Unit 2: Photosynthesis

Question 1

What kinds of organisms can perform photosynthesis?

Answer 1

plants, bacteria, and algae

Question 2

What are the inputs of photosynthesis?

Answer 2

CO2, H2O, and sunlight

Question 3

What are the products of photosynthesis?

Answer 3

glucose and oxygen

Question 4

What are the two stages of photosynthesis?

Answer 4

light-dependant reactions and light-independent reactions/Calvin Cycle

Question 5

Which stage happens first?

Answer 5

light dependant reactions

Question 6

What do the light-dependent reactions do?

Answer 6

Light-dependent reactions use photons and water to create ATP, NADPH, and molecular oxygen.

Question 7

What do the light-independent reactions do?

Answer 7

The light-independent reactions/Clavin Cycle take the ATP, NADPH, and CO2 and produce G3P, which becomes glucose, and ADP and NADP+.

Question 8

What are the conditions in an organism that are needed for photosynthesis to occur?

Answer 8

Enzymes- proteins that speed up chemical reactions
Chloroplasts- organelles whose membranes embed chlorophyll, accessory pigments, and enzymes in patterns that maximize photosynthesis
Chlorophyll- a pigment within plant cells that absorbs light

Question 9

What do chloroplasts do within plant and algal cells?

Answer 9

Organize the enzymes, chlorophyll, and accessory pigment molecules necessary for photosynthesis.

Question 10

What happens to the products of photosynthesis?

Answer 10

Glucose is stored inside the organism
Oxygen is released into the atmosphere

Question 11

What absorbs the sunlight and photons needed for photosynthesis?

Answer 11

The chlorophyll in thylakoids within the chloroplasts.

Question 12

What are the three phases of the Calvin Cycle?

Answer 12

The three phases of photosynthesis are carbon fixation, reduction, and regeneration of RuBP

Question 13

What happens in photosystem ll of photosynthesis?

Answer 13

Sunlight is absorbed into the cell and is received by the primary electron donor in the photosystem. The electron starts a chain reaction that carries the energy until it eventually reaches photosystem l.

Question 14

What happens in photosystem l?

Answer 14

The energy from the photosystem ll reenergized by sunlight and carried to be stored in ATP and NADPH chemical bonds.

Question 15

What happens in the carbon fixation phase of the Calvin Cycle?

Answer 15

CO2 combines with the five-carbon sugar RuBP becoming RuBisCo. This forms a 6-carbon molecule which instantly splits into two 3-carbon molecules.

Question 16

What happens in the reduction phase of the Calvin Cycle?

Answer 16

ATP and NADPH join the 3-carbon molecules, this creates G3P (glyceraldehyde 3-phosphates) called “half sugars”. One of the G3P molecules metabolizes as glucose. The other goes through the regeneration phase of the Calvin Cycle

Question 17

What happens in the regeneration phase of the Calvin Cycle?

Answer 17

The second G3P molecule becomes the original 5-carbon sugar molecule RuBP and is reused in the photosynthesis process

Question 18

What happens the the NADP+ and ADP after it is finished in the Calvin Cycle?

Answer 18

It is reused in the light reactions as NADPH and ATP, which it becomes after the NADP+ joins with a hydrogen molecule, and ADP gains a third phosphate.

Question 19

What does the stomata on the bottom side of plants leaves do?

Answer 19

It allows CO2 and H2O to enter and exit

Question 20

Why do plants appear green?

Answer 20

The chlorophyll pigment can only absorb red and blue light wavelengths and reflects green light which causes it to become what’s visible to the human eye

Question 21

How does light affect photosynthesis?

Answer 21

Greater light intensity increases the rate of photosynthesis to a certain extent and lower light intensity decrease the rate of photosynthesis to a certain extent