Nitrogen

Question 1

From what nitrogen fixing bacteria do we get out nitrogen?

Answer 1

Diazatrophs

Question 2

What do diazatrophs have the ability to do?

Answer 2

Take gaseous nitrogen and turn it into molecules containing nitrogen

Question 3

Can humans breathe in nitrogen?

Answer 3

No

Question 4

Why do humans need nitrogen?

Answer 4

As it is a vital element for our biochemistry - used for alot of biomolecules

Question 5

Which amino acids can take nitrogen and interconvert into other amino acids?

Answer 5

Glutamate

Question 6

Before N2 can be removed from the body what must it be converted back into?

Answer 6

Glutamate

Question 7

Why is nitrogen so un-reactive?

Answer 7

Due to the triple bonds between the atoms

Question 8

What do root nodules on legumes contain?

Answer 8

Rhizobium bacteria

Question 9

What is rhizobium bacteria?

Answer 9

Nitrogen-fixing bacteria

Question 10

What enzyme does nitrogen fixation require?

Answer 10

Nitrogenase

Question 11

What is alot of needed in nitrogen fixation?

Answer 11

Energy

Question 12

What effect does oxygen have on nitrogenase?

Answer 12

It inactivates it

Question 13

How does nitrogenase live?

Answer 13

Anaerobically

Question 14

What do leguminous plants produce to keep O2 levels low?

Answer 14

Leghemoglobin

Question 15

What does leghemoglobin do?

Answer 15

Binds to O2 - keeping the concentration of O2 low enough to allow nitrogenase to work

Question 16

Put in the correct order nitrogen to (nitrite, nitrate, ammonium)

Answer 16

Nitrogen
Ammonium
Nitrite
Nitrate

Question 17

Flow of N from NH4+ to toher biomolecules occurs through which amino acid?

Answer 17

Glutamate

Question 18

What is the keto acid of glutamate?

Answer 18

a-ketoglutarate

Question 19

Adding NH4+ to a-ketoglutarate converts it to what?

Answer 19

Glutamate

Question 20

Removing nH4+ form glutamate converts it to what?

Answer 20

a-ketoglutarate

Question 21

What 4 amino acids are found in much higher concentrations that other a/a?

Answer 21

Alanine
Glutamate
Aspartate
Glutamine

Question 22

What are amino acids the building blocks for?

Answer 22

Proteins

Question 23

What is transamination?

Answer 23

The transferring of amino groups between different molecules

Question 24

When the amino group is taken of an amino acid what does it become?

Answer 24

Keto Acid

Question 25

In transamination what is often one of the 2 substrate pairs?

Answer 25

Glutamate

Question 26

Is transamination reversible?

Answer 26

Yes very reversible

Question 27

What is the only amino acid with the ability to leave the cell?

Answer 27

Glutamate

Question 28

Which molecules acts as temporary storage of nitrogen?

Answer 28

L-Glutamine

Question 29

What typically accepts amino groups?

Answer 29

a-ketoglutarate

Question 30

Which enzymes are needed for transamination reactions?

Answer 30

Aminotransferases

Question 31

What do aminotransferase enzymes require?

Answer 31

Pyridoxal phosphate

Question 32

What is pyridoxal phosphate and what is it made from?

Answer 32

Co-factor made from vitamin B6

Question 33

How is energy yielded from amino acids?

Answer 33

Amino acids are oxidised | They are a significant energy-yielding pathway in carnivores

Question 34

What enzyme cuts proteins into peptides in the stomach?

Answer 34

Pepsin

Question 35

What enzymes cute proteins and larger peptides into smaller peptides in the small intestine?

Answer 35

Tyrpsin and chymotrypsin

Question 36

Where are proteins broken down in the body?

Answer 36

Stomach and small intestine

Question 37

Why would cellular proteins be broken down?

Answer 37

The protein is misfolded The protein is foreign The protein is unwanted

Question 38

What is the end point of the degradation of cellular proteins?

Answer 38

Individual amino acids

Question 39

What is an essential amino acid?

Answer 39

One that the body cannot synthesised so must be obtained from our diets

Question 40

Why is glutamate transported as glutamine?

Answer 40

Because of the charge to get through the membrane

Question 41

What is the glutamate dehydrogenase reaction?

Answer 41

The two electron oxidation of glutamate | Followed by hydrolysis

Question 42

How does nitrogen enter the urea cycle?

Answer 42

Nitrgoen from carbamoyl phosphate enters the urea cycle

Question 43

How is the toxic ammonia quickly recaptured?

Answer 43

Into carbamoyl phosphate