1. Fit Happens

2. What factors affect your metabolic rate?
Metabolism
The sum total of all anabolic
and all catabolic reactions
occurring in an organism.
What factors affect your metabolic rate?
Basal Metabolic Rate = minimal caloric requirement needed to
sustain the life in a resting individual
Age, Gender, Caffeine, Nicotine ,Exercise
Height ,Pregnancy, Breast Feeding
Food Intake, Starving, Malnutrition ,Couch Potato
muscle, liver, brain, kidney have high energy needs
High fever, High Stress, Environmental Temperature Change
Thyroid Function, Oxygen Consumption, Mitochondrial Function
Body Mass, Gene Expression—insulin/glucagon
Heat Production = Thermogenics

3. Chemical reactions in most organisms
take place within a narrow range of temperatures.
These narrow ranges of temperatures
are not high enough to supply
the energy need to get the reaction started…

4. Enzymes Lower energy needed to start reactions (catalysts)
Speed up chemical reactions
Reusable—not used up in reactions
Work on specific substrates (depends on the enzymes active site)
Affected by temperature, pH, concentrations…

5. Hydrogen Peroxide
Catalase or
Peroxidase
2H2O2 O2
2H2O +

6. Enzyme-Substrate Complex
H2O O2
2H202
H2O
Active Site
Catalase
Catalase
Catalase
Substrate breaks down
Enzyme is recycled.
Hydrogen Peroxide joins
With the enzyme catalase
Enzyme changes shape to
fit and hold the substrate

7. Most biological enzymes are proteins. Not all proteins are enzymes,
but most enzymes are proteins.
They perform the chemical reactions in cells.
A catalyst is a molecule which
increases the rate of a reaction.
A substrate is a molecule upon which
an enzyme acts to yield a product.
Enz
A > B

8. lactose -----------------------> glucose + galactose
Here’s one example,
b-galactosidase catalyzes the following reaction
b-galactosidase
lactose > glucose + galactose

9. A --------> B -------> C -------> D -------> E
A biosynthetic pathway is made up of a series of enzymes
which take a molecule and convert it into another molecule
through a sequence of catalyzed reactions.
For example, shown below is a hypothetical pathway
composed of four enzymes, labeled 1 through 4.
These enzymes convert the molecule A into the molecule E
through a series of intermediates (B, C, and D):
A > B > C > D > E
These pathways are necessary to make the
major molecules in cells: nucleotides, amino acids,
sugars, and lipids.

10. Thyroid Gland and Metabolism

11. Fat and Mitochondria

12. Glucose Metabolism

13. Diet and Metabolism

14. Exercise and Metabolism

15. Metabolism is the sum total of all
interactions between molecules within cell environments.
The chemistry of life is organized into metabolic pathways. Metabolic pathways begin with a specific molecule,
which is then altered in a series of defined steps to form a specific product.

16. A specific enzyme catalyzes each step of the pathway.

17. affects enzyme activity.
A cell’s physical and
chemical environment
affects enzyme activity.
The activity of an enzyme
is affected by general
environmental conditions,
such as temperature and pH.
Each enzyme works best
at certain optimal conditions,
which favor the most active
conformation for the
enzyme molecule.

19. that was released by terrorists in the Tokyo subway in 1995.
Sarin is the nerve gas
that was released by terrorists
in the Tokyo subway in 1995.
Sarin binds covalently to the
R group on the amino acid serine.
Serine is found in the active site
of acetylcholinesterase,
an important
nervous system enzyme.