photosynthesis

Question 1

what is photosynthesis

Answer 1

-a complex process that converts radiant energy (light) into chemical potential energy (glucose)

Question 2

what happens during photosynthesis

Answer 2

-oxygen is released into the atmosphere during photosynthesis
-enzymes in the cells are also needed for the process
-excess glucose is converted into starch

Question 3

where does photosynthesis take place

Answer 3

-in the chloroplasts of plants

Question 4

what’s the word equation for photosynthesis

Answer 4

carbon dioxide + water -> (sunlight on top) (chloroplasts on bottom) -> glucose + oxygen

Question 5

what are the two phases photosynthesis takes place in

Answer 5

-light phase (light required)
-dark phase (no light required)

Question 6

what is the light phase

Answer 6

-takes place in the grana
-radiant energy absorbed by chlorophyll transferred into chemical energy
-photolysis
-energy rich hydrogen atoms are transferred to dark phase
-oxygen is released into atmosphere
-radiant energy cause’s energy carrier ATP to be formed

Question 7

what is photolysis

Answer 7

-chemical energy splitting water molecules into energy rich hydrogen atoms and oxygen atoms

Question 8

what is the structure of a chloroplast

Answer 8

-double membrane
-granum
-lamella
-strong
-lamella

Question 9

what is the dark phase

Answer 9

-takes place in the stroma of chloroplasts
-energy rich carbohydrates (glucose) are formed
-excess glucose is stored

Question 10

what is ATP

Answer 10

-important energy carrier in cells
-cells use ATP energy to produce important molecules and helps move substances across cell membranes

Question 11

what are the factored that influence the rate of photosynthesis

Answer 11

-light
-carbon dioxide
-temperature

Question 12

what’s the importance of photosynthesis

Answer 12

-food for plants and animals
-atmospheric gasses
-cellular respiration

Question 13

What is the role of stomata in photosynthesis?

Answer 13

-Stomata are small openings on leaves that allow carbon dioxide in and oxygen out.

Question 14

How do roots contribute to photosynthesis?

Answer 14

-Roots absorb water and minerals from the soil, which are transported to the leaves for photosynthesis.

Question 15

What can the glucose produced during photosynthesis be used for?

Answer 15

Glucose can be used for (cellular respiration)

Question 16

Why is photosynthesis important?

Answer 16

• It produces food for plants and animals and helps maintain the balance of oxygen and carbon dioxide in the atmosphere.

Question 17

What is carbon fixation?

Answer 17

-The process of converting carbon dioxide (CO2) into organic molecules (like glucose) during photosynthesis.

Question 18

How can we prove that starch is produced during photosynthesis?

Answer 18

-To prove that starch is produced, a leaf is tested using iodine solution. If photosynthesis occurs, the iodine turns the leaf dark blue/black, indicating starch is present.

Question 19

What experiments show that light and carbon dioxide are necessary for photosynthesis?

Answer 19

For light, a destarched leaf is partially covered with opaque material and exposed to light. Only the uncovered part shows starch production. For carbon dioxide, sodium hydroxide (which removes CO₂) is placed in a bell jar with the plant. No starch forms without CO₂.

Question 20

How do we test if chlorophyll is necessary for photosynthesis?

Answer 20

A variegated leaf (with green and white parts) is exposed to sunlight. Only the green parts, containing chlorophyll, produce starch when tested with iodine.

Question 21

How do we test for oxygen production during photosynthesis?

Answer 21

The oxygen produced by an aquatic plant can be collected and tested using a glowing splint. If the splint re-ignites, oxygen is present.

Question 22

What are the variables in photosynthesis experiments?

Answer 22

Independent variables: Light intensity, CO₂ concentration, temperature.
Dependent variable: Rate of photosynthesis (measured by oxygen bubbles or starch production).
Control variables: Type of plant, water availability, exposure time.

Question 23

How can we measure the rate of photosynthesis?

Answer 23

-The rate of photosynthesis can be measured by counting oxygen bubbles produced by aquatic plants or by testing for starch in leaves exposed to different conditions (light, CO₂, etc.).

Question 24

How can carbon dioxide enrichment improve crop yields in a greenhouse?

Answer 24

leading to faster plant growth and higher yields.

Question 25

How does optimizing light improve greenhouse crop yields

Answer 25

longer periods, and adjusting light intensity ensures photosynthesis occurs at the optimum rate.

Question 26

How does controlling temperature in a greenhouse improve crop yields?

Answer 26

Maintaining the optimum temperature prevents enzymes from denaturing and ensures photosynthesis happens efficiently, improving crop growth.