A(n) _____ is a spur-of-the-moment question. Fill in the blank(s) with correct word.

Question

1. Accessory pigments can be molecules of chlorophyll A and a variety of other accessory pigments such as:
2. _________________________
3. _________________________
4. _________________________
5. _________________________
6. _________________________
7. These other types of pigment molecules help absorb some light at wavelengths not absorbed by chlorophyll
8. Photosynthesis is broken into two reactions

Light Dependent Stage (Photo Stage)

1. When a _______________ of light energy eventually reaches the chlorophyll A molecule at the __________________, ________ electrons from the chlorophyll A molecule are bounced out of the _________________
2. This means that the chlorophyll molecule has been ___________________
3. 
   

Answer 1

Hi, Abdulrahman!

Question 1:

Accessory pigments are light-absorbing pigments that work with chlorophyll A during photosynthesis. In terms of chlorophyll, these can include chlorophyll b (found in green algae or plants) or chlorophyll c (found in dinoflagellates - eukaryotic algae). However, this question asks for pigments other than chlorophyll. Accessory pigments will reflect light across the UV spectra (such as how chlorophyll reflects green light). There are 4 classes of accessory pigments other than the chlorophyll set (a, b, c):

1. Carotenoids - These pigments reflect red, orange, and yellow light. An example of this pigment is B-carotene!
2. Anthocyans - These ones reflect violet, blue, and red light. Examples include cyanidin and malvidin.
3. Xanthophylls - These pigments reflect yellow light. An example of this pigment is lutein!
4. Phycobilins - These pigments absorb red, yellow, green, and orange light. Examples of these include phycoerythrin and phycocyanin.

Question 2:

1. When a photon of light energy eventually reaches the chlorophyll A molecule at the thylakoid's reaction center, excited electrons from the chlorophyll A molecule are bounced out of the special pair of chlorophyll.
2. This means that the chlorophyll molecule has been oxidized.

Explanation!

1. Light energy travels in the form of photons, quantum particles that are invisible to the naked eye.
2. During photosynthesis, light is absorbed inside the chloroplast's thylakoid within a unit called a photosystem (or PS). The light energy will bounce from pigment to pigment (such as chlorophyll) inside units called the antenna/light-harvesting complexes.
3. This light energy (the photons) then moves to another section of the thylakoid known as the reaction center, where the special pair of chlorophyll inside will receive the light energy and excite an electron (raise it to a higher energy level).
4. This will then force the electron out of the special pair , where the electrons will be taken by an acceptor molecule like NADP to continue photosynthesis. Since the special pair of chlorophyll lost an electron, it has been oxidized (oxidation is the process of losing electrons - think OIL ~ Oxidation Is Losing e-). In order to make up for the lost electron, the photosystem will split a molecule of water (H₂O), producing O₂. This is why oxygen is a byproduct of photosynthesis!

Hope this helps!