Pentose Phosphate Pathway (Ben) Flashcards Preview

Y Biochemistry 2 > Pentose Phosphate Pathway (Ben) > Flashcards

Flashcards in Pentose Phosphate Pathway (Ben) Deck (9)
Loading flashcards...
1

What are the two main functions of the pentose phosphate pathway?

  1. Formation of NADPH
  2. Synthesis of Ribose-5-P

2

What are the two main functions of the NADPH created by the pentose phosphate pathway?

Synthesis of...

  • Fatty acids
  • Cholesterol
  • NTs
  • Nucleotides

Detoxification ...

  • reducing oxidized Glutathione
  • Cytochrome P450 enzymes

3

What is the function of ribose created by the pentose phosphate pathway?

Nucleotide and nucleic acid formation

4

Where does the pentose phosphate pathway occur?

cytosol

5

What are the two phases of the pentose phosphate pathway?

Their main substrates and products?

  1. Irreversible Oxidative Phase
    • substrate: G6P
    • product: ribulose-5-phosphate + NADPH
  2. Reversible Nonoxidative Phase
    • substrate: ribulose-5-phosphate
    • product: G6P Ribose Precursors

6

What is the 1st reaction of the pentose phosphate pathway?

Substrates?

Enzyme?

Product?

Note?

Dehydrogenation...

Substrate: G6P + NADP+

Enzyme: G6P Dehydrogenase

Product: 6-Phosphogluconolactone

Note: IRREVERSIBLE

7

What is the 2nd reaction of the PP pathway?

Substrate?

Enzyme?

Product?

Note?

Hydrolysis...

Substrate: 6-Phosphogluconolactone

Enzyme: Lactonase

Product: 6-Phosphogluconolactate

Note: IRREVERSIBLE​

8

What is the 3rd reaction of the PP Pathway (ignoring the intermediate) ?

Substrate?

Enzyme?

Product?

Note?

Oxidative decarboxylation...

Substrate: 6-Phosphogluconolactate + NADP+

Enzyme: 6-Phosphogluconolactate Dehydrogenase

Product: Ribulose-5-phosphate + NADPH + H+ + CO2

Note: IRREVERSIBLE​

9

What is the main disease associated with PP pathway dysfunction?

What is its main symptom and how is it triggered?

G6P Dehydrogenase Deficiency or Favism

- mainly characterized by hemolytic anemia

- symptoms brought on by oxidative stress (infection, some drugs, fava beans)