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Question 1

Photosynthesis is the process in which energy from _____ is trapped and stored as _________ ______ in the bonds of ______ molecules such as _____.

Answer 1

Photosynthesis is the process in which energy from light is trapped and stored as chemical energy in the bonds of organic molecules such as sugar.

Question 2

Photosynthesis is performed by _____, _____, and some _____________

Answer 2

Photosynthesis is performed by plants, algae, and some microorganisms

Question 3

_________- organisms that use inorganic substances, such as water and CO2, to produce organic compounds. Most autotrophs use light as their energy source.

Answer 3

Autotrophs- organisms that use inorganic substances, such as water and CO2, to produce organic compounds. Most autotrophs use light as their energy source.

Question 4

__________- organisms that obtain carbon by consuming preexisting organic molecules. Prior to the evolution of autotrophs, heterotrophs could not have been abundant due to the limited supply of organic molecules.

Answer 4

Heterotrophs- organisms that obtain carbon by consuming preexisting organic molecules. Prior to the evolution of autotrophs, heterotrophs could not have been abundant due to the limited supply of organic molecules.

Question 5

Organisms that harvest energy from sunlight are termed _________.

Answer 5

Organisms that harvest energy from sunlight are termed phototrophs.

Question 6

Organisms that obtain energy by oxidizing chemical compounds are called ___________.

Answer 6

Organisms that obtain energy by oxidizing chemical compounds are called chemotrophs.

Question 7

All ___________ radiation, including light, consists of ______, discrete packets of kinetic energy. Each ______ has a specific ___________, the distance it moves during a complete vibration. The ______ a photon’s wavelength, the ____ energy it contains (Example: ultraviolet radiation has greater energy than infrared).

Answer 7

All electromagnetic radiation, including light, consists of photons, discrete packets of kinetic energy. Each photon has a specific wavelength, the distance it moves during a complete vibration. The shorter a photon’s wavelength, the more energy it contains (Example: ultraviolet radiation has greater energy than infrared).

Question 8

__________ cells contain several pigment molecules that capture ____ energy. The most abundant pigment, used by plants and cyanobacteria, is _________ _.

Answer 8

Photosynthetic cells contain several pigment molecules that capture light energy. The most abundant pigment, used by plants and cyanobacteria, is chlorophyll a.

Question 9

A photosynthetic pigment ______ some wavelengths of visible light and ________ others (the color of the pigment is the wavelength of light that is reflected). Example: chlorophyll a is green. Therefore, it absorbs blue and red light, but reflects green light.

Answer 9

A photosynthetic pigment absorbs some wavelengths of visible light and reflects others (the color of the pigment is the wavelength of light that is reflected). Example: chlorophyll a is green. Therefore, it absorbs blue and red light, but reflects green light.

Question 10

________ _ is assisted by accessory pigments. These pigments are of different colors, but are in lower concentrations than _________. Therefore, most leaves appear green to the eye. However, during the fall, ________ production ______, allowing for the pigment to degrade. The accessory pigments become visible, and the leaves of the tree change color.

Answer 10

Chloraphyll a is assisted by accessory pigments. These pigments are of different colors, but are in lower concentrations than chloraphyll. Therefore, most leaves appear green to the eye. However, during the fall, chloraphyll production ceases, allowing for the pigment to degrade. The accessory pigments become visible, and the leaves of the tree change color.

Question 11

_______- the outermost, transparent, waxy, waterproof covering of a leaf that reduces evaporation of water.

Answer 11

Cuticle- the outermost, transparent, waxy, waterproof covering of a leaf that reduces evaporation of water.

Question 12

________- the transparent layer of cells on the upper and lower surfaces of a leaf.

Answer 12

Epidermis- the transparent layer of cells on the upper and lower surfaces of a leaf.

Question 13

________- the inner layer of cells that contain most of a leaf’s chloroplasts and, consequently, the site of photosynthesis.

Answer 13

Mesophyll- the inner layer of cells that contain most of a leaf’s chloroplasts and, consequently, the site of photosynthesis.

Question 14

_______- adjustable pores in the epidermis that allow the leaf to obtain the CO2 necessary for photosynthesis.

Answer 14

Stomata- adjustable pores in the epidermis that allow the leaf to obtain the CO2 necessary for photosynthesis.

Question 15

The _________ is the site of photosynthesis. It consists of a ______ outer membrane enclosing a semifluid medium called the ______. Embedded in the _____ are disk-shaped membranous sacs called _________.

Answer 15

The chloroplast is the site of photosynthesis. It consists of a double outer membrane enclosing a semifluid medium called the stroma. Embedded in the stroma are disk-shaped membranous sacs called thylakoids.

Question 16

______- site of sugar production from CO2 (Calvin cycle)

Answer 16

Stroma- site of sugar production from CO2 (Calvin cycle)

Question 17

________- site of chemical reactions of photosynthesis that are dependent upon light. Photosynthetic pigments are embedded in the membrane of the thylakoids.

Answer 17

Thylakoids- site of chemical reactions of photosynthesis that are dependent upon light. Photosynthetic pigments are embedded in the membrane of the thylakoids.

Question 18

The chemical equation for photosynthesis is:

Answer 18

6CO2 + 6H2O + light energy→ C6H12O6 + 6O2

reduced, oxidized, glucose, waste

Question 19

_____ _________- light energy is converted into chemical energy in the form of ATP and NADPH

Answer 19

Light Reactions- light energy is converted into chemical energy in the form of ATP and NADPH

Question 20

_______ _______- enzymes use the energy of ATP and NADPH to convert CO2 into glucose.

Answer 20

Calvin cycle- enzymes use the energy of ATP and NADPH to convert CO2 into glucose.

Question 21

Photosynthesis begins in the cluster of pigment molecules called _________ __. _______ molecules absorb light and transfer the energy to ________ _, which in turn, ejects _ ______.

Answer 21

Photosynthesis begins in the cluster of pigment molecules called photosystem II. Pigment molecules absorb light and transfer the energy to chlorophyll a, which in turn, ejects 2 electrons.

Question 22

______ serves as an electron donor, replacing the electrons of __________ _ and producing __.

Answer 22

Water serves as an electron donor, replacing the electrons of chlorophyll a and producing O2.

Question 23

The ejected ________ are grabbed by the ______ of the electron transport chain. The _______ are transported along the ________ membrane, driving protons to be pumped from the ______ into the ______ space.

Answer 23

The ejected electrons are grabbed by the proteins of the electron transport chain. The electrons are transported along the thylakoid membrane, driving protons to be pumped from the stroma into the thylakoid space.

Question 24

An enzyme called ___ ________ transforms the gradient’s energy into _______ energy in the form of ___. As _______ are allowed to pass through a channel in the enzyme, ______ is produced that powers the enzyme to generate ___.

Answer 24

An enzyme called ATP synthase transforms the gradient’s energy into chemical energy in the form of ATP. As protons are allowed to pass through a channel in the enzyme, energy is produced that powers the enzyme to generate ATP.

Question 25

Photons stimulate ___________ _ to release two electrons. These electrons reduce a molecule of _____ to _____.

Answer 25

Photons stimulate chlorophyll a to release two electrons. These electrons reduce a molecule of NADP+ to NADPH.

Question 26

_____ serves as an electron carrier. The electrons will be used to reduce carbon dioxide in the Calvin cycle.

Answer 26

NADPH serves as an electron carrier. The electrons will be used to reduce carbon dioxide in the Calvin cycle.

Question 27

Chloroplasts and mitochondria generate ___ by ____________, but use different sources of energy

Answer 27

Chloroplasts and mitochondria generate ATP by chemiosmosis, but use different sources of energy

Question 28

Mitochondria extract ________ from organic molecules and transfer ________ energy from food to ___.

Answer 28

Mitochondria extract electrons from organic molecules and transfer chemical energy from food to ATP.

Question 29

Chloroplasts extract ________ from _____ and transform _____ energy into _________ energy (___).

Answer 29

Chloroplasts extract electrons from water and transform light energy into chemical energy (ATP).

Question 30

The Calvin cycle occurs in the ______ of the __________.

Answer 30

The Calvin cycle occurs in the stroma of the chloroplast.

Question 31

The first step of the Calvin cycle is ________ _______. In this step, a ___ molecule is combined with _______ _________(RuBP), a ____ carbon sugar. This is _________ by the enzyme _______.

Answer 31

The first step of the Calvin cycle is carbon fixation. In this step, a CO2 molecule is combined with ribulose bisphosphate (RuBP), a five carbon sugar. This is catalyzed by the enzyme rubisco.

Question 32

The ___-carbon product immediately breaks down to form two ______-carbon sugars called _______________ (PGA). PGA is eventually converted into ______ using the energy and electrons from ___ and ______ produced in the light reactions.

Answer 32

The six-carbon product immediately breaks down to form two three-carbon sugars called phosphoglycerate (PGA). PGA is eventually converted into glucose using the energy and electrons from ATP and NADPH produced in the light reactions.