Bio 101- Energy (part 1)

energy

energy

-The ability to do work

• rearrange molecules

• fix broken parts

• reproduce

• traffic substance in and out of cell

Energy on earth is evident from what?

Volcanos and Geyers

potential energy

-stored energy; will be released/converted later and will cause motion in system

-cells store energy in chemical bonds (like ATP)

• ex: food

kinetic energy

-causing motion of atoms/molecules

• ex: muscle contraction

Adenosine Triphosphate (ATP)

-stores energy temporarily (short term) & release energy for cellular functions

• Mitochondria

• Energy Currency

• 1 adenine & 3 phosphates

First Law of Thermodynamics

-energy cannot be created or destroyed, only transferred or transformed

• energy is constant

• dependent on changing state/form of energy

• Example: Photosynthesis take light energy and convert to chemical (food).

• H20+CO2 → O2 + C6H12O6

Second Law of Thermodynamics

-converted energy is not 100% efficient/ stored energy lost when converting.

• entropy (randomness/energy that cannot be used to work) or disorder

metabolism

-summation of all the chemical reactions which occur in living bodies

• body converts food into energy (digest)

chemical reactions

-result of molecules and energy interacting w/ one another.

• New molecules

• New form of energy

Endergonic Reactions

-requires an input of energy to occur; stores input energy

• Kinetic being converted to potential

• The products have higher energy than the reactants.

• Examples = photosynthesis

• Opposite of exergonic reactions.

Exergonic Reactions

-chemical reaction releases energy.

• products have less energy than the reactants.

• examples = cellular respiration: the breakdown of glucose resulting in energy release

metabolic pathway

-a set of events which results in the removal of waste and storage of energy

• Ex. DNA

oxidation-reduction (“redox”)

-transfer of electrons.

• one substance loses electrons (oxidation)

• another substance gains electrons (reduction)

reduction

-gain electron (endergonic & constructive)

oxidation

-loss of an electron (exergonic &destructive)

electron transport chain

-result of specialized proteins which pass electrons, protein to protein

couple reactions

-result of recycling ATP molecules.

• When ATP is used, it forms an Adenosine Diphosphate molecule (ADP) plus and inorganic phosphate (Pi) which can be attached by the input of some sort of energy and metabolic pathway.

When is energy transferred?

-when a phosphate is released from one molecule to another

The 2 new molecular conditions (possible from transfer)

1. New shape of the target molecule

   -may open transport protein to allow motion in matter

2. May increase chance of the atom/molecule bounding with another atom/molecule

third phosphate

-very unstable; won’t stay bounded for long

Long term energy storage

-Starch = plants

-Glycogen = animals

-Fats

Enzymes

-Organic molecules which increase rate of chemical reaction

• build DNA

• digest food

• store energy

• transfer info

Common organelles

• Mitochondria

• Lysosomes

• Peroxisomes

Activation Energy

-amount of energy necessary for a chemical reaction to occur

• input is necessary

4 steps of the process for Enzymes to lower activation

1. Put substrates (reactants) together

2. Orient substrates in the proper place

3. move water out of way

4. change shape of molecule so it will fit

The Active Site

-portion of protein where molecules fit in enzymes

• Where enzymes do work

Enzyme Substrate Complex

-created when active sites accept the substrate

• reaction is completed

• products released

phosphorylating

-the transferring of a phosphate from one molecule to another