the nitrogen cycle - paper 2

Question 1

how much nitrogen is in the world?

Answer 1

78 percent

Question 2

is nitrogen reactive?

Answer 2

NO it’s very unreactive

Question 3

Nitrogen is needed to make….

Answer 3

PROTEINS

Question 4

why do animals and plants need nitrogen to react?

Answer 4

• they need protein from nitrates
• they get it from eating plants or each other
  but first it has nitrogen has to become nitrates

Question 5

what is the nitrogen fixation?

Answer 5

it is the process if turning N2 from the air into nitrogen compounds in the soil for plants to use

Question 6

nitrogen fixation is done by:

Answer 6

• lightning (energy makes the nitrogen react with oxygen for nitrates)
• nitrogen-fixing bacteria

Question 7

name the four types of bacteria involved in nitrogen fixation:

Answer 7

• decomposers
• nitrifying bacteria
• nitrogen-fixing bacteria
• denitrifying bacteria

Question 8

what do decomposers do?

Answer 8

• break downs proteins and urea
• into ammonia
  = forms ammonium ions in the soil

Question 9

nitrifying bacteria does what process?

Answer 9

nitrification

Question 10

what is nitrification?

Answer 10

turns ammionium ions in decaying matter into nitrates

Question 11

nitrogen-fixing bacteria does what?

Answer 11

turns atmospheric N2 into nitrogen compounds that plants can use

Question 12

denitrifying bacteria does what?

Answer 12

• turns nitrates back into N2 gas (does not benefit living organisms)

Question 13

where do these bacteria live?

Answer 13

some live in the soil and some live in nodules on plant roofs