Glyceraldehyde 3-phosphate dehydrogenase

ENZYMES

Protein structure overview

Enzymes as biological catalysts

Enzymes are proteins

Enzymes reduce the activation energy of a single and specific chemical reactions

active site/unique surface structure

Enzymes are not altered by the reaction

Enzymes are biological catalysts. They stabilize the transition state from substrate to product

Many enzymes use co-enzymes (co-factors) to achive maximum activity.

metal ions, vitamins

Structure is everything!!!!!!!

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OMP

UMP +CO2

Orotidine-P decarboxylase

Working with enzymes makes you really happy!

Leonor Michaelis Maud Menten

Michaelis-Menten diagram with inhibitor and activator

Competetive inhibition

Non competetive inhibition

Lineweaver-Burk equation

-Double reciprocal plot of linear transformation of MM equation

-Y-intercept 1/Vmax

- X-intercept -1/Km

Inhibition of enzymatic reactions

competetive

uncompetetive

Non-competetive

Optimal conditions for enzymatic reactions

Temperature: optimal reaction temperature depends on environment (Thermophilus aquaticus, ice fish)

pH:amylase in the mouth (spit) peptidases and proteases in stomach

Co-factorsProstetic groups: heme, flavin, iron-sulfur groups

metal ions, (Mg2+ DNA polymerase)

Coenzymes: (vitamins), CoenzymeA (acyl groups),

NADH (dehydrogenase) – NAD- (reductase)

ATP (Kinase) – ADP (phosphatase)SAM (S-adenosyl methionine) (ACC synthase)