Energy, Catalysis and Synthesis Flashcards
Lecture 3
What is required to carry out a chemical reaction
Source of food and energy
How does living matter create and maintain order
Via chemical reactions
What impact does a catalyst have on temperature
Lowers the required temperature for the reaction to take place. So the reaction can be carried out at lower temperatures
How can we control these reactions
Use enzymes which catalyze the reaction
How are enzyme catalysed reactions connected
In series
Define Catabolic
Catabolic pathways breakdown food into small molecules
Define Anabolic
Anabolic pathways use energy released from catabolism to synthesise other molecules that form the cell
What two things together constitute cellular metabolism
Anabolic and Catabolic pathways
How many metabolic pathways are there in living cells
over 500!!
Where is biological order derived from?
Heat energy of cells.
Where there is order, energy has gone into the system.
Nonliving systems left to themselves become siordered
State the 2nd law of thermodynamics
In an isolated system the degree of disorder can only increase
How do we quantify the amount of disorder
Using Entropy.
The greater the entropy the greater the disorder.
Systems change with greater entropy.
State the 1st law of thermodynamics
Energy is converted from one form to another but cannot be created or destroyed
Are cells an isolated system
No, they use energy to create order and release heat to generate disorder.
Where do cells obtain energy from? How does this differ between animals and plants
The oxidation of organic molecules
Photosynthesis and Respiration are complimentary processes. This transaction between plants and animals is a two way process.
Define Oxidation
OIL
Oxidation is loss of electrons from one atom to another
Dehydration = Oxidation
Define Reduction
RIG
Reduction is the gain of electrons from one atom to another
Hydrogenation = Reduction
What rules are there to both Oxidation and Reduction
The number of electrons is always conserved
Oxidation and reduction always occur simultaneously
Oxidation and reduction apply for even a partial shift in electrons
When molecules gain an electron they often gain a proton as well
How can enzymes act as catalysts
- Molecules require activation energy before undergoing chemical reactions
- Enzymes lower barriers that block chemical reactions
- Enzymes bind tightly to substrates but they are highly selective and have unique shape and active sites
They act as very effective catalysts that can speed up reactions by up to x10^14
They remain unchanged after the chemical reactions so can be use infinitely
How many substrates can one enzyme catalyse a second?
How?
1000
Through diffusion. The rate of which depends on the free energy G
