Gluconeogenesis

Question 1

Irreversible steps reversal

Answer 1

1. Pyruvate ——pyruvate carboxylase(atp, biotin, CO2)——–>oxaloacetate —–pep carboxykinase + GTP—–> PEP.
2. fruct-1,6- bisp ——-fruct-1,6-bisphosphatase—–>fruct-6-p
3. gluco-6-p —–gluc-6-phosphatase——->glucose

Question 2

Sources of gluconeogenesis

Answer 2

• glucogenic amino acid
• lactate
• glycerol
• propionyl coA

Question 3

Lactate into glucose

Answer 3

Lactate——LDH(NAD+–>NADH)——–>pyruvate

Question 4

Propionyl coA into glucose

Answer 4

Propionyl coA—–caboxylase(a,b,c)—–>methyl malonyl coA—–mutase—–> succinyl coA

Question 5

Glycerol into glucose

Answer 5

Glycerol ——- kinase ——>gly3p —— dehydrogenase ——>DHAP

Question 6

Amino acid into glucose

Answer 6

Pyruvate- alanine
                   Serine
                   Glycine
                   Cysteine
Oxaloacetate- aspartate
                           Aspargine
Succinyl coA- valine
                          isoleucine
                          methionine
                          threonine
Alpha-ketoglutamarate- glutamine
                                            glutamate
                                            Proline 
                                            Histidine
Fumarate- tyrosine
                    Phenylalanine

Question 7

Regulation of gluconeogenesis

Answer 7

• Induction & regression - by insulin
• Covalent modification - phosphorylation of enzymes
• Allosteric regulation - fruct-2,6-bp inhibit
Acetyl coA activate