Ch 9
Ch 8
Bioenergetics; study of energy flow through living organisms
Metabolism; orderly interactions between molecules
Free Energy - Change of free energy
Metabolic pathways' start with specific molecule, altered in different steps for specific product
Manages material & enery resource of cell
Catabolic pathways (breaks down complex molecules)
Anabolic pathways (consumes molecules to make more complex molecules
Ex. Cellular respiration; glucose & organic fuels broken down when oxygen to carbon dioxide and water
Ex. Synthesis of protein from amino acid
Energy; Capacity to cause to change
Potential energy; not moving may still posses energy b/c location & structure
Kinetic energy; Moving object can perform work by imparting motion to other matter
Thermal energy (kin assoc) Random movement of atoms or molecules
Heat; the transfer of thermal energy from one object to another
Light energy uses photosynthesis in green plant
Chemical energy; potential energy available for release in a chemical reaction
Thermodynamic; energy transformation occur in a collection of matter
1st Law/ Principle of conservation of energy
Energy can be transferred & transformed, but it cannot be created or destroyed
Ex. Electrical companies do not create electricity but convert energy for our use
2nd Law
"Every energy transfer or transformation increases the entropy of the universe"
Entropy; measurement of molecular disorder (increases organization over time)
Reason why organism cannot recycle energy b/c every transfer or transformation some energy becomes unavailable for work and increases entropy
Form of increasing amount of heat & less ordered form of matter
Spontaneous process; Increases entropy doesn't require input of energy
Non-Spontaneous; happens only if energy is supplied (decrease entropy)
Free energy; part of system only does work if temperature & pressure are uniform throughout the system
Free energy changes when system changes
Change of G = G final state- G initial state
Measure of a system's instability; tendency to change & be role stable
Exergonic (energy outward)
Endergonic (energy inward)
Release of free energy b/c chem mixture loose energy (G decreases) ΔG is negative
Spontaneous
Absorbs energy from surroundings
Stores free energy in molecules (G increase)
ΔG is positive & non spontaneous
ΔG magnitude is the quantity of energy drive reaction (uphill)
ATP powers cellular work by coupling excergonic reactions to endergonic reaction
Cells
3 kinds of work cell do
Transport work (pumping substances across membrane; spontaneous)
Mechanical work (contraction of muscle cells)
Chemical work (using endergonic reactions that would not occur spontaneously
Resources of energy managed to do work by
Energy coupling; use exergonic process to drive endergonic
ATP responsible modifying most energy
Cellular respiration
Hydrolysis breaks down bonds by adding a water molecule
Release 7.3 Kcal /mol (-35.5KJ)
Cell's protein use energy released by ATP hydrolysis to perform cellular work; Chemical, transport, and mechanical.
Transport and mechanical work in cell usually powered by ATP hydrolysis
Mechanical involved motor protein along cytoskeleton elements, happens in ATP bond noncovantly to motor protein. Next ATP hydroysis releases ADP & P1. Another molecule can bind each stage changes shape and ability to bind cytoskeleton track
ATP binds noncovalent to motor proteins & then is hydrolyzed causing change that walks motor protein forward
ATP phosphorylation transport proteins, causing a shape change that allows transportation of solutes
Enzymes; Is a macromolecule acts as a catalyst, chemical agent that speeds up reaction without being consume
ATP is renewable resource can be regenerated by adding phosphate to ADP
Energy required to bind P to ADP+ Free energy --> ATP+ H2O
Comes from Exergonic reaction which coupling of endergonic reactions
For bonds to change reactants must absorb energy from surroundings
Activation energy; energy required to contort the reactants molecules to bonds can break
Provides a barrier to determine rate of reaction
Reactants absorb enough energy enough to reach top of barrier reactions occur
Difficult to reach & doesn't enter transition state
Passes barrier transition state; molecules become unstable
1st.Glycolysis; breaking down of glucose by enzyme, releasing energy and pyruvic acid.
2nd Transition reaction (no need of oxygen)
3rd Citric acid/Krebs cycle
4th Electron transport system
Can occur with oxygen and without oxygen
no-oxygen (Anaerobic) = fermentation in humans produces lactic acid but other organisms (yeast) produce ethanol or alcohol
Oxygen (Aerobic)
Breaking glucose into 2 pyruvate molecules; each is 3 carbon molecules
Net of 2 ATP; using 2 to be able to double it to 4 ATP= net +2
Reduction NAD to NADH (gaining electrons)
NAD+ gains an 2 electron and a hydrogen proton when becoming NADH
Or negativity charged hydrogen atom
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location; Cytoplasm near mitochondria
Reactants and products
Reactants; 1 glucose, 2NAD+ from Electron transport system, 2ADP + 2 P
Products; 2ATP, 2 pyruvic acid, 2NADH go to Electron transport system, and 2H+
Substrate-Level Phosphorylation; transfer of Phosphate group from ADP TO ATP
Location; cytoplasm to mitochondria
Reactants and products
reactants; 2 pyruvic acid, 2 NAD+ from Electron transport system, 2 coenzymes A
Products; 2CO2, 2NADH-go to Electron transport system, 2 Acetyl CoA
Glycolysis to transition reaction
No oxygen and located in mitochondrial matrix
Happens twice for each glucose molecule
Reactants and products
Reactants;2 Acetyl CoA
6 NAD+ from ETS
2 ADP + 2P
2 FAD from ETS
Products: 4CO2, 6NADH go to ETS, 2FADH2 go to ETS, ATP
REQUIRES OXYGEN! and located in inner mitochondrial membrane
Reactants and products
Chemiosmosis in mitochondrion
Oxidative Phosphorylation
Reactants; 10 NADH, 2 FADH2, O2, H+, ADP,P
Products; H2O, 32 OR 34 ATP, NAD+, FAD
Most ATP made, happens in Cristae of mitochondrian, NEEDS OXYGEN
Oxidative b/c oxygen as terminal electron acceptor
P from molecule of ATP from phosphorylation to ATP
Electron carriers transport electrons to co-enzymes; then transported down ETC releases energy; the energy is used to transform ADP + P to ATP
Last acceptor is for oxygen electrons; oxygen removes the hydrogen and electrons, making water
36 to 38 ATP produced from the cell