Different Compounds

Question 1

Synthase vs synthetase

Answer 1

Synthetase must cleave ATP to function

Synthase does not have to cleave ATP

Question 2

Kinase

Answer 2

Plays a role in phosphorylation reactions

Question 3

Porphyrins

Answer 3

Synthesized from succinyl-CoA and glycine
N and C atoms derived from glycine and acetate
Reaction catalysed by §-aminolevulinic acid synthase
- decarboxylation calalysed by PryP

Question 4

condensation of §-aminolevulinate

Answer 4

catalysed by porphobilinogen synthase

Produces porphobilogen

Question 5

Condensation of 4 porphobilogen molecules

Answer 5

Catalysed by porphobilogen deaminase
-eliminates amino group
Produces heme

Question 6

Creatine

Answer 6

Nitrogenous organic acid that occurs naturally in vertebrates
Helps supply energy to cells (muscle) by forming ATP
-ergo essential nutrient
Human Blood contains 1% creatine

Question 7

Biosynthesis of creatine

Answer 7

From arginine and glycine

1: condensation of arginine and glycine
- (arginine:glycine amidotransferase)
2: methylation of guanidoacetate
- (guanidoacetate-N-methyltransferase)—> SAM = methyl donor

Question 8

Biosynthesis of creatine location

Answer 8

Liver and kidney

-transported to muscles through blood

Question 9

Biosynthesis of SAM

Answer 9

Synthesised from ATP and methionine
-> methionine adenosyltransferase
Methyl carrier
Assists in transsulfuration

Question 10

SAM ethylene synthesis enzymes

Answer 10

ACC synthase then ACC-oxidase

Volatile plant hormone that functions for seed germination and fruit ripening

Question 11

SAM in polyamine synthesis

Answer 11

1: SAM decarboxylated by adenosylmethionine decarboxylase
- results in S-adenosylmethioninamine
2: S-adenosylmethionamine donates n-propylamine group
- results in polyamine

Question 12

Bile salts

Answer 12

Steroids in bile with detergent properties

Oxidation of cholesterol by cytochrome P-450 enzymes in liver

Question 13

Primary bile acids

Answer 13

Synthesised by liver

• cholic acids
• chenodeoxycholic acid

Question 14

Secondary bile acids

Answer 14

Bacterial action in colon

• Lithocholic acid
• Dexycholic acid

Question 15

Major bile salts in humans

Answer 15

Taurocholic acid
Glycocholic acid
Glycochenodeoxycholic acid
Taurochenodeoxycholic acid

Question 16

Bile salt biosynthesis

Answer 16

Before acid secreted they are conjugated to glycine or taurine
-forms 8 possible conjugated bile acids
Lots of reactions, with a total of 14 enzymes in all that are involved in synthesis of bile salts

Question 17

Pigments

Answer 17

Melanin - broad term for naturally occurring pigments
Produced in melanocytes
Tyrosinase is inhibited at normal body temp but active in cooler areas of skin at extremities (paws, tail, ears) and head

Question 18

Pigment biosynthesis

Answer 18

Conversion of tyrosine to L-DOPA by tyrosinase
Inhibition of enzyme results in albinism
Oxidation of tyrosine followed by polymerization

Question 19

Thyroid hormone

Answer 19

Iodine is condensed to tyrosine residues
-takes place on thyroglobulin
(MIT and DIT)
Iodotyrosine molecules couple together
-2 DIT = thyroxin (T4)
- 1 MIT + 1 DIT = tri-iodothyronine (T3)

Question 20

Catecholamines

Answer 20

Hormones (epinephrine, dopamine, norepinephrine)
Derived from tyrosine and phenylalanine
-phenylalanine hydroxylase

Question 21

Catechol

Answer 21

Benzene ring with 2 hydroxyl side groups at C1 and C2

Question 22

Creatine enzymes

Answer 22

Arginine:glycine amidotransferase
Creatine phosphokinase
Guanidinoacetate-N-methyltransferase (SAM IS DONOR)

Question 23

SAM

Answer 23

S-adenosylmethionine

Question 24

Polyamine function

Answer 24

Regulation in replication, transcription and translation

Leading to cell proliferation, differentiation and cell death

Question 25

Phenylalanine to tyrosine

Answer 25

Hadroxylation

Phenylalanine hydroxylase