Le Chatelier's principle

Le Chatelier's principle

Le Chatelier's principle states that when any change is made to the conditions of an equilibrium the position of the equilibrium moves in the direction that minimises the change. Some reactions are reversible in dynamic equilibrium the rate of forward (right) reaction is the same as the backward (left) reaction concentrations of products and reactants stay the same and dynamic equilibrium can only happen in a closed system Can be any combination of reactants and products, doesn’t have to be half and half and effects of changes in conditions predicted by Le Chatelier’s principle.

  “If a system at equilibrium is disturbed, the equilibrium moves in the direction that tends to reduce that disturbance”

Rate of forward or backward reaction increases to minimise change both forward and reverse rates are speeded up equally and No effect on the yield . We get no more product, we just get it faster. Industrial equilibrium use compromise conditions that balance yield against reaction rate, cost and risks of equipment needed for conditions, side reactions and catalysts. Ammonia, ethanol and methanol are all produced industrially using a compromise temperature and pressure

The table below shows some of the properties that occur when Le chatelier's principle is in use: 

The equilibrium constant is the ratio of product concentration to reactant concentration which is raised to its appropriate power. this only varies for a reaction when the temperature is changed and it indicates whether the position of equilibrium to the left or to the right.

The equilibrium constant formula is: 

In industry a compromise may be needed between yield and rate  such as for exothermic reaction, a lower temperate gives you a higher yield and a lower temperature saves costs in terms of no need to pay for electricity to create heat or fuel on the other hand a lower temperature slows down the forward backward reactions so it would take longer to reach equilibrium.

**REMEMBER TO STAY POSITIVE LIKE A PROTON!!**

Lung Function

Lung Function

Measurements of lung function tend to be made using two pieces of equipment called a peak flow meter and/or a spirometer.

A peak flow meter measures the rate at which a patient expel air into a handheld tube, this can be used to monitor conditions such as asthma.

A spirometer is where patients breathe in and out of a mouthpiece attached to a sealed chamber where oxygen from the chamber is used up this can be used to measure many different lung components when a pencil attached to a rotating drum can create a trace on a spirometry graph paper.

Total lung capacity: Vital capacity + residual volume

Residual volume: is the volume remaining in the lungs even after a person has exhaled with maximum force.

Vital capacity: is the maximum volume that can be breathed out following the strongest possible inhalation (i.e. tidal volume + inspiratory reserve volume + expiratory reserve volume)

Tidal Volume: is the volume inhaled with each resting breath (or the volume exhaled with each resting breath)

Inspiratory and expiratory reserve volumes are the additional volumes of air that can be breathed in and out during forced inhalation and exhalation.

vital capacity can potentially be defined and measured in two ways it can either the maximum volume of air exhaled following the strongest possible inhalation or the maximum volume inhaled following the strongest possible exhalation and both values should be the same.

Breathing rate=The number of breath per minute.

Ventilation rate= The total volume inhaled per minute=Breathing rate X Tidal volume

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Electron Transport Chain

The electron transport chain

The electron transport chain is located on the inner mitochondrial membranes. The chains use energy from electrons to pump H+ ions into the intermembrane space. A proton gradient is established which enables chemiosmosis to occur through ATP synthasae. The sequence of events is as follows:

Most of the ATP generated  in respiration is produced via oxidative phosphorylation. The reduced coenzymes  FADH2 and NADH produced during the earlier stages of respiration such as glycolysis donate H+ ions and electrons to an electron transport chain and ATP is synthesised.

There are 5 complex called :

Complex 1-NADH Dehydrogenase

Complex 2-Succinate Dehydrogenase

Complex 3-Cytochrome C reudctase

Complex 4-Cytochrome C oxidase (a-a3 Complex)

Complex 5-F0-F1

Mobile carriers:

Q= Ubiquinone

Cyt C=Cytochrome C 

Let's talk about NADH the first product made from  glycolysis. It transfers h+ and E- electrons into Complex 1 to Q a mobile carrier and then to complex 3 to Cyt C another mobile carrier to complex 4 where the electron is accepted by oxygen with hydrogen to make water. All this movement from the electron carriers complexes have created energy this energy is used to pump hydrogen ions into the intermembrane space which create a proton gradient this then means that H+ ions can enter back into the matrix this is done by complex 5 and this then causes ADP to hydrolysis with Phosphate to create ATP.

For every 2H+ion 1 ATP is created

altogether the 6 H+ ions creates 3 ATP

Now let's talk about the second product used from glycolysis called FADH2, it takes a slightly different pathway. FADH2 is oxidised to FAD+ in complex 2 and enter Q mobile carrier where electrons travel to complex 3 and then to Cyt C mobile carrier and then to complex 4 where electrons get accepted to oxygen and hydrogen to produce water, H+ ions pump from complex 3 and complex 4 and this creates a proton gradient where H+ ions enter back via complex 5 which creates ATP.

-4H+ ions can produce 2 ATP

Overall this how much energy is created from oxidative phospohorylation:

	ATP	NADH/FADH2	ECT ATP produced
Glycolysis	4	2 NADH	6
Link Reaction	------	2 NADH	6
TCA Cycle	2	6 NADH 2 FADH	18 4
Total:	6		34

Total: 6+34=40 ATP

*Net gain ATP: 40-2=38

*Hint: 2 ATP was used in the beginning of glycolysis.*

**REMEMBER TO STAY POSITIVE LIKE A PROTON**

Cholesterol

Cholesterol

Fatty acids are in all lipids expect cholesterol.

Cholesterol forms a hydrophobic layer of about 12-20 atoms the optimal belayed has about 6-8nm thickness.

Examples in organisms:

Palmite (16) + sterate (18) unsaturated carbon atoms.

1 double bond                      2 double bond

Linoleate (18) and 3 double bonds, Arcahedonate (20) has 4 double bonds.

Unsaturated fatty acids in membranes are in cis creating beds and kinks so do not pack tightly in membrane. 

Movement of phospholipids within membranes.

-Rotation

-Lateral diffusion

-Transverse diffusion (flip-flop): this is where one monolayer to another and is done by proteins in ER called phospholipids translocations and flippases enzymes.

Lipid membrane is fluid which allows lateral diffusion and move faster than proteins are smaller and weigh less.

Florescence recovery after photo bleaching

1-unlabbled cell surface

2-cell surface molecules labelled with fluoresce dye

3-laser beam bleaches an area of cell surface

4-Florucescent labelled molecules diffuse into bleached area.

Dye creates covalent bond to living cell.

-->Uses a high intensity laser beam

-->Rate of diffusion florescence into bleached area measured over time.

Temperature changes fluidity:

transition temperature (Tm)= Temperature when it melts

Phase transition= Membrane changes state.

Differential scanning calorimetery

-''n''' shaped curve

-Peak is the Tm

-More saturated the higher temperature

saturated fatty acids fit more tightly packed as there are no bends.

Determining fluidity:

-length of fatty acid chains (long chains higher temperature) less fluid.

-Degree of unstauration

Some more in depth information into cholesterol:

-Sterols affect membrane fluidity

-PH group that is polar and everything else hydrophobic

-forms hydrogen bond

-Rigid hydrophobic steroid rings and hydrocarbon chain part interact with adjacent hydrocarbon chain that are adjacent to closest phospholipids head group.

-Plant cholesterol is phytosterols

-Sterol is hopanoids in prokaryotes

-Decrease membrane fluidility above Tm

-Increase membrane fluidilty below Tm

Sterols decrease permeability of lipid bilayer of ions and smaller polar molecules

Pilikotherms (cold blooded animals) cannot regulate own temperature as lipid fluidity decreases as temperature falls membrane would gel. Homotherms (warm blooded) animals compensating effects such as when cold and when you can't feel fingers and toes as sensory never ending stop. When very hot pilikiotherms membranes get very fluid and denature homeoviscous adaptation also is the regulation of membrane fluidility.

Lipid rafts are newly discovered and are localised regions of membrane lipid that are involved in cell signalling. 

**REMEMBER TO STAY POSITIVE LIKE A PROTON!**