Tag: photosynthetic pigments

Questions Related to photosynthetic pigments

Chloroplast stroma contains

biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

  1. Chlorophyll

  2. Light dependent reaction enzymes

  3. Light independent reaction enzymes

  4. Ribosomes

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Correct Option: C
Explanation:

In photosynthesis, light-independent reactions are known as dark reactions. This process does not depend directly on the presence of light but is dependent on the products of light reaction i.e., ATP and NADPH. The dark reactions occur through Calvin cycle. They take place in the stromal matrix of the chloroplast. Chloroplast stroma contains light independent reaction enzymes which are required for the reaction. Thus, the correct answer is option C.

Where does the primary photochemical reaction occurs in chloroplast ? Where does the light reaction of photosynthesis taken place?

biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

  1. Stroma

  2. Endoplasmic reticulum

  3. Quantasome or thylakoids (Grana)

  4. Inner membrane of chloroplast

Show answer
Correct Option: C
Explanation:

In the chloroplast, the primary photochemical reactions occur. During photosynthesis, primary reactions like the light-capturing and ATP-generating reactions occur on grana. Grana are stakes of thylakoids. Quantasomes are particles found in grana. During photosynthesis, the light-dependent reactions take place on the thylakoid membranes. The inside of the thylakoid membrane is called the lumen. Light-independent reactions take place in the stroma. 

Thus, the correct answer is 'Quantasome or thylakoids (Grana).'

Which of the following absorb light energy for photosynthesis : -

biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

  1. Chlorophyll

  2. Water molecule

  3. O$ _{2}$

  4. RUBP

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Correct Option: A
Explanation:
A pigment is a compound that absorbs a particular wavelength of visible light. Chlorophyll is a green pigment contained in thylakoid membranes of chloroplasts that are used in photosynthesis by plants. The process of photosynthesis occurs when green plants use the energy of light to convert carbon dioxide (CO2) and water (H2O) into carbohydrates. Light energy is absorbed by chlorophyll, a photosynthetic pigment of the plant, while air containing carbon dioxide and oxygen enters the plant through the leaf stomata.

So, the correct answer is 'Chlorophyll'.

In which of the following parts of the plant cell does photosynthesis occur?

biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

  1. The chloroplasts

  2. The mitochondria

  3. The nucleus

  4. The endoplasmic reticulum

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Correct Option: A
Explanation:

The green parts of the plants have the chlorophyll pigment containing chloroplasts. The chloroplast is a type of plastid which plays a major role in the photosynthesis process.

From the following, an organelle containing chlorophyll is

biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

  1. Chloroplast

  2. Endoplasmic reticulum

  3. Nucleus

  4. Mitochondria

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Correct Option: A
Explanation:
A. Chloroplasts are greenish plastids which possess photosynthetic pigments, chlorophylls and carotenoids and take part in the synthesis of food. Chlorophylls contain specialised light-absorbing green pigments, therefore help in photosynthesis.
B. Endoplasmic reticulum is a network of reticulum of tiny structures scattered in cytoplasm and composed of three structures- cisternae, tubules and vesicles.
C. Nucleus is a large organelle controlling all the activities of the eukaryotic cells and consists of nuclear envelope, nucleoplasm, nucleolus and chromatin.
D. Mitochondria are cylindrical double membrane organelles and composed of outer, inner membrane, crista and matrix.
So, the correct answer is 'Chloroplast'.

Who gave chemical compositions of chlorophyll and carotenoids?

biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

  1. Park and Biggins

  2. Meyer and French

  3. Willstatter and Stahl

  4. Arnon and Benson.

Show answer
Correct Option: C
Explanation:

Chlorophyll which is an essential factor in photosynthesis was first isolated and namedby Joseph Bienaime Caventou and Peter Joseph Pelletier but the chemical composition of the same was first elucidated by the German chemist Richard Willstatter followed by Hans Fischer.  Carotenoids which are the organic pigments found in the chloroplasts and chromoplasts of plants and other photosynthetic organisms. These  are oil-soluble molecules comprising of 40 branched carbon units bonded together.

Cytochrome is a :

biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

  1. Mg containing pyrrole rings

  2. Fe containing porphyrin ring

  3. Nucleotide

  4. Alloy of inchrome.

Show answer
Correct Option: B
Explanation:

(B) Fe containing Porphyrin ring 


Cytochromes are heme proteins that undergo oxidation Reduction reaction and differentiated on the Basis of 

their apoprotein structure, heme structures, and optical absorption in the visible spectrum.

As cytochromes are heme proteins which contain Iron compound in the Tetrapyrrole/Porphyrin structure.

Option B is correct.

If 24 G-3-P molecule are formed in $C _3$ plants. Calculate 
a) the number of $CO _2$ used and 
b) the number of $G3P$ used for regeneration $RuBP$ molecule.

biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

  1. a=12, b=20

  2. a=24, b=48

  3. a=12, b=24

  4. a=20, b=12

Show answer
Correct Option: C
Explanation:
All together for one G3P to leave the cycle (and go towards glucose blend), three CO2 particles must enter the cycle, giving three new molecules of settled carbon. At the point when three CO2 particles enter the cycle, six G3P atoms are made. One leaves the cycle and is utilized to make glucose, while the other five must be reused to recover three atoms of the RuBP acceptor. 
3 CO2 joins with 3 RuBP acceptors, making 6 atoms of (G3P). 
1 G3P particle leaves the cycle and goes towards making glucose. 
5 G3P particles are reused, recovering 3 RuBP acceptor atoms.
So, the correct option is 'a=12, b=24'.

The number of pigment molecules in quantasome are

biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

  1. 250 - 400

  2. 300 - 900

  3. 500 - 600

  4. 50 - 100

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Correct Option: A
Explanation:
  • The thylakoid membrane of chloroplasts contain around 250-400 particles known as quantasomes. They are present on the surface of thylakoid discs in chloroplasts.

What percentage of water, proteins, lipids and pigments are present in chloroplasts respectively?

biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

  1. 50, 25, 15 and 10

  2. 90, 5, 2 and 3

  3. 95, 2, 1 and 2

  4. 85, 10, 3 and 2

Show answer
Correct Option: B
Explanation:

The chloroplasts are composed of the carbohydrates, lipids, proteins, chlorophyll, carotenoids (carotene and xanthophylls), DNA, RNA and certain enzymes and co-enzymes. The chloroplasts also contain some metallic atoms as Fe, Cu, Mn and Zn. By chemical analysis, these consist of lipids and proteins basically. Lipids are mainly phospholipid components of the membranes and lamellae. Proteins also contain enzymes, which are fully present in mature plastids. By the chemical analysis, it is observed that chloroplastids contain 90% of water, 5% of proteins, 2% of lipids and 3% of pigments.