Topic 1 Flashcards
What is flow of energy
- Energy is transferred to the biological world from the sun
- Photosynthetic organisms (certain Bacteria, Algae and plants)
-Photosynthesis combines small molecules like water and oxygen into more complex compounds that are sugars
- Energy from sunlight is stored as potential energy in the chemical bonds of sugars
All about energy
definition of energy: capacity to do work
Two states of energy
Kinetic energy- energy of motion
Potential energy- stored energy
can be found in different forms: mechanical, electric current, heat, sound and light
heat is a easy way of measuring energy, in biology, energy is termed as calories
1 calorie refers to temperature needed to raise 1 gram of water by 1 degree celcius
1 kilocalorie is 1000 calorie
difference between kinetic and potential energy
kinetic- energy released when objects are in motion
potential- energy contained in the object when the object is able to move but is not moving
what are the two laws of thermodynamics
first law- energy can neither be created or destroyed, it can only change from one form of energy to another or transferred from one body to the other
second law- energy transformation or transmission is not 100 percent effecient as some energy is always unavailable resulting in a greater disorder for energy loss (distropy)
endergonic and exergonic reaction
endergonic- reaction that requires the input of energy
exergonic- reaction that occurs spontaneously and releases free energy as heat
enedergonic reaction
in endergonic reaction, the products have higher energy that the reactants (delta G is always more than 0) and additional energy is needed for the rection to proceed.
exergonic reaction
the reactants have higher energy than the products and delta G is always less than 0, the extra energy is released as heat
the reaction occurs spontaneously
activation energy is needed
activation energy is required to destabilise existing chemical bonds to initiate chemical reaction
describe activation energy in depth
activation energy is the extra energy needed to destabilise existing chemical bonds to initiate chemical reaction
the spontaneous reaction occurs more slow when there is more activation energy
the rate of reaction can be increeased by increasing the temperature or/and increasing concentration of reactants
redox reactions
an atom that gains electron is said to be reduced
an atom that loses electron is said to be oxidised
reduced forms of compounds are said to have more energy due to the potential energy that electrons hold
oxidation and reduction always occurs together as each atom that loses electron will be gained by each atom that needs an addition electron, this is called redox reaction
redox reactions are the transfer of electrons when making bonds or breaking bonds
living things gain energy from redox reactions
What is ATP
ATP fullform is adenosine triphosphate
first component present in ATP is a 5 carbon sugar called ribose that provides the framework for the other 2 subunits to attach to
The second sub unit is adenine , an organic molecule, which is made up of two carbon nitrogen rings
third sub unit is a chain of 3 phosphates
the bonds joining two terminal phosphates to ATP is referred as high energy bonds
describe the ATP cycle
- an exergonic reaction helps in providing energy to synthesising ATP from ADP + Pi which is a endergonic reaction
- the hydrolysis of ATP which is a exergonic reaction is used to supply energy to the endergonic reaction
- if hydrolysis of ATP releases more energy than the exergonic reaction can consume, by combining both reactions, the net energy release is negative delta G
- this means that the reaction will take place spontaneously
catalysis
- activation energy is not always constant
- stressing specific chemical bonds may make them weaker and helps with breaking them easily
- process that have this effect and helps in reducing the amount of activation energy needed to initiate the reaction is known as catalysis
- substance that carry out catalysis is called as catalysts
