Biochemical reactions su2020 worksheet PDF

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Biochemical reaction based on Ch.13 sections 2 and 4 of Lehninger's Principles of Biochemistry 7th ed ...

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BCHE 5180 Auburn University

Biochemical reactions Dr. Kyle R. Willian

Why It is important to identify common chemical reactions and transformations that occur in the cell. Outcomes I. Be able to identify the five basic types of chemical reactions that occur in cells. a. Make or break C-C bond i. Aldol condensation ii. Claisen ester condensation iii. Decarboxylation b. Intramolecular Rearrangements and eliminations. (No change in overall oxidation state of the compound). i. Rearrangement ii. Isomerization iii. Elimination c. Free radical d. Reduction and Oxidation (REDOX) i. Direct electron transfer ii. As hydrogen atoms (H+) iii. As hydride ion (:H) e. Group transfer i. Phosphoryl ii. Thiol esters

I

Information (sections 13.2-13.4 in the textbook) Critical Thinking Questions 1. Classify each reaction in Model 1 below using the outline in the outcomes above. [figure 13-4 will also help]. Some reactions fit more than one category. Reaction I is done for you. Phosphoglycerate kinase  Group transfer -Phosphoryl  Class-Transferases (2)

II

Lactate dehydrogenase  REDOX: Hydride ion transfer  Class-Oxidoreductases (1)

III

Enolase  Elimination  Class-Lyase (4)

I V

Aldolase  Make or break C-C: Aldol condensation  Class-Lyase (4)

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BCHE 5180 Auburn University

V

Biochemical reactions Dr. Kyle R. Willian

Triose phosphate isomerase  

V I

intramolecular rearrangement- rearrangement Class- Isomerase (5)

PEP carboxykinase   

Make or break C-C bond: Decarboxylation Group Transfer: phosphoryl group Class-Ligase (6)

2. Find the Aldol condensation reaction and jump to mechanism figure 14-6 on page 541. Identify the chemical properties being displayed by the carbonyl groups in this reaction. [see figures 132 and 13-3] Nucleophilic attack by the amine group on the electrophile carbonyl group causes formation of Schiff base and undergoes reverse Aldol condensation by cleaving the C_C bond

3. Find the elimination reaction and prove a key concept: the compound does not undergo a net REDOX reaction. [see figure 13-22]

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BCHE 5180 Auburn University

Biochemical reactions Dr. Kyle R. Willian

4. Find the REDOX reaction and identify the electron carrier and its mode of electron transfer (directly as H+ or :H) [see pages 519 and 522-523 and figure 13-22]. Electron is a Hydride ion transfer

5. Look at table 6-3, page 189 and categorize the reactions in Model I using the international classification system.

I. II. III. IV. V.

Transferase Oxidoreductase Lyase Lyase Ligase

For Model 2, Fill in the missing structures and names of the missing substrates and/or reactants based on the name of the enzyme. MODEL 2

I

Mannose + ATP



___Mannose-6-phosphate___

+ ADP

II NAD +H+

II I

Ribulose-5-phosphate 

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NAD+

Xylulose-5-phosphate

OH | CH2 | CH3

Hexokinase

Alcohol dehydrogenase

Ribulose 5phosphate epimerase...