Nitrogen

Question 1

What are the main nitrogen containing molecules in the body?

Answer 1

Amino acids
Ammonia
Urea

Question 2

What are the 3 stages of protein digestion?

Answer 2

Gastric
Pancreatic
Intestinal

Question 3

What is the name of the only amino acid to be able to obtain its nitrogen from ammonia?

Answer 3

Glutamate

Question 4

How do most amino acids gain their nitrogen?

Answer 4

Through transaminase reactions from pre-existing amino acids

Question 5

What is nitrogen transported as throughout the body?

Answer 5

Glutamine and alanine

Question 6

What charge does glutamate have?

Answer 6

Negative

Question 7

What is urea formed from?

Answer 7

Ammonia

Question 8

Ammonia is formed through what reaction?

Answer 8

Oxidative deamination

Question 9

In what cycle does ammonia become urea?

Answer 9

The urea cycle

Question 10

Cyanobacteria is important for increasing what?

Answer 10

Oxygen levels

Question 11

What enzyme is required for nitrogen fixation?

Answer 11

Nitrogenase

Question 12

What is nitrogenase inactivated by?

Answer 12

Oxygen

Question 13

How do nitrogen fixing bacteria live?

Answer 13

Anaerobically

Question 14

What do leguminous plants produce?

Answer 14

Leghemoglobin

Question 15

What is the name of the only amino acid that can obtain its nitrogen directly from NH4?

Answer 15

Glutamate

Question 16

What is the name given to the transfer of amino groups between different molecules?

Answer 16

Transamination

Question 17

Is transamination reversible or non-reversible?

Answer 17

Reversible

Question 18

What is usually one of the two substrates involved in transamination?

Answer 18

Glutamate

Question 19

In transamination, an amino acid will always undergo a reaction with what?

Answer 19

An alpha-keto acid

Question 20

What do all aminotransferases rely on?

Answer 20

The pyridoxal phosphate cofactor

Question 21

What does pyridoxal phosphate do during transamination?

Answer 21

Transfers the amino group

Question 22

Where does pepsin work?

Answer 22

In the stomach

Question 23

What is pepsin’s job?

Answer 23

To cut proteins into peptides in the stomach

Question 24

Where do trypsin and chymotrypsin work?

Answer 24

Small intestine

Question 25

Digestion of dietary proteins provides a steady supply of what?

Answer 25

Amino acids

Question 26

Where do humans get their uric acid from?

Answer 26

Purines

Question 27

Where is excess glutamine processed?

Answer 27

Intestines Kidney Liver

Question 28

What do vigorously working muscles rely on for energy?

Answer 28

Glycolysis

Question 29

What can pyruvate be converted into for transport into the liver?

Answer 29

Alanine

Question 30

What is nitrogen excreted as from the liver?

Answer 30

Ammonium ion

Question 31

Which type of molecules do not pas through membranes easily?

Answer 31

Charged molecules

Question 32

Where is excess glutamate metabolised?

Answer 32

Mitochondria of the hepatocytes

Question 33

What two reactions occur withing the glutamate dehydrogenase reaction?

Answer 33

Two-electron oxidation | Hydrolysis

Question 34

Why are some amino acids termed glucogenic?

Answer 34

They feed into gluconeogenesis to produce glucose or glycogen

Question 35

What is the definition of inherited metabolic disorders?

Answer 35

Group of genetic diseases involving metabolic defects

Question 36

What are the main effects of enzyme defects?

Answer 36

Decreased formation of the product Accumulation of the substrate Increased formation of other metabolites

Question 37

The urea cycle is split between what two parts of the body?

Answer 37

Mitochondrial matrix | Cytosol

Question 38

What is the name of the regulatory enzyme in the urea cycle?

Answer 38

CPS1

Question 39

What is PKU the result of?

Answer 39

Absence of phenylalanine hydroxylase

Question 40

What type of genetic disorder is PKU?

Answer 40

Autosomal recessive

Question 41

Patients with PKU generally have a decreased what?

Answer 41

Blood tyrosine level