Metabolism of Carbs

Question 0

Stage II Metabolism

Answer 0

Intracellular (cytoplasmic and mitochondrial)

Many pathways

Bbm -> even simpler molecules

Oxidative (require NAD+, NADP+ etc.)

Some energy produced as ATP

Question 1

General stages of catabolism

Stage 1

Answer 1

Extracellular breakdown (GI TRACT)

Complex molecules -> building block molecules (bbm)

Bbm absorbed into circulation

No energy produced

Question 2

Stage III catabolism

Answer 2

Mitochondria

A single pathway - Citric acid cycle

Oxidative 
Acetal Converted to 2CO2 
Produces precursors for biosynthesis 
Coenzymes re oxidises 
Lots of energy produced

Question 3

Carbohydrate catabolism - which stages of catabolism and structure

• general formula
• functional groups

Answer 3

Stages I & II
(CH2O)n
Contain aldehyde (-CHO) or keto (-C=O) groups
Multiple -OH groups

Question 4

Example of

1) aldohexose
2) aldopentose
3) Ketohexose

Answer 4

1) Glucose, Mannose, Galactose
2) Ribose, Deoxyribose
3) Fructose

Question 5

Complex carbohydrates

Structures, examples and usages

Answer 5

Glycogen - main storage polysaccharide in mammals, α1-4 and α1-6 glycosidic bonds, highly branched

Starch - plants, α1-4 and α1-6, less branches

Cellulose - plants, β1-4 glycosidic bonds, unbranched

Question 6

Stage I catabolism enzymes and mechanisms

Answer 6

α-1,4 bonds - pancreatic/savlivary amylases

α-1,6 bonds - isomaltase
Sucrase
Lactase
Monosaccharides released, absorbed via transport proteins (GLUT-1 - GLUT5) and further metabolised (stage II)