Chapter 5: Assimilation of Inorganic Nutrients

Question 1

nutrient assimilation

Answer 1

incorporation of mineral nutrients into organic molecules

Question 2

what form of nitrogen cannot be used by a plant

Answer 2

N2 because it is stable and held on by a triple bond

Question 3

where is most of the nitrogen available in

Answer 3

the atmosphere

Question 4

phosphorylation

Answer 4

remove phosphorous group and the enzyme will be turned on

Question 5

what happens when a phosphate is attached

Answer 5

the enzyme is turned off

Question 6

phosphatase

Answer 6

enzyme that will cleave phosphates off molecules that are nitrate reductase

Question 7

what does protein kinase do in the nitrate to nitrite assimilation

Answer 7

it phosphorylates the molecule so you can bind a phosphate to it a nitrate reductase which turns it off

Question 8

what happens when there is too much nitrate in the soil

Answer 8

the plant sends it up the xylem and transports it into the stem

Question 9

what does nitrite reductase do

Answer 9

converts nitrite into ammonium

Question 10

nitrate assimilation, within the organelles there is reduction processes that ferredoxin that does what

Answer 10

moves electrons around

Question 11

what are amides and ureides

Answer 11

compounds that have nitrogen atoms in them

Question 12

ammonium assimilation

Answer 12

taking the ammonium and introducing it into amino acids

Question 13

how many enzymes are required to convert ammonium to amino acids

Answer 13

2

Question 14

transamination

Answer 14

passing amino groups from one molecule to another

Question 15

free living

Answer 15

not in association with another organism

Question 16

where are free-living symbiotic bacteria located

Answer 16

in the root system and on the nodules of the plant

Question 17

under conditions where there is not a lot of nitrogen available what will plants produce

Answer 17

heterocyst

Question 18

heterocyst

Answer 18

thick walled that does not allow for oxygen to pass through

Question 19

what kinds of environments does nitrogen fixation require

Answer 19

microanaerobic or anaerobic conditions

Question 20

explain why nitroginase enyzme cannot be in contact with oxygen

Answer 20

nitrogenase has a high affinity for electrons and oxygen is a strong electron acceptor

Question 21

what is the one gene associated with biological nitrogen fixation

Answer 21

NOD gene

Question 22

what is required to make the lipochitin oligosaccharide

Answer 22

three NOD genes to code for specific enzymres

Question 23

organogenesis

Answer 23

formation of nodules

Question 24

where does the nodule primordium form

Answer 24

opposite of xylem

Question 25

what inhibits nodule formation at the phloem

Answer 25

ethylene

Question 26

where does rhizobial infection occur

Answer 26

at the root hairs

Question 27

symbiosome

Answer 27

organelle containing the rhizobia

Question 28

the bacteria is converted into specific cells called what? that do what?

Answer 28

bacteriods; nitrogen fixation

Question 29

sulfur assimilation

Answer 29

occurs mostly in leaves; enters into the xylem and is transported up the plant to the leaves

Question 30

symporter

Answer 30

when one of the sulfates is taken up, protons will be taken up

Question 31

methionine

Answer 31

sulfur in this compound can be used to make other molecules

Question 32

what is the first step of sulfur assimilation

Answer 32

synthesis of cysteine

Question 33

cysteine is synthesized by the leaf to make what

Answer 33

glutathione

Question 34

where does the glutathione go

Answer 34

to the phloem and then moved to other parts of the plant

Question 35

roughly how much of the energy plants generate is used for nitrogen assimilation

Answer 35

25%