Energy- the ^^ability to work or cause change^^ (chemical reactions)
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There are 2 types:
^^Energy stored^^, causes change in the ^^future^^.
^^Energy of motion^^ causing change ^^now^^.
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Free Energy(G)- ^^energy that is converted into a useful form^^ (released OR stored). ^^Available energy^^ in a system.
Entropy(S)- ^^energy that is lost as non-useful heat^^
Enthalpy(H)- ^^total energy^^ in a system
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1st Law of Thermodynamics:
^^Energy cannot be created or destroyed, only converted^^ from one form to another.
2nd Law of Thermodynamics:
^^Energy is loss during transformation^^. As energy is converted, entropy increases until no energy is left to do work.
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Bioenergetics- the ^^study of energy transfer^^ in the cell
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2 Types of Metabolism
Degradation/^^breakdown of biological molecules so energy is released.^^ Therefore it is ^^exergonic^^ and tend to be ^^oxidation^^. Eg. Cell Respiration.
The ^^build up of biological molecules so energy is stored^^. Therefore it is ^^endergonic^^ and tends to be ^^reduction^^. Eg. Photosynthesis.
Energy Input is needed for Anabolism.
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Simple Oxidation - a ^^one step chemical reaction that requires high temperature and releases large amounts of heat.^^
Body Cells cannot do simply oxidation.
^^Body cells use oxidative phosphorylation^^. It is a controlled oxidation. A ^^series of reactions.^^
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Main goals:
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Cell Respiration occurs in 25-30 steps.
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It occurs in 4 steps:
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Where? In the ^^cytoplasm^^.
What does it start with? ^^Glucose^^
What does it produce?
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Summary of Glycolysis:
^^2 ATP used to prepare 6C glucose for splitting into two 3C^^ molecules. Substrate level phosphorylation is used.
^^6C glucose splits into two 3C molecules.^^
^^G3P is oxidated. It releases H+ and e- which are captured by NAD+→NADH^^. NADH moves on to the ETC.
^^ATP is produced by removing the phosphates and producing 2 pyruvates (3C).^^
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Where? In the ^^matrix of the mitochondria.^^
What does it start with? ^^2 pyruvates^^.
What does it produce?(per cycle)
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Summary of Pyruvate Oxidation:
^^Pyruvate enters the mitochondria^^ from the cytoplasm.
^^One carbon is removed with a release of CO2.^^
^^Hydrogen is removed by NAD+→NADH.^^
^^A CoA (coenzyme) becomes attached^^ to the remaining carbons which ^^creates Acetyl CoA.^^
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Where? In the ^^matrix of the mitochondria.^^
What does it start with? ^^Oxoloacetate (OAA) and Acetyl CoA^^
What does it produce? (Per cycle)
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Summary of Krebs Cycle:
An ^^Acetyl CoA(2C) molecule joins a Oxaloacetate(4C) molecule to produce Citrate(6C).^^
^^Isocitrate(6C) is oxidized into an Alpha-ketogluterate(5C) and then into Succenyl CoA(4C)^^ while ^^producing 2 NADH and 2 CO2.^^ All original carbons have been released at this point.
^^Succenyl CoA(4C) is converted into succinate(4C) while producing an ATP and losing a CoA.^^
^^Succinate(4C) converts to Fumerate(4C) and makes FADH2^^
^^Fumerate(4C) is converted into Malate(4C) and then is converted back into Oxaloacetate(4C) while producing NADH.^^
Where? In the ^^cristae folds, the matrix and the inner membrane space of the mitochondria.^^
What does it start with? ^^NADH and FADH^^
What does it produce? ^^36-38 ATP^^
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Summary of the ETC+C:
^^NADH is oxidized in the matrix. High energy e- are released into the ETC.^^
^^e- from NADH moves down ETC and use energy to pump H+ ions across the membrane^^. (3 pumps)
After the third pump the ^^e- is accepted by oxygen to form H2O.^^ This ^^allows for more e- to flow^^ down the chain.
(CHEMIOSMOSIS).The ^^high [H+] in the inner membrane are moved through ATP synthesis back into the matrix, low [H+]. This movement creates the energy needed to form ATP from ADP and Pi.^^
Note: FADH produces 2 ATP because it only goes through 3 pumps whereas NADH produces 3 because it travels through all 3 pumps.
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Remember: NADH creates 3ATP, FADH creates 4ATP
Glycolysis:
^^Total: 6-8 ATP^^
Pyruvate and Krebs Cycle:
^^Total: 30 ATP^^
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What do we use the ATP for?
^^ATP is used immediately^^ to do things like; ^^make protein, muscle fibrils contractions, DNA+RNA assembly, nerve impulse trahissions, active transport and chemical reaction activation.^^
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The Final Equation:
C6H12O6 + 6O2 + 6H2O → 6CO2 + 12H2O + 36-38 ATP + Heat
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What happens when no O2 is present?
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Alcohol fermentation in yeast
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Lactic acid fermentation in muscle cells:
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Energy from proteins:
Eg. Alanine (amino acid)
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Energy from fats:
Eg. Triglycerides
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How does 6C F.A produce 44ATP?
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Overall Results:
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Light is converted into glucose in approximately 2 minutes after the leaf is exposed to light.
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6CO2 + 12H2O → light → C6H12O6 + 6O2 + 6H2O
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Co2: in through %%stomata%% (gas exchange)
H2O: %%roots, xylem%% (water transport cells)
Glucose: %%CO2 combined H+%% ions from water
O2: from %%water%%
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Thylakoid: %%pigment molecules in bilayer. Traps light.%%
Stroma: %%enzymes for making glucose%%. %%Ribosomes for making proteins/enzymes. DNA that can duplicate on their own.%%
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Thylakoid Membrane:
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Photosystem:
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Chlorophyll:
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%%Both A and B chlorophyll are embedded in the thylakoid bilipid layer by the phytol tail%% being buried inside. The %%phytol tail is hydrophobic and the porphyrin ring is hydrophilic.%%
Both types absorb red and blue-violet light, they reflect green wavelengths.
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%%Many double bonds alternate with single bonds. This allows the molecules to absorb light.%% It %%allows extra electrons of the double bonds to be excited%% when light photons hit them. This %%occurs in the porphyrin ring.%%
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Chlorophyll A:
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Chlorophyll B:
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There is normally 3x more chlorophyll A than B.
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Light dependant summary:
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Calvin Cycle summary:
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Noncyclic: electron flow generates a proton gradient for chemiosmotic ATP synthesis and NADPH. Normal light reaction.
Cyclic: e- excited in PS1 are taken back to the B6F complex by ferridoxin to pump H+ ions across the membrane. These ions can then be used to make ATP. PC recycles the e- back to PS1 and the cycle can continue.
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Light energy transfers through the upper cuticle.
H2O transported by veins.
CO2 enters through lower cuticle/stomata
O2 leaves through lower cuticle/stomata
H2O(some) diffuses through lower cuticle/stomata
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Photorespiration
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C3, normal plants.
C4 Pathway (Hot/dry/tropical)
Uses Z locations
uses special enzymes that only reacts with CO2. Pepcarboxylose.
CAM plants (cactus)
Uses different times of day.
At night, the stomata opens, CO2 diffuses into plant.
During the day, stomata closes and light reactions occur and create energy for Calvin cycle.
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How can we measure the rate of photosynthesis?
Net CO2 uptake= CO2 taken in during photosynthesis - CO2 released during during mito respiration - CO2 released into a plant during photorespiration.
The Leaf and Photosynthesis
Anatomy of a leaf diagram. https://www.enchantedlearning.com/subjects/plants/leaf/
Alternative Pathways
C4 pathway diagram. https://biodifferences.com/difference-between-c3-c4-and-cam-pathway.html
CAM pathway diagram. https://www.botanicacuriosa.com/blog/crassulacean-acid-metabolism-cam-the-other-photosynthesis
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