ME02 - ENZYMES : Introduction Flashcards Preview

BIOCHEMISTRY > ME02 - ENZYMES : Introduction > Flashcards

Flashcards in ME02 - ENZYMES : Introduction Deck (104)
Loading flashcards...
1

Energy required in order for reaction to occur

Activation Energy

2

Determine the direction and equilibrium states of the reaction

Free energy changes

3

Catalysts

Enzymes

4

Properties of Enzymes

Reaction-specific
Substrate-specific
Stereo-specific

5

Description for Enzymes

Increase reaction rates without being consumed or permanently altered
D sugars & L-amino acids
Typically proteins but can also be nucleotides
Affected by pH and temp

6

Non-protein catalysts with ribonuclease & peptidyl transferase activity

Ribozymes

7

What kind of gene is present in Ribozymes and its function

It contains autocatalytic RNA molecules that can adopt complex structures like proteins

8

Involved in Gene Therapy

Intron and tRNA processing

9

Enzymes classified by reaction. Complete table
Class Type of Reaction Example
Hydrolase
Isomerase
Ligase/Polymerase
Lyase
Oxidoreductase
Transferase

Class Type of Reaction Example
Hydrolase Hydrolysis Lipase

Isomerase Rearrangement of atom Phosphoglucoisomerase
within a molecule

Ligase/Polymerase Joining two or more Acetyl-CoA synthetase
chemicals together

Lyase Splitting a chemical into Fructose 1,6-BP Aldolase
smaller parts w/o using water

Oxidoreductase Transfer of electrons or Lactic acid
H atoms from one molecule dehydrogenase
group to another

Transferase Moving a functional group Hexokinase
from one molecule group to another

10

IUBMB Number corresponds to
1st number
2nd number
3rd number
4th number

1st number - Major class: Enzymes
2nd number - Subclass: Mechanism
3rd number - Sub-Subclass: Substrate Clase
4th number - Specific Substrate

11

Catalyze the oxidation of a substrate with simultaneous reduction of another substrate or coenzyme
Transfer of electrons or H atoms from one molecule to another

Oxidoreductases

12

Example of Oxidoreductase

Lactic acid-dehydrogenase - oxidizes lactic acid to form pyruvic acid during FERMENTATION

13

Moving a functional group from one substrate/molecule to another
(may be anabolic)

Transferase

14

Example of Transferase

Hexokinase - transfers phosphate from ATP to glucose in the first step of glycolysis

15

Break single bonds (ester, ether, peptide or glycosidic) by the addition of water
This is Catabolic

Hydrolysis

16

Example of Hydrolysis

Lipase - breaks down lipid molecules

17

Form or cleave bonds with group elimination non hydrolytically
Splitting a chemical into smaller parts without using water

Lyase

18

How does LYASE catalyze cleavage of C-C, C-O, C-N, and other covalent bonds

By atom elimination and generating double bonds

19

Example of Lyase

Fructose 1,6-bisphosphate aldolase - splits fructos into G3P and DHAP

20

Carry out intramolecular rearrangements
Catalyze geometric or structural changes within a molecule
(Neither catabolic or anabolic)

Isomerase

21

Example of Isomerase

Phosphoglucoisomerase - converts glucose 6 phosphate into fructose 6 phosphate during glycolysis

22

Link two substrates together usually with the Hydrolysis of ATP
Joining two or more chemicals together coupled with ATP hydrolysis

Ligase or Polymerase

23

Example of Ligase/Phosphorylase

Acetyl-CoA synthetase - combines acetate and coenzyme A to form acetyl-CoA for the Krebs Cycle

24

ENZYMES THAT HAS Catabolic Reactions

Hydrolases - Lipase
Lyase - Fructose 1,6-Bisphosphate aldolase

25

ENZYMES THAT HAS Anabolic Reactions

Transferase - Hexokinase
Ligase/Polymerase - AcetylCoA synthetase

26

ENZYMES THAT HAS Neither Catabolic and Anabolic Reactions

Isomerase - Phosphoglucoisomerase

27

Where does Catalysis occur
The site on the enzyme where the substrate binds to

at the ACTIVE site
Active Site - cleft or pocket on the enzyme

28

Events happening on the Active Site of Enzyme

Desolvation effects
Binds substrates properly for transition state formation
Binds cofactors & prosthetic groups

29

Factors for substrates' transition state formation properly

Geometric & Electronic complementarity

30

Substrate-binding sites are largely preformed but some degree of induced-fit usually occurs on

Lock & Key model by Emil Fischer
Induced Fit model by Daniel Koshland