1.10 Metabolism of fructose and galactose Flashcards
Synthesis of fructose is called…
Fructogenesis
Give the steps of fructogenesis
- Glucose
- Sorbitol
- Fructose
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- Aldose reductase
- NADH + H+ → NAD+
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- Sorbitol dehydrogenase
- NAD+ → NADH + H+
Draw fructogenesis
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Draw fructolysis in humans
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Draw fructolysis in animals
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Fructogenesis occurs in which location(s)?
- Placenta of ungulates
- Seminal vesicle
Cytoplasm
Give the types of fructolysis
- Endogenous
- Placenta of un.
- Seminal vesicle
- Exogenous
- Sucrose → Fructose + glucose
Give the steps of fructolysis (Oxidised in animals)
- Fructose
- Fructose-1-phosphate
- Glyceraldehyde
- Glycerate
- Glycerate-2-phosphate
- GL/GNG
Fructolysis occurs in which location(s)?
Liver cytoplasm
Absorption into the liver via GLUT-5
Give the steps of fructolysis (Reduced in humans)
- Fructose
- Fructose-1-phosphate
- Glyceraldehyde
- Glycerol
- Glycerol-3-phosphate
- Dihydroxyacetone-phosphate
- GNG/GL
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- Fructokinase
- ATP → ADP
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Fructose-1-phosphate aldolase
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Fructose-1-phosphate aldolase
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- Aldehyde dehydrogenase
- H2O →
- NAD+ → NADH + H+
Oxidation - Animals
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- Glycerate kinase
- ATP → ADP
Oxidation - Animals
Draw galactolysis
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- Alcohol Dehydrogenase
- NADH + H+ → NAD+
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- Glycerol kinase
- ATP → ADP
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- Glycerol-3-phosphate DH
- NAD+ → NADH + H+
Draw galactogenesis
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Sources of galactose
- Lactose
- Chondroitin sulphate
Give the steps of galactogenesis → Forming lactose
- Glucose
- Glucose-6-phosphate
- Glucose-1-phosphate
- UDP Glucose
- 1-UDP-galactose
- Lactose-1-phosphate
- Lactose
Give the steps of galactogenesis → Forming chondroitin sulphate
- Glucose
- Glucose-6-phosphate
- Glucose-1-phosphate
- UDP Glucose
- 1-UDP-galactose
- 2-amino-1-UDP-galactose
- N-acetyl-2-amino-1-UDP-galactose
- Chondroitin
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- Hexokinase
- ATP → ADP
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Phosphoglucomutase
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- UDP-glucose pyrophosphorylase
- UTP → PPi
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4-epimerase
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- Lactose-1-phosphate synthase
- Glu-1-p → UDP
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- Lactose-1-phosphate phosphatase
- → Pi
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Gln → Glu
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AcCoA → HSCoA
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UDP-glucuronate → UDP
Galactogenesis occurs in…
- Mammary gland (Lactose)
- Bone/cartilage (Chondroitin sulphate)
Lactolysis occurs in…
Small intestine
Give the steps of galactolysis
- Galactose
- Galactose-1-phosphate
- UDP-galactose
- UDP-glucose
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- Galactokinase
- ATP → ADP
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- Galactose-1-phosphate uridyl-transferase
- UDP-glucose → Glucose-1-phosphate
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4-epimerase
After galactolysis, the UDP-glucose is used in…
- Glycogenesis
- Chondroitin sulphate
- Lactogenesis
Give the composition of milk
- Dry matter = 13 %
- Milk protein = 3.3 %
- Milk fat = 3.5 %
- Milk sugar = 4.8%
- Water = 87%
List the proteins found in milk
- Casein
- α-lactalbumins
- β-lactalbumins
- Milk serum albumin
- Immunoglobulins
List the fats found in milk
- Triacylglycerols
- FFA
- Cholesterol
Effect of cellulose on milk fat
- Cellulose ↑
- Saliva production ↑
- pH ↑
- Microbial growth ↑
- Milk fat ↑
Effect of forage on milk fat
- Forage ↑
- Starch ↑
- pH ↓
- Propionic acid ↑
- Milk fat ↓