Energy Concepts in Biology: Thermodynamics, Reactions, and Cell Processes

what is energy

the capacity to do work

when can you tell if work has been done

when something has moved

2 main types of energy

kinetic: the energy of movement; if an object, photon, molecule is in movement it is exhibiting KE

potential: stored energy including chemical energy stored in bonds and positional energy

thermodynamics

The study of energy transformations that occur in a collection of matter.

first law of thermodynamics

energy cannot be created or destroyed, simply transferred or transformed

second law of thermodynamics

when energy conversion takes place, the amount of useful energy decreases

- energy is spontaneously converted from more useful to less useful forms.

NO ENERGY CONV IS 100% EFFECTIVE

living organisms maintain order. by using ENERGY, but... because no energy conversion is 100% effective, disorder in universe still increases

less energy =.... more energy =....

less=more disorder more=less disorder

regions of concentrated energy=

highly ordered

entropy

tending toward loss of orderliness and high-level energy and an increase in randomness/disorder

living things use energy of sunlight to create LOW entropy

more energy = lower entropy

life and how to maintain order

life is special because living organism maintain low entropy conditions meaning they stay highly organized instead of facing apart

huge amount of energy is lost as

heat

how does energy flow in chemical reactions

in chemical reactions break bonds requiring energy forming new bonds releasing energy

All reactants converted into products

EXERGONIC REACTIONS

reactants contain more energy than the products

example of exergonic reaction

when sugar (glucose) is coupled with oxygen and burned ion the body we get energy and release CO2 and H20

know eco and endo graph

and explain

Activation energy

energy necessary to spark reaction

why do we need activation energy

necessary because negatively charged electron shells that surround atoms and molecules naturally repulse eachther

For reaction to occur these 2 molecules must be forced together this requires energy

The useful source of this energy is via KE where molecules moving with enough speed will collide hard enough to force their electron shell to transfer valence electrons

why. do reactions occur quicker and more powerful with increasing temps

molecules move faster increasing temps raises kinetic energy of molecules

more collisions overcome activations energy increasing the speed and intensity of chemical reactions

coupled reaction

when the energy released from an exergonic reaction I s used to drive an endergonic reaction

EXER ALWAYS FIRST THEN ENDER

Photosynthesis and cellular respiration

coupled reactions

Photosynthesis(endergonic):

6CO2+6H20-> C6H2O6+6O2

Cell res(exergonic):

C6H2O6=6CO2+6h2O+ATP

cyclical reactions and ex

allows for the reaction to continue even without outside resources EX: photosynthesis and cellular respiration

how does breathing help process glucose

Breathing provides oxygen that allows cells to break down glucose during cellular respiration, producing ATP for energy and releasing carbon dioxide and water as waste.

Explain ATP using the photo thingy

Ender reactions cant happen

without exergonic reactions occurring first, they provide energy to drive the endergonic reactions

What energy is used to bond/break phosphate

Glucose! energy from glucose is transferred into phosphate bonds and breaking those phosphate bonds releases energy for the cell

how is cellular energy carried between coupled reactions

energy must be transferred via energy carrier molecules which capture energy from exergonic reactions and deliver it to power endergonic reactions

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