Photosynthesis

Question 1

Autotroph

Answer 1

‘Self-feeder’ - e.g. cyanobacteria (chlorophyll), algae, plants.
- These organisms use light energy to create chemical bonds in more complex molecules.

Question 2

Photosynthesis requires:

Answer 2

Carbon dioxide, sunlight, water

Question 3

PHOTOSYNTHESIS (definition):

Answer 3

this is the process where light energy is converted to chemical energy. Autograph organisms are the only organisms that can perform this process. The chemical energy produced is used by the autotrophs themselves in cellular respiration; but they produce enough to provide energy for heterotrophs and the entire BIOSPHERE.

Question 4

Equation of photosynthesis

Answer 4

6CO2 + 6H20 = C6H12O6 + 6O2

Question 5

CHLOROPLAST DEFINITION:

Answer 5

this is an organelle that is only found in autotrophs and consists of special green membranes called THYLAKOIDS.
These thylakoids are arranged into stacks (like a column of coins) called GRANA (plural).
The stacks can be linked by thylakoids, known as intergranal thylakoids (lamellae).
The thylakoids float in a liquid cytoplasm forming a membrane free region called the STROMA.
The thylakoids are green due to the presence of chlorophyll.

Question 6

What is the primary process by which plants convert light energy into chemical energy?

Answer 6

Photosynthesis

Question 7

True or False: Photosynthesis occurs only in the roots of plants.

Answer 7

False

Question 8

What are the main reactants in the photosynthesis equation?

Answer 8

Carbon dioxide and water

Question 9

Fill in the blank: The overall equation for photosynthesis is 6CO2 + 6H2O + light energy → C6H12O6 + 6O2. The product glucose is represented as ______.

Answer 9

C6H12O6

Question 10

Which organelle is primarily responsible for photosynthesis in plant cells?

Answer 10

Chloroplast

Question 11

What pigment absorbs light energy for photosynthesis?

Answer 11

Chlorophyll

Question 12

Multiple choice: Which wavelength of light is least effective for photosynthesis?

Answer 12

Green light

Question 13

What is the name of the light-dependent reactions of photosynthesis?

Answer 13

Photophosphorylation

Question 14

True or False: Oxygen is a byproduct of photosynthesis.

Answer 14

True

Question 15

What are the two main stages of photosynthesis?

Answer 15

Light-dependent reactions and the Calvin cycle

Question 16

Fill in the blank: The Calvin cycle occurs in the ______ of the chloroplast.

Answer 16

stroma

Question 17

What is the main purpose of the light-dependent reactions?

Answer 17

To convert solar energy into chemical energy (ATP and NADPH)

Question 18

Which molecule is produced during the light-dependent reactions?

Photosynthesis

Answer 18

ATP & NADPH

Question 19

What enzyme catalyzes the fixation of carbon dioxide in the Calvin cycle?

Answer 19

Ribulose bisphosphate carboxylase/oxygenase (RuBisCO)

Question 20

True or False: Photosynthesis only occurs during the day.

Answer 20

False

Question 21

What is the significance of photosynthesis to life on Earth?

Answer 21

It produces oxygen and organic compounds that are essential for life.

Question 22

Fill in the blank: The process by which plants release oxygen and take in carbon dioxide is called ______.

Answer 22

Photosynthesis

Question 23

What factor can affect the rate of photosynthesis?

Answer 23

Light intensity, carbon dioxide concentration, and temperature

Question 24

Multiple choice: Which of the following is NOT a product of photosynthesis?
Oxygen
Glucose
Carbon dioxide

Answer 24

Carbon dioxide

Question 25

What happens to the glucose produced in photosynthesis?

Answer 25

It can be used for energy, stored as starch, or converted into other organic compounds.

Question 26

True or False: All living organisms can perform photosynthesis.

Answer 26

False

Question 27

Fill in the blank: The light-independent reactions are also known as the ______ cycle.

Answer 27

Calvin

Question 28

What is photolysis in the context of photosynthesis?

Answer 28

The splitting of water molecules to release oxygen.

Question 29

Multiple choice: Which plant structure is responsible for gas exchange?

Answer 29

Stomata

Question 30

Light reaction:

Answer 30

Water goes to the grana where light energy is used to split it into Hydrogen and Oxygen (catabolic reaction). The hydrogen produced in this step moves to the stroma and the oxygen produced is released into the atmosphere. As the bonds holding water together are broken, the energy released is converted into energy carrier molecules which also move to the stroma to provide the energy (chemical) for the Dark stage.

Question 31

Dark Reaction:

Answer 31

in the stroma, CO2 and H2 from step 1, along with the energy carrying molecules (ATP; NADPH) result in the combination of CHO into the molecule we call glucose - C6H12O6.

Question 32

Thylakoid

Answer 32

A membrane-bound structure found inside chloroplasts where the light-dependent reactions of photosynthesis occur. It contains chlorophyll and other pigments that capture light energy to produce ATP and NADPH. Thylakoids are stacked into structures called grana.

Question 33

Grana

Answer 33

Stacks of thylakoids within the chloroplast where the light-dependent reactions of photosynthesis take place. They increase the surface area for capturing light energy and are connected by lamellae.

Question 34

Lamellae

Answer 34

Thin membranous structures in chloroplasts that connect grana, helping to maintain their structure and facilitate the exchange of molecules between thylakoids. They play a role in photosynthesis by aiding in the distribution of light energy.

Question 35

How does light effect rate of photosynthesis?

Answer 35

The rate of photosynthesis increases with light until some other factor – eg: CO2 concentration – becomes rate limiting.

Question 36

How does CO₂ Concentration effect Photosynthesis Rate?

Answer 36

Higher CO₂ increases photosynthesis because CO₂ is a raw material for the Calvin cycle. Plateaus at high CO₂ levels when other factors (light, temperature) become limiting.

Question 37

How does temperature effect rate of photosynthesis?

Answer 37

Increases with temperature as enzymes work faster. Peak at an optimum temperature (usually 25–35°C for most plants). Declines at high temperatures as enzymes (e.g., Rubisco) denature.

Question 38

Limiting factors (Photosynthesis)

Answer 38

Increase in light intensity increases rate of photosynthesis up to a certain point, when light saturation point is reached (1). Carbon dioxide becomes a limiting factor. Carbon dioxide is a reactant/substrate required by plants for photosynthesis to make glucose (1) so if carbon dioxide is constant then so will be the rate of photosynthesis as it is an enzyme driven biochemical reaction (1).