Question

Review the PCR (Calvin-Benson-Basham) cycle and the photochemical (light) reactions. If photosynthesizing green algae are provided with CO2 synthesized with heavy oxygen (18O), later analysis will show that all but one of the following compounds produced by the algae contain the 18O label. That one is

Answer 1

Answer:

Explanation:

THE PHOTOCHEMICAL(LIGHT) REACTIONS :This is a phase of photosynthesis where sunlight is used as a source of energy to manufacture two chemical compounds which are "Reduced nicotinamide adenine dinucleotide phosphate"-NADPH and "Adenosine triphosphate"-ATP.This phase of photosynthesis involves 4 steps or reactions which are :

STEP 1 : Activation or Energization of chlorophyll - In this reaction,chlorophyll molecules in green algae or plants absorb sunlight and become activated,that is the electrons of the chlorophyll molecule acquire solar energy and become excited.

STEP 2 : PHOTOLYSIS OF WATER - Here the energy absorbed by the chlorophyll molecules are used to split water molecules into H+ ions and OH-- ions.

STEP 3:Formation of NADPH -The hydrogen ions (H+) produced reacts with an NADP ( an electron carrier in the chlorophyll) to form NADPH.

STEP 4: FORMATION OF ATP - The high energy generated from the electron transfer process or chain is used to add a phosphate group to ADP (Adenosine dphosphate) to form ATP.

DARK PHASE :In this phase of photosynthesis,the NADPH generated in the light phase is used as a reducing equivalent to reduce CO2 to form Glucose (food) using the ATP generated as a source of energy.