Biology Photosynthesis Chapter 10

Front 1

____ is the use of sunlight to manufacture carbohydrate

Back 1

photosynthesis

Front 2

photosynthetic organisms are termed _____, because they make all of their own food

Back 2

autotrophs "self feeders"

Front 3

humans and other non-photosynthetic organisms are termed ______, because they have to obtain the sugars and other foods they need from other organisms

Back 3

heterotrophs "different feeders"

Front 4

photosynthesis is an exergonic/endergonic set of reactions that reduces CO2 to glucose or other sugars

Back 4

endergonic, energy must be added

Front 5

cellular respiration is an exergonic/endergonic set of reactions that oxidizes glucose to CO2 and produces ATP

Back 5

exergonic, energy is gained through cellular respiration

Front 6

the reactions that reduce CO2 and produce sugar are known as the ____ cycle

Back 6

calvin cycle

Front 7

photosynthesis consists of two linked sets of reactions. what are they?

Back 7

light dependent (produce oxygen from water)
light independent (calvin cycle. produces sugar from CO2, and requires the products of the light dependent reactions)

Front 8

during the calvin cycle, the ____ and ____ produced in the light capturing reactions are used to reduce ____ to carbohydrate

Back 8

the ATP and NADH produced in the light capturing reactions are used to reduce carbon dioxide to carbohydrate

Front 9

photosynthesis takes place in the bright green organelles called ____

Back 9

photosynthesis

Front 10

a chloroplast is made of vesicle like structures called ____, which occur in stacks called ____. the fluid filled spaces between are called ____

Back 10

thylakoids occur in stacks called grana, the fluid filled space is the stroma

Front 11

___ are molecules that absorb only certain wavelengths of light. other wavelengths are reflected or transmitted.

Back 11

pigments

Front 12

pigments have colors because we see the wavelengths they do not ____

Back 12

absorb

Front 13

the most abundant pigment in the thylakoid membranes is ____

Back 13

chlorophyll

Front 14

the ____ determines the type of electromagnetic radiation

Back 14

wavelength

Front 15

which contains more energy, short or long wavelengths?

Back 15

short wavelengths contain more energy

Front 16

light exists in packets called ___

Back 16

photons

Front 17

what is a graph showing the amount of light absorbed vs wavelength?

Back 17

an absorption spectrum

Front 18

what are the two major pigments in plant leaves?

Back 18

chlorophylls (appear green, absorb blue and red) and carotenoids (appear yellow, orange, red. absorb blue and green)

Front 19

which two color photons are most effective at driving photosynthesis?

Back 19

blue and red

Front 20

_____ protect chlorophyll from harm, extend the range of photosynthesis, and are responsible for fall colors

Back 20

carotenoids

Front 21

wavelengths in the UV part of the spectrum have so much energy they may eject electrons from a pigment and create a ______

Back 21

free radical

Front 22

when a photon strikes a chlorophyll molecule, the_____ in the chlorophyll enter an excited state

Back 22

electrons

Front 23

when a photon strikes a chlorophyll and excites the electrons, the energy (but not the electron itself) is passed to a nearby chlorophyll, and excites another electron. this process is called _______

Back 23

resonance

Front 24

electromagnetic energy from the excited chlorophyll electrons are transferred to the electron acceptor at the ____ center, where chemical energy is created

Back 24

reaction center

Front 25

the redox reactions that occur in the photosystem II ETC's result in a ___ that will drive ATP production via ATP synthase.

Back 25

proton gradient

Front 26

the stroma becomes negatively ____ relative to the thylakoid lumen due to the concentration of protons in the thylakoid lumen

Back 26

stroma negatively charged relative to the thylakoid lumen, because the thylakoid lumen has an abundance of positively charged protons

Front 27

the _______ set up by photosystem II allows protons to flow out of the thylakoid lumen, through ATP synthase and into the stroma

Back 27

proton gradient

Front 28

the proton flow from the thylakoid lumen to the stroma is an exergonic/endergonic process?

Back 28

exergonic process that drives the synthesis of ATP

Front 29

_____ is the process where ATP is synthesized from ADP and Pᵢ

Back 29

phosphorylation

Front 30

photosystem II obtains electrons by oxidizing ______

Back 30

water

Front 31

what goes into photosynthesis?
what comes out of photosynthesis?

Back 31

in- water, carbon dioxide
out- carbohydrate, water, oxygen

Front 32

when excited electrons leave photosystem II and enter the ETC, the photosystem becomes so _____ that enzymes can remove electrons from water, leaving protons and oxygen

Back 32

electronegative

Front 33

______ is the only protein complex that can catalyze the splitting of water molecules

Back 33

photosystem II

Front 34

photosystem I produces ______, an electron carrier that can donate electrons to other compounds and reduce them

Back 34

NADPH

Front 35

photosystem II produces ______, which drives the synthesis of ATP.
photosystem I produces ______, an electron carrier that can reduce other compounds

Back 35

PS II produces the proton gradient to synthesize ATP
PS I produces NADPH, an electron carrier

Front 36

____ forms a physical link between PS II and PS I, shuttling electrons between the two

Back 36

plastocyanin

Front 37

_______ coexists with the Z scheme and produces additional ATP

Back 37

cyclic photophosphorylation

Front 38

____ reacts with CO2 to produce 3-phosphoglycerate, the initial product of carbon reduction

Back 38

RuBP, ribulose bisphosphate

Front 39

____ is the addition of carbon dioxide to an inorganic compound, converting CO2 to a useful form.

Back 39

carbon fixation

Front 40

what are the three phases of the calvin cycle?

Back 40

1. fixation- where CO2 reacts with RuBP
2. Reduction- where 3-phosphoglycerate is phosphorylated and reduced, producing G3P.
3. Regeneration- where G3P keeps the cycle going

Front 41

where does the calvin cycle take place?

Back 41

in the stroma of the chloroplasts

Front 42

the calvin cycle clarifies how the ATP and NADH produced by light capturing reactions allow cells to reduce _____ to ______

Back 42

the calvin cycle reduces CO2 to carbohydrate

Front 43

what is the CO2 fixing enzyme in the calvin cycle?

Back 43

Rubisco

Front 44

Rubisco is slow and inefficient because oxygen and carbon dioxide ____ and the enzymes active sites.

Back 44

oxygen and carbon dioxide compete at the active sites, slowing the rate of CO2 reduction

Front 45

carbon dioxide enters leaves through _____, made of paired guard cells creating a pore

Back 45

stomata

Front 46

the concentration gradient that allows CO2 to diffuse into the leaves is maintained by the _____, which constantly uses up CO2 in the chloroplasts

Back 46

calvin cycle

Front 47

_______ are normally open during the day, when photosynthesis is occuring, and closed at night.

Back 47

stomata

Front 48

why does photosynthesis stop when it is extremely hot and dry?

Back 48

if photosynthesis continued, the stomata must stay open to absorb CO2, and the leaf cells may loose water, dehydrate and die

Front 49

species that live in hot, dry environments use _____ to minimize photorespiration when stomata are closed and not allowing CO2 to diffuse in

Back 49

CO2 pumps like CAM or C4 photosynthesis

Front 50

____ and ____are the main photosynthetic products

Back 50

sucrose and starch

Front 51

sugars are transported in the form of ___ and stored in the form of ____

Back 51

transported in the form of sucrose, stored in the form of starch

Front 52

starch production occurs in the ___, sucrose synthesis occurs in the ____

Back 52

starch is made in the chloroplast, sucrose is synthesized in the cytosol

Front 53

sucrose, a disaccharide, is synthesized from ____ and ___. both monosaccharides.

Back 53

glucose and fructose

Front 54

when photosynthesis is proceeding rapidly, ____ is abundant and _____ is synthesized.

Back 54

sucrose is abundant, and starch is synthesized

Front 55

at night, the ____ that is temporarily stored is broken down and used to manufacture _____ for respiration

Back 55

starch is broken down at night and used to manufacture sucrose