chapter 7

Question 1

what is photosynthesis?

Answer 1

a process used by certain organisms to convert solar energy into chemical energy and make carbohydrate molecules

Question 2

what happens to the chemical energy created in photosynthesis?

Answer 2

it is released when food is broken down and harvested in cellular respiration

Question 3

what happens as a result of photosynthesis?

Answer 3

oxygen is released into the environment.

Question 4

what does photosynthesis use?

Answer 4

sunlight, carbon dioxide, and water

Question 5

what are the two stages of photosynthesis?

Answer 5

the light dependent cycle and the calvin cycle

Question 6

what happens when you combine carbon dioxide and water using energy from sunlight?

Answer 6

you get sugar and oxygen

Question 7

what is the structure of the leave constituent of?

Answer 7

upper epidermis, mesophyll, and lower epidermis

Question 8

where is the chloroplast located?

Answer 8

in the cells of the mesophyll

Question 9

why do autotrophs convert light energy into chemical energy?

Answer 9

to build carbohydrate molecules

Question 10

visible light constitutes…

Answer 10

only one of many types of electromagnetic radiation emitted from the sun

Question 11

when does light energy enter the process of photosynthesis?

Answer 11

when pigments absorb the light

Question 12

what is the purpose of light-dependent reactions?

Answer 12

to convert light energy into chemical energy

Question 13

where is the chemical energy created in light-dependent reactions used?

Answer 13

in the calvin cycle, to fuel the assembly of sugar molecules

Question 14

what is the first step of the light-dependent reaction?

Answer 14

a photon strikes photosystem ll

Question 15

what happens after a photon strikes photosystem ll?

Answer 15

energy travels through the electron transport chain

Question 16

what happens when energy travels through the electron transport chain?

Answer 16

hydrogen ions are pumped into the thylakoid space

Question 17

what happens when hydrogen ions are pumped into the thylakoid space?

Answer 17

an electrochemical gradient is formed

Question 18

what happens after an electrochemical gradient is formed?

Answer 18

The ions flow through ATP synthase from the thylakoid space into the
stroma in a process called chemiosmosis to form molecules of ATP

Question 19

what happens after chemiosmosis?

Answer 19

photosystem l absorbs a second photon

Question 20

what happens after photosystem l absorbs a second photon?

Answer 20

an NADPH molecule is formed

Question 21

what do the calvin cycle reactions do?

Answer 21

they fix CO2 from the environment to build carbohydrate molecules

Question 22

what catalyzes the fixation reaction of the calvin cycle?

Answer 22

RuBisCO

Question 23

how does RuBisCO catalyze the fixation reaction?

Answer 23

by combining CO2 and RuBP

Question 24

what are the three basic stages of the calvin cycle?

Answer 24

fixation, reduction, regeneration

Question 25

how many turns of the calvin cycle does it take to fix six carbon atoms from CO2?

Answer 25

it takes six turns of the calvin cycle

Question 26

how much energy input do the six turns of the calvin cycle require in the reduction stage?

Answer 26

12 ATP molecules and 12 NADPH molecules

Question 27

how much energy input do the six turns of the calvin cycle require in the regeneration stage?

Answer 27

6 ATP molecules

Question 28

when are the ATP and NADPH molecules made?

Answer 28

in the light-dependent reaction stage