Tag: metabolism, cell respiration, and photosynthesis

Questions Related to metabolism, cell respiration, and photosynthesis

In plants, food formation during photosynthesis takes place

botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

  1. In root

  2. In leaf

  3. In stem

  4. In flower

Show answer
Correct Option: B
Explanation:

Photosynthesis is the process by which plant utilizes the energy obtained from sunlight to produce glucose from carbon dioxide and water. During this process, oxygen is released as the by product. It takes place in leaf cells. Leaf cells contain chloroplasts. The chloroplasts contain green pigment chlorophyll which prepares the food during photosynthesis.

Thus, the correct answer is 'In leaf'.

Red drop and Emerson effect have proved the existence of ______________.

botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

  1. Light and dark reactions is photosynthesis

  2. Two distinct photo systems is photosynthesis

  3. The supply of electrons from oxygen evolving complex

  4. Electron transport from water to NDAP$+$ across thylakoids

Show answer
Correct Option: A

When sun light hits the chloroplast, then

botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

  1. Increase in $pH$ of thylakoid lumen relative to stroma occurs

  2. A measurable decreases in $pH$ in the thylakoid lumen relative to stroma occurs

  3. A measurable decrease in $pH$ in the stroma relative to thylakoid lumen occurs

  4. The $pH$ of both stroma and thylakoid luman becomes equal

Show answer
Correct Option: B
Explanation:

When the light hits the chloroplast, the chemiosmotic potential is established by thylakoid membrane. The carriers in the electron transport chain use some of the electron’s energy to actively transport protons from the stroma to the lumen. During photosynthesis, the lumen becomes acidic, as low as pH 4, compared to pH 8 in the stroma. Therefore answer B is correct.

In plants, light-dependent reactions proceed at the

botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

  1. cytoplasm

  2. stroma

  3. plasma membrane

  4. thylakoid membrane

Show answer
Correct Option: D
Explanation:

In plants, the light reactions take place in the thylakoid membranes of organelles called chloroplasts. The light-dependent reactions use light energy to make two molecules needed for the next stage of photosynthesis: the energy storage molecule ATP and the reduced electron carrier NADPH. 

So, the correct option is, 'thylakoid membrane'.

Choose the correct answer from the alternatives given.
The first step in photosynthesis is

botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

  1. formation bf $NADPH _2$

  2. photolysis of water

  3. formation of ATP

  4. excitation of an electron of chlorophyll by a photon of light

Show answer
Correct Option: D
Explanation:

During the first stage of photosynthesis, called the light-dependent reaction, sunlight excites the electrons in the chlorophyll pigment. The organism uses this energy to create the energy carrier molecules ATP and NADPH, which are crucial for carbon fixing during the second stage. 

Thus, the correct answer is 'Excitation of an electron of chlorophyll by a photon of light.'

Photophosphorylation in chloroplast requires movement of:

botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

  1. electrons across the membrane

  2. ions across the membrane

  3. protons across the membrane

  4. electrons and protons across the membrane

Show answer
Correct Option: D
Explanation:

Phosphorylation in the electron-transport chain in the mitochondrion.

Hence the correct answer is A.

Choose the correct answer from the alternatives given.
In a plant cell, which of the following pigments participates directly in the light reaction of photosynthesis

botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

  1. chlorophyll a

  2. chlorophyll b

  3. carotenes

  4. xanthophylls

Show answer
Correct Option: A
Explanation:

Green pigments are located within the chloroplasts of plant. Chlorophyll a can participate directly in light reaction which convert solar energy to chemical energy.

Thus, the correct answer is 'Chlorophyll a.'

In the light-dependent reactions

botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

  1. carbon dioxide is fixed

  2. $CO _2$ accepts electrons

  3. ATP and NADPH are formed

  4. sugar phosphates are formed

Show answer
Correct Option: C
Explanation:

The ATP and NADPH from the light-dependent reactions are used to make sugars in the next stage of photosynthesis. The net result of this reaction is the production of 2 ATP and 9 NADPH and the photolysis of water. Light is absorbed and the energy is used to drive electrons from water to generate NADPH and to drive protons across a membrane. These protons return through ATP synthase to make ATP.

So, the correct option is ' ATP and NADPH are formed'.

When a photosystem absorbs light

botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

  1. sugar phosphates are produced

  2. electrons are transferred to ATP

  3. RuBP accepts electrons

  4. light-dependent reactions begin

Show answer
Correct Option: D
Explanation:

When photosystem II absorbs light, electrons in the reaction-centre chlorophyll are excited to a higher energy level and are trapped by the primary electron acceptors. Photoexcited electrons travel through the cytochrome b6f complex to photosystem I via an electron transport chain set in the thylakoid membrane. The light-dependent reactions use light energy to make two molecules needed for the next stage of photosynthesis: the energy storage molecule ATP and the reduced electron carrier NADPH. In plants, the light reactions take place in the thylakoid membranes of organelles called chloroplasts.

So, the correct option is, 'light-dependent reactions begin'.

Assume a thylakoid which is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes?

botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

  1. Splitting of water

  2. Absorption of light energy by chlorophyll

  3. Flow of electrons from photosystem II to photosystem I

  4. Synthesis of ATP

Show answer
Correct Option: D
Explanation:

The thylakoid membranes have pigment system, electron transport proteins as well as the ATP synthases. When the transfer of electron down the transport proteins occurs, many H$^{+}$ are transported into the thylakoid lumen from the stroma. This high concentration of H$^{+}$ is then used by the ATP synthases to make ATP by transferring these H$^{+}$ out of the thylakoid lumen in the stroma. The punctured thylakoid will not have an intact thylakoid lumen, so the concentration of the H$^{+}$ ins will not be developed. As a result, ATP synthase will not function and so ATP will not be synthesized. 

Hence, the correct answer is 'Synthesis of ATP'