Metabolic Processes~An Application to Real Life~

Metabolism

• Metabolism = anabolism + catabolism

Metabolism

Anabolic reactions are endothermic (energy absorbed).

Catabolic reactions are exothermic(energy released).

*Enzymes catalyze anabolic and catabolic reactions.

Metabolism

Metabolic reactions are initiated by, accelerated by and/or regulated by

enzymes.

Metabolism

• Metabolism regulates how energy is used in the body (primarily dictated by the liver).

• The energy used by the body is determined by three factors:– Basal metabolic rate (BMR).– Physical activity.– Thermic effect of food (TEF).

Source: Nutrition from Science to Life – Grosvenor & Smolin

Basal Metabolic Rate

• The energy required for the maintenance of basic bodily functions (at rest).–E.g., Breathing, circulating blood, maintaining

constant body temperature, etc.

• Accounts for 60 – 75% of total energy requirement.

• View online calculator to determine resting metabolic rate (RMR) to estimate your BMR…how accurate is this number?

Source: Nutrition from Science to Life – Grosvenor & Smolin

Physical Activity

• Includes energy required to sit, stand, walk and exercise.

• Accounts for 15 – 30 % of total energy requirements.– Energy required increases with increasing

body weight.– Energy required depends on the intensity and

duration of activity.

Source: Nutrition from Science to Life – Grosvenor & Smolin

Thermic Effect of Food (TEF)

• Known as “diet-induced thermogenesis”.• Energy requirement increases several hours after

a meal, due to:– Digesting, absorbing, metabolizing & storing nutrients.

• Causes slight increase in body temperature.• TEF increases with size of meal.• TEF increases in meals high in carbohydrates

and proteins compared to meals high in fat. • Accounts for 5 – 10% of total energy

requirements.

Source: http://www.itopf.com/information-services/data-and-statistics/statistics/documents/Statpack2008_001.pdf

Source: http://www.itopf.com/information-services/data-and-statistics/statistics/documents/Statpack2008_001.pdf

In Summary

From 1970 to 2008, approximately 5.65 million tonnes of oil were lost.

BUT…the total number of spills and the amount of oil lost as a result of tanker incidents has decreased

significantly during the last 38 years.

*Although oil spills are not as frequent anymore, they are still just as lethal to environment. They are a social and

economic burden.

Cleaning up Oil Spills

1. Let it be…the oil will naturally breakdown via wind, sun, current and wave action.

2. Contain the spill with buoyant material and specialized skimmers suck or scoop the oil into storage tanks.

Cleaning up Oil Spills

3. Use of dispersants to break the oil slick into droplets that enter the water column to speed up the natural breakdown of the oil.

4. *Introducing bacteria and other microorganisms to metabolize the oils into harmless substances.

Bioremediation

A process by which microorganisms, fungi and plants (or their respective enzymes) breakdown hazardous substances into either less toxic or

nontoxic compounds.

*heavy metals (e.g., cadmium and lead) are not readily taken in by organisms - introduction of

these metals into a food web can have disastrous results!

Watch This!!!And This!!!

Why does Brazil rely more heavily on biofuels than North

American countries?

Brazil…a World Leader in Bioethanol Production

• Brazil is one of the largest bioethanol producers and is the largest exporter of this fuel (over 90% of the global export market) primarily to the US, Japan and Europe.

• All gasoline in Brazil contains ethanol (at least 20 – 25%).

• More than 50% of the cars in Brazil can run on 100% bioethanol.

• Production exceeds current demand, so exportation may increase.

Watch This!!!Source: http://www.eia.doe.gov/emeu/cabs/Brazil/Oil.html

Bioethanol

Bioethanol is produced by the fermentation of plants, such as

sugar cane, sugar beets, switchgrass

and corn.

Production of Bioethanol

• Enzymes hydrolyze the carbohydrate polymers from the plant cell walls (cellulose & hemi-cellulose) into sucrose.

• Yeast fermentation converts the sucrose into glucose & fructose (via invertase) which are then converted into ethanol (via zymase).

Source: http://www.international.inra.fr/research/some_examples/filamentous_fungi_to_produce_biofuels & http://www.esru.strath.ac.uk/EandE/Web_sites/02-03/biofuels/what_bioethanol.htm

Benefits of Bioethanol

• Burns more completely than other fossil fuels.• Biodegradable.• Renewable resource.• CO2 released as a byproduct is absorbed from

the growing fuel crops.• Blending bioethanol with gasoline will help

extend the life of the diminishing oil supplies…this can be done without engine modifications.

• Boost the economy in rural areas that grow fuel crops.

Source: http://www.esru.strath.ac.uk/EandE/Web_sites/02-03/biofuels/what_bioethanol.htm

Other Alternatives

Watch these videos…

Yeast produce biogasoline

From algae to oil

Is it healthier to eat your veggies raw or cooked?

Raw or Cooked?

• Raw vegetables typically have more minerals & vitamins and are considered to be enzyme-rich.

• BUT…there are many people who cannot properly digest raw veggies.

– Cellulose is poorly digested in humans (we lack cellulase), but is important for intestinal health.

• Suggested that vegetables are baked, simmered, sautéed or steamed rather than boiled to help retain most of their nutritional properties.

Source: http://www.bodyecology.com/06/12/14/raw_vegetables_gas_bloating.php

Raw or Cooked?

• Cooking broccoli damages myrosinase which is involved in the production of sulforaphane.– May prevent the proliferation of precancerous

cells and kill any that are present.– May fight the bacterium that causes ulcers

and stomach cancer.

• Cooking broccoli forms indole, a compound that kills precancerous cells before becoming malignant.Source: http://www.scientificamerican.com/article.cfm?id=raw-veggies-are-healthier&page=2

Raw or Cooked?

Watch these videos…

Health drawbacks to overcooking food

Enzyme supplements required