases in activity as the glucose concentration rises in diabetes in the lens, peripheral nerves, and renal glomeruli not insulin-

sensitive)

Glucose is reduced to sorbitol by aldose reductase, followed by oxidation of sorbitol to fructose in the presence of NAD+ and sorbitol dehydrogenase (polyol dehydrogenase).

Fructose & Sorbitol in the Lens AreAssociated With Diabetic Cataract

Sorbitol does not diffuse through cell membranes easily and accumulates, causing osmotic damage. Simultaneously, myoinositol levels fall.

Sorbitol accumulation, myoinositol depletion, and diabetic cataract can be prevented by aldose reductase inhibitors in diabetic rats, and promising results have been obtained in clinical trials.

When sorbitol is administered intravenously, it is converted to fructose rather than to glucose.

Sorbitol is poorly absorbed in the small intestine, and much is fermented by colonic bacteria to short-chain fatty acids, CO2, and H2, leading to abdominal pain and diarrhea (sorbitol intolerance).

Peran jaringan/organ

1. Hepar 2. Otot 3. Jantung 4. Usus 5. Ginjal 6. Adiposa 7. Otak/syaraf 8. Epitel

MajorMajor metabolic metabolic pathwayspathways

Intracellular location and overview of major metabolic pathways in a liver parenchymal cell.

(AA →, metabolism of one or more essential amino acids; AA ↔, metabolism of one or more nonessential amino acids.)