summer 2009 workshop in biology and multimedia for high school teachers

Summer 2009 Workshopin Biology and Multimedia for High School Teachers

• Energy is a critical part of your everyday life.

• Energy is either released or absorbed in a chemical reaction. This occurs when the bonds between the atoms are broken and then the atoms rearranged.

• The food you eat is the fuel which will provide the energy you need to sustain life.


http://en.wikipedia.org/wiki/File:MyPyramidFood.svg

http://en.wikipedia.org/wiki/Carbon


http://upload.wikimedia.org/wikipedia/commons/8/8b/C-TableImage.png

Reactions that absorb energy are called


Reactions that release energy are called


http://en.wikipedia.org/wiki/File:ThermiteFe2O3.JPG

Digestion is the physical and chemical processes used to break down food into smaller molecules that can be absorbed by the human body.


http://www.whfoods.com/genpage.php?tname=faq&dbid=16

Look

http://en.wikipedia.org/wiki/File:Macaca_arctoides.png

http://www.whfoods.com/genpage.php?tname=faq&dbid=16

Metabolism refers to all the chemical reactions within an organism that breakdown molecules to release energy and all the reactions that use energy to build complex molecules. These reactions are referred to as


RELEASEENERGY

ABSORBENERGY

When we speak of When we speak of

energyenergy we are we are talking ….talking ….

http://en.wikipedia.org/wiki/File:Animal_mitochondrion_diagram_en_%28edit%29.svg

Catabolism is the process where larger molecules are broken down into smaller molecules releasing energy. The molecules are broken down into either simple sugars, glycerol and fatty acids or amino acids. This process is exothermic.


http://commons.wikimedia.org/wiki/File:Catabolism.svghttp://commons.wikimedia.org/wiki/File:FlameV1.png

http://commons.wikimedia.org/wiki/File:Catabolism.svg

Anabolism is the process where smaller molecules are combined to form larger more complex molecules. This process requires energy so it is considered an endothermic reaction.


http://commons.wikimedia.org/wiki/File:Peptidbinding.svg

The change in energy is measured in terms of heat. The amount of energy (heat) that is contained within the bonds of the reactants is compared to the amount of energy (heat) that is contained within the

bonds of the products. This is referred to as the H.


This symbol means the difference in Enthalpy.

ENTHALPYENTHALPY

• Endothermic reactions always have a positive H.

• Exothermic reactions always have a negative H.


• Enthalpy changes that are measured when reactants are in their standard states are called STANDARD ENTHALPY CHANGES.

• STANDARD ENTHALPIES are denoted by ∆ H˚. Standard states are at 25˚ C and 1 atm of pressure.

• The enthalpy change in a reaction is directly related to the amount of reactants.


Hess’s Law states that if a series of reactions are added together, the enthalpy change for the net reaction is the same as the sum of the individual reactions.

Huh?Huh?


More simply put:

2+2=4

is the same as

1+1+1+1=4

• The subject of calorimetry studies the flow of heat and heat measurements.

• Every object has the ability to absorb heat. The amount of heat that is absorbed is referred to as the heat capacity.

• The heat capacity is the amount of heat required to raise the temperature by 1˚C.

• The heat capacity depends on the composition and the amount of the substance,


The heat capacity of one gram of a substance is referred to as the SPECIFIC HEAT.



The specific heat of water is 4.184 J/g·Cº. This means that 4.184 J of heat is needed is needed to raise 1 gram of water 1ºC.

1calorie= 4.184 J

1000calories=1 kilocalorie or CAL.

http://en.wikipedia.org/wiki/File:Thermometer_CF.svg

• Kilocalories are used in nutrition.

• Calorimeters are used to figure out the calories in food sources.


https://vinstan.wikispaces.com/file/view/calorimeter.PNG

http://en.wikipedia.org/wiki/File:Nutrition_label.gif

• The catabolism of food is an oxidative reaction.

• Most of our energy comes from Calories found in fat and sugar.

• C6H12O6 (s) + 6 O2 (g) 6 CO2 (g) + 6 H2O (l)

H = -2816 kJ


EXOTHERMIC

C57H110O6 (s) + 163/2 O2 (g) 57 CO2 (g) + 55 H2O (l).

rH = -37.8 x 104 kJ


EXOTHERMIC

Twice the energy as proteins and glucose!

Fuels

and O2 C

ata

bolis

m

ATP

Cellular Processes

Anabolism

water

ADP

CO2

P

IN SUMMARY!!!Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College.

summer 2009 workshop in biology and multimedia for high school teachers

Documents

fellows of harvard college

w scienceshhmi outreach

aslife scienceshhmi

energy heat

smaller molecules

chemical reactions

larger molecules

complex molecules