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Metabolism

Carbohydrates

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Glucose metabolism

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glycogenolysis

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glycolysis

Glucose→2 Pyruvate

產生： 2 ATP, 2 NADH + 2H+

Glucose→2 Lactate

產生： 2 ATP

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Krebs cycle

Glucose→2 Acetyl CoA→TCA cycle

產生 24 ATP

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Glucose aerobic metabolism

1 Glucose→2 pyruvate (2ATP)

→ Bisphosphoglycerate cycle (4~6 ATP)

→2 Acetyl CoA (6 ATP)

→TCA cycle (24 ATP)

產生 36~38 個 ATP

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Triacylglycerol digestion

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Triacylglycerol digestion膳食脂肪

↓胃脂解酶 (水解乳糜化脂肪 )，十二指腸中 (CCK刺激膽汁分泌 )。

乳糜化脂肪

↓胰脂解酶，腸脂解酶

FFA, monoacylglycerol, diacylglycerol

↓bile salt

Micelle ( 含 FFA, monoacylglycerol, diacylglycerol)

↓在小腸黏膜吸收 (小於十二碳的脂肪酸進入門靜脈循環 )

再合成 triacylglycerol

↓apoprotein, phospholipid, cholesterol, FFA, TG混合

乳糜微粒 (chylomicron)

↓

淋巴或血液循環

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Lumen of small intestine

Triacylglycerol

Phospholipid

Cholesterol

Glycerol

3 fatty acids

2-monoacylglycerol or

2 fatty acids

Bile from liver

Micelle

Fatty acids

2-monoacylglycerol

Enterocyte

Lymphatic system lacteal

Blood capillary

Chylomicron

PhospholipidsCholesterol

Protein

Triacylglycerol synthesis

+

+

Pancreaticlipase

Fig. 2-15, p. 43

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1. LPL：脂蛋白脂解酶 (lipoprotein lipase)，水解脂蛋白上之三酸甘油脂。

2. LCAT：卵磷脂 -膽固醇醯基轉移酶(Lecithin-Cholesterol acyltransferase)，可促進游離膽固醇代謝成膽固醇酯。

Important Enzymes

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Lipoprotein metabolismChylomicron

↓經過微血管與細胞間，受 LPL 將 TG分解成甘油 &FFA 。

Chylomicron remnant

↓apoE可讓 liver辨識這些殘餘物，而送至肝中代謝。

VLDL

↓內含的 TG稱為內生性三酸甘油酯，與 chylomicro中外生性 TG不同

IDL ( 含 FFA, monoacylglycerol, diacylglycerol)

↓進入肝臟，再變成 VLDL ↓變成 LDL，再進入肝臟代謝。

↑

HDL 膽固醇清道夫，將細胞或組織中的膽固醇帶入肝臟。

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Metabolism of FA

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Metabolism of FA種類 產物 重要性 定義

β-oxidation Acetyl CoA 大 由 COOH端開始行氧化作用，每次移去二個碳原子，但不產生 CO2，目的在產能。

α-oxidation Fatty acid orFatty alcohol

小 由 COOH端開始行氧化作用，每次移去一個碳原子，可移去 CO2 。

ω-oxidation α,ω-dicarboxylic acid

小 將 ω-碳原子氧化為ω- COOH，但不移去碳原子。

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脂質合成分類 說明 意義

粒線體內 將 Acetyl CoA接到已經合成好的脂肪酸上

合成 fatty acyl CoA

細胞質 利用malonyl CoA為組成單位，每次增加二個碳，形成一定長度的FA

脂肪酸重新合成的主要所在

微粒體內 將 malonyl CoA之二個碳接到已經合成好的FA

為脂肪酸碳鏈延長的主要場所

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Metabolism

Protein

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