Biology Mcgraw Hill 6

Oxidation

- An atom or molecule that loses an electron

Kinetic Energy

Energy of motion

Potential Energy

Stored energy

Thermodynamics

Heat and temperature and their relation to energy and work

Redox

- Oxidation states of atoms are changed through transfer of electrons between chemical species

First Law of Thermodynamics

- Energy cannot be created or destroyed

• Heat can be harnessed when there is a temperature difference between two areas

• Chemical potential Energy can be shifted to a similar form

Heat

- Measure of the random motion of molecules

Entropy

- Unavailability of thermal energy for conversion into mechanical work

Enthalpy

- Equivalent to the total heat content of a system

Free Energym

- Energy available to do work in any system

Endergonic

- Energy into a reactant

Exergonic

- Energy out of a reactant; spontaneous

Activation Energy

- Minimum amount of energy the reacting species just possess to undergo a reaction

Catalysis

- Process of influencing chemical bonds to lower activation energy needed to initiate a reaction

Inorganic Phosphate

- Inorganic chemical and a salt of phosphoric acid; ester of phosphoric acid

Substrate - Substance or layer that underlies something, or on which some process occurs

Active Site

- Region on an enzyme that binds to a protein or other substance during a reaction

Enzyme-Substrate Complex

- Intermediate formed when a substrate molecule interacts with active site of the enzyme

Multi-Enzyme Complex

- Stable assemblies of more than one enzyme, generally involved in catalytic transformations

Inhibitor

• gene whose presence prevents expression of some other gene

• Substance slows or prevents chemical reaction

Competitive Inhibitor

- Active site of enzyme prevents binding of substrate

Noncompetitive Inhibitor

• Binds any where other than the active site

• Reduces activity of the enzyme and binds well whether or not it's already bound to the substrate

Allosteric Site

- Small, regulatory molecule interacts with an enzyme to activate specific enzyme

Allosteric Inhibitor

- Binds to enzyme at a location other than the active site

Allosteric Activator

- Binding enhances attraction between substrate molecules

Coenzyme

- Non-protein compound that is necessary for functioning of an enzyme

Biochemical Pathways

- Long chains of chemical reactions

Feedback Inhibition

- Enzyme catalyzes production of substance when at a certain level

autotrophs

An organism that obtains organic food molecules without eating other organisms or substances derived from other organisms; use energy from the sun or from the oxidation of inorganic substances to make organic molecules from inorganic ones.

heterotrophs

Organisms that can not obain energy from manufacturing their own food, so they obtain their energy from others

cellular respiration

the process by which energy is harvested; the oxidation of organic compounds to extract energy from chemical bonds

dehydrogenation

Chemical reaction involving the loss of a hydrogen atom. This is an oxidation that combines loss of an electron with loss of a proton.

NAD+

Nicotinamide adenine dinucleotide, a cofactor present in all cells that helps enzymes transfer electrons during the redox reactions of metabolism.

NADH

The reduced form of NAD+ (nicotinamide adenine dinucleotide). This is the most common electron carrier in cellular respiration.

aerobic respiration

when the final electron acceptor is oxygen during cellular respiration

anaerobic respiration

when the final electron acceptor during cellular respiration is an inorganic molecule other than oxygen

fermentation

when the final electron acceptor during cellular respiration is an organic molecule

electron transport chain

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.

substrate level phosphorylation

ATP is formed by transferring a phosphate group directly to ADP from a phosphate

2

the synthesis of ATP can be accomplished by __ fundamentally different mechanisms

oxidative phosphorylation

Part of the electron transport chain. A process occurring in the mitochondria that results in the formation of ATP from the flow of electrons across the inner membrane to bind with oxygen and H+ ions. Accounts for most of the ATP generated by respiration.

1. Glycolysis
2. Pyruvate oxidation
3. Krebs cycle
4. Electron transport chain & chemiosmosis

the 4 stages of the complete oxidation of glucose

2

Carbon Acetyl Group

NADH

The Krebs cycle itself does not produce a large amount of ATP, but it does produce a large amount of ______, which can transfer electrons to the electron transport chain

NADH FADH2

The nine reacitons of the Krebs Cycle take in 2

Condensation

Reaction 1 in the Krebs Cycle. Citrate is formed by joining acetyl

High

____ ATP concentration results in Condensation not taking place

Isomerization

Reactions 2 and 3. The repositioning of the hydroxly (OH

1st Oxidation

Reaction 4. Isocrite undergoes and oxidative decarboxylation reaction. NADH and CO2 produced. Forms alpha ketoglutarate

2nd Oxidation

Reaction 5. Alpha Ketoglutarate is decarboxylated producing NADH and CO2. Forms Succinyl

Substrate

Level Phosphorylation

3rd oxidation

Reaction 7. The free energy change in this reaction is not enough to reduce NAD+, so FAD becomes the electron acceptor making FADH2. Forms Fumurate

Regeneration of Oxaloacetate

Reaction 8 and 9. A water molecule is added forming Malate, which is then oxidized to produce an NADH molecule. Forms oxaloacetate and the Krebs cycle is ready to repeat again.

CO2

In the process of aerobic respiration, glucose is entirely consumed. all the C is eventually lost throughout glycolysis and the Krebs Cycle as _____

NADH dehydrogenase

the first of the proteins to receive electrons from the electron transport chain is a complex membrane embedded enzyme called this.

mitochondria

cellular respiration takes place within this organelle in virtually all eukaryotic cells

Chemiosmosis

uses a proton gradient to make ATP

ATP synthase

molecular mechanism that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP

Phosphofructokinase

In feedback inhibition in glycolysis ______________________
is allosterically inhibited by ATP and/or citrate

Pyruvate dehydrogenase, Citrate synthetase

In pyruvate oxidation _________ ____________ is inhibited by high levels of NADH. _________ ____________ is inhibited by high levels of ATP.

ethanol fermenation

occurs in yeast, CO2, ethanol, and NAD+ are produced

lactic acid fermentation

occurs in animal cells. Electrons are transferred from NAHD to pyruvate.

deamination

the nitrogen containing side group (the amino group) is removed from each amino acid in this process

acetyl groups

the process of beta oxidation of fatty acids produces these