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

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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

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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

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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

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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)

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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

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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+

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Substrate-Level Phosphorylation; transfer of Phosphate group from ADP TO ATP

Location; cytoplasm to mitochondria

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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 image

No oxygen and located in mitochondrial matrix

image 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

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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

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36 to 38 ATP produced from the cell