Chapter 1: The Chemical Basis of Life Flashcards Preview

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Flashcards in Chapter 1: The Chemical Basis of Life Deck (88)
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1

Isotopes

Different atoms of the same element containing the same number of protons but a different number of neutrons.

2

Radioisotopes

Radioactive atoms of an element that spontaneously decay into smaller atoms, subatomic particles, and energy.

3

Half-Life

The time it takes for one-half of the nuclei in a radioactive sample to decay.

4

Radioactive Tracers

Radioisotopes that are used to follow chemicals through chemical reactions and trace their path as they move through the cells and bodies of organisms

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Orbitals

Volumes of space around the nucleus where electrons are most likely to be found.

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Valence Electrons

Electrons located in outermost s and p orbitals that determine an atom's chemical behavior.

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Intramolecular Forces of Attraction

The covalent bond that holds the atoms of a molecule together, and the ionic bond that holds ions together in a salt.

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Electronegativity

A measure of an atom's ability to attract a shared electron pair when it is participating in a covalent bond.

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Hybridization

For atoms, a modification of the valence orbitals that changes the orientation of the valence electrons; in genetic coding, complementary base pairing between strands of nucleic acids via hydrogen bonding.

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Intermolecular Bonds

Chemical bonds between molecules.

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Van der Waals Forces

Intermolecular forces of attraction including London Forces, dipole-dipole forces and hydrogen bonds.

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Miscible

Describes liquids that dissolve into one another.

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Immiscible

Describes liquids that form separate liquids instead of dissolving.

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Hydrophobic

Having an aversion to water; the tendancy of nonpolar molecules to exclude water.

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Hydrophilic

Having an affinity to water; the tendency of polar and ionic substances to dissolve in water.

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Neutralization Reaction

The reaction of an acid and a base to produce water and salt.

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Strong Acids

Acids that ionize completely in aqueous solution.

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Strong Bases

Bases that ionize completely in aqueous solution.

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Weak Acids

Acids that partially ionize in aqueous solution.

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Weak Bases

Bases that partially ionize in aqueous solution.

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Equilibrium

A condition in which opposing reactions occur at equal rates.

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Buffers

Chemical systems containing a substance that can donate H+ ions when they are required and containing a substance that can remove H+ ions when there are too many in a solution.

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Activation Energy

The difference between the energy level of the transition state and the potential energy of reacting molecules.

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Activator

A substance that binds to an allosteric site on an enzyme and stabilizes the protein conformation that keeps all the active site available to their substrates.

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Active Site

The location where the substrate binds to an enzyme.

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Adenosine Triphosphate (ATP)

A nucleotide derivative that acts as the primary energy-transferring molecule in living organisms.

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Allosteric Inhibitor

A substance that binds to an allosteric site on an enzyme and stabilizes the inactive form of the enzyme.

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Allosteric Sites

Receptor sites, some distance from the active site of certain enzymes, that bind substances that may inhibit or stimulate an enzyme’s activity.

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Alpha (α) Helix

A type of polypeptide secondary structure characterized by a tight coil that is stabilized by hydrogen bonds.

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Amino Terminus

The free amino group at one end of a polypeptide.