Question

Calvin-Benson Cycle AG0 (kJ/mol) +70.0 Reaction Ribulose-1,5-bisphosphate CO2 H2O 2(3-phosphoglycerate) +H Enzyme Ribulose-1,5-bisphosphate carboxylase oxygenase ЕС Cofactors Regulation Notes 4,1.1.39 Mg2, cobalamin (B,2) coenzyme-A, NADH H Fe-S clusters, and possibly ATP Ribulose-1,5-bisphosphate (RUBP) behaves as an inhibitor by strongly binding to the activated form of the enzyme (ЕСM) Rubisco activase catalyzes the dissociation of RuBP from ECM Rubisco is very inefficient as a carboxylase It is probably the most abundant protein on earth; up to 50% of leaf protein is rubisco (Feller et al., 2008) Ribulose-1,5-bisphosphate O2H2O 3-phosphoglycerate 2-phosphoglycolate+H phosnhoglvcerate kinase glvceraldehyde 3-phosphate dehydrogenase Triose phosphate isomerase Aldolase fructose-1,6-bisphosphatase transketolase Sedoheptulose-1,7-bisphosphatase phosphopentose isomerase phosphopentose epimerase. phosphoribulokinase

Answer 1

CALVIN BENSON CYCLE

Phospho glycerate kinase

EC = 2.7.2.3

Reaction - In the cycle PGK is the seventh enzyme. Catalyses the reaction of 1,3-Biphosphoglycerate and ADP to form 3-Phosphoglycerate and ATP.

Cofactor - 2,3-DPG act as a cofactor which is in the traces in majority cells.

Regulation -

1) Several multivalent anions of low concentrations like sulphate, phosphate, citrate and pyrophosphate activate the enzyme. High concentrations of Mg2+ prohibits the enzyme in a non competitive manner.

2) Salicilates inhibits the activity of PGK, and appeared as a copycat of enzyme's nucleotide substrate because of its prime specification of nuceotide substrate.

3) To increase PGK activity in vitro environments and computer simulations simulating a cell interior, Macromolecular crowding has been indicated. This crowding leads to more compact and enzymatically active enzyme.

Notes - PGK is sequentially conserved in evolution and found in all living organisms. It has a capability of existing in open conformation, gives way to substrate diffusion and products through binding sites.

Glyceraldehyde 3-phosphate dehydrogenase

EC = 1.2.1.12

Reaction - Primary Reaction is glyceraldehyde 3-phosphate (G3P) oxidises in position -1 shows that aldehyde gets transformed to carboxylic acid and reduction of NAD⁺ is happened concurrently to NADH.

$\Delta$G^o' kJ/mol = -50 kJ/mol (12 kcal/mol))

Cofactors  - NADH and NAD

Regulation - Allosteric Regulation's morpheein model is used by protein

Notes - Glyceraldehyde -3- phosphate dehydrogenase is a main enzyme in glycolysis which catalyzes pathway firststep and get converted into 3-phospho-D-glyceroyl phosphate.

Nuclear events such as RNA Transport, Transcription, apoptosis and DNA Replication includes GAPDH participation.

Triose Phosphate isomerase

EC = 5.3.1.1

Reaction - The Enzyme Triose phosphate isomerase leads to the catalysation reaction of the reversible interconversion of the triose phosphate isomers dihydroxyacetone phosphate and D- glyceraldehyde 3-phosphate.

cofactors - As Triose Phosphate isomerase is an ubiquitous enzyme, the isomerisation reaction takesplace without any cofactors.

Regulation - The regulation is not in a precise manner, whereas before two steps the enzyme is in the phosphofructokinase, glycolytic pathway, irreversible enzyme and highly regulated.

Notes - 1) It is identified in every mammals, organisms, insects, bacteria, fungi and plants.

  2) The Deficiency of Triose phosphate isomerase is an autosomal recessive or glycolsis

Aldolase

EC - 4.1.2.13

Reaction - Aldolase can also be mentioned as Fructose biphosphate aldolase, splitting of fructose 1,6-biphosphate, aldol into triose phosphates dihydroxyacetone phosphate and glyceraldehyde 3-phosphate.

Cofactor - Lack of bivalent metal cofactor, class 1 aldolase present in higher plant tissue and animals.

Regulation - Regulation of Aldolase C is primarily due to the gene expression - the mRNA concentration in the cytoplasm. which is also known as adenosine 3', 5' - cyclimonophophate. It will change the gene expression.

Notes - The enzyme Aldolase converts sugar into energy. when a person has muscle damage, aldolase level in the blood increases.

Fructose, 1-6, - biphosphatase

EC - 3.1.3.11

Reaction - Conversion of fructose 1,6 - biphosphate to fructose 6-phosphate ,Catalysation takes place by phosphofructokinase in glycolysis.

Regulation - The enzyme is highly regulated by fructose 2,6 - biphosphate