Energy

• Def: the capacity to do work

• 2 kinds– Kinetic

• Energy of motion

– Potential • Stored energy

Chemical Reaction Types

Exergonic

• Release energy

Endergonic

• Consume energy

• all an organisms chemical reactions• Break down complex molecules into simpler

molecules, and building complex molecules from simpler ones

ATP

• Adenosine Triphosphate

• Energy “currency” of our cells

So how does this relate to exergonic and endergonic reactions????

How does this relate to work within the cells?

In order for any reaction to occur, bonds have to be broken.

This takes ENERGYACTIVATION ENERGY energy required to get a reaction started

Good Animation

ENZYMES LOWER THE ACTIVATION ENERGY

What type of a molecule is an enzyme?????

Protein

Remember that a protein has a specific 3-D shape

Enzymes

• Show specificity (each enzyme can catalyze one / VERY few reactions)

• Are reusable (shape is unchanged)

• Lower activation energy thus speeding up the reaction rate

• Are proteins

• Destroy shape=destroy function (for all proteins)– Called denaturation

Condition

Trial 1 Trial 2 Trial 3 Average

toothpicks only

toothpicks+ nails

toothpicks and tape

Your hand was why?

Toothpick was why?

Nail was why?

Tape was why?

Inhibitors

• Competitive– Is similar to the substrate and can fit into the

active site, but no reaction occurs. Blocks the substrate from entering

• Noncompetitive– Binds to the enzyme at a place that IS NOT

THE ACTIVE SITE but changes the shape of the active site, now there’s no fit between active site and substrate

Cofactors

• Something required by enzyme in order to function– Can be inorganic (iron, zinc… remember the

trace elements?)– Can be organic (coenzyme)

• Vitamins are coenzymes

IonExamples of enzymes containing

this ion

Cupric Cytochrome oxidase

Ferrous or Ferric

CatalaseCytochrome(via Heme)

NitrogenaseHydrogenase

MagnesiumGlucose 6-phosphatase

Hexokinase

Manganese Arginase

Molybdenum Nitrate reductase

Nickel Urease

Selenium Glutathione peroxidase

ZincAlcohol dehydrogenase

Carbonic anhydraseDNA polymerase

Cofactor Vitamin Additional componentChemical group(s) transferred

Thiamine diphosphate [24]

Thiamine (B1) None2-carbon groups, α cleavage

NAD+ and NADP+ [25] Niacin (B3) ADP Electrons

Pyridoxal phosphate [26] Pyridoxine (B6) NoneAmino and carboxyl groups

Methylcobalamin [27] Vitamin B12 Methyl group acyl groups

Biotin [28] Biotin (H) None CO2

Coenzyme A [29] Pantothenic acid (B5) ADPAcetyl group and other acyl groups

Tetrahydrofolic acid [30] Folic acid (B9) Glutamate residuesMethyl, formyl, methylene and formimino groups

Ascorbic acid [32] Vitamin C None Electrons

Flavin mononucleotide [33]

Riboflavin (B2) None Electrons

Flavin adenine dinucleotide [33]

Riboflavin (B2) None Electrons

Coenzyme F420 [34] Riboflavin (B2) Amino acids Electrons

Vitamins and derivatives

Can environmental factors effect enzymes?

Enzyme source: lactase