Forms of energy

Energy is the capacity to do work

Work is transferring energy to an object causing it to move

Potential Energy- Stored energy because of location or structure

Activation energy is the energy needed to release the stored potential energy

Kinetic Energy- Movement

Thermal Energy- Transfer of kinetic energy of the random movement of atoms to other atoms

Chemical Energy- The energy stored in the bonds of macromolecules

Types of Energy important in human functioning

• Mechanical energy, which is stored in physical systems such as machines, engines, or the human body, directly powers the movement of matter. When you lift a brick into place on a wall, your muscles provide the mechanical energy that moves the brick.

• Radiant energy is energy emitted and transmitted as waves rather than matter. These waves vary in length from long radio waves and microwaves to short gamma waves emitted from decaying atomic nuclei. The full spectrum of radiant energy is referred to as the electromagnetic spectrum. The body uses the ultraviolet energy of sunlight to convert a compound in skin cells to vitamin D, which is essential to human functioning. The human eye evolved to see the wavelengths that comprise the colors of the rainbow, from red to violet, so that range in the spectrum is called “visible light.”

• Electrical energy, supplied by electrolytes in cells and body fluids, contributes to the voltage changes that help transmit impulses in nerve and muscle cells.

1st law of thermodynamics

-Energy cannot be created nor destroyed

-Energy does not disappear it gets converted into non-usable energy

2nd law of thermodynamics

-The transfer of energy increases entropy

-Living things increase the entropy of their surroundings

Chemical reactions

-ATP is an energy carrier molecule

-There are other types of energy carrier molecules like electron carriers

-Chemical energy is stored in the bonds of molecules

-Reactants- What goes in

-Products- What comes out

Exergonic Reaction- When the products have less energy than the reactants

Endergonic Reaction- When the products have more energy than the reactants

-Endergonic is making something and exergonic is using something

-When you burn sugar to get energy that is an exergonic process

-When a plant makes sugar that is an endergonic process

-A synthesis reaction is a type of endergonic reaction. It is the making of a higher energy product by bringing two things together. This requires energy.

-A decomposition reaction is breaking the bonds of a large molecule to make to smaller ones. This usually releases energy.

-An exchange reaction is an example of re-arranging molecules. This usually requires a small amount of energy but not always.

Look at these examples:

-A coupled reaction is when an exergonic reaction provides the energy for an endergonic reaction. This is how most of the metabolic pathways work

Enzymes

-Catalysts- A catalyst speeds up a reaction. Enzymes are a biological catalyst.

-Enzymes speed up biological chemical reactions

-They lower the activation energy

pH Scale

The pH scale is a way of measuring how many Hydrogen ions (H+) are released when a molecule is dissolved in water (we call a solution of water, aqueous)

An Acid is something that releases H+ ions when it is added to water

A Base is something that releases OH- ions when added to water (Drop the Bass)

A buffer is something that releases the opposite ion causing the base or acid to become neutralized.

Our body uses many types of buffers. Different parts of our body have a different pH. Although there are different pH's throughout our body, each part must maintain the same pH. To make sure your pH does not change, your body will release buffers.

Hydrophobic-is something that does not mix with water (Afraid of water)

Usually because the molecule has no charge

Hydrophilic- is something that mixes with water (Attracted to water)

Usually because the molecule is polar