Bio Chap 2

What is matter?

Anything that takes up space and has mass.

What are elements?

Substances that cannot be broken down into simpler substances by chemical reactions.

What are compounds?

Substances formed when elements combine in fixed ratios, possessing distinct properties from their constituent elements.

What is the atomic number?

The number of protons in an atom's nucleus.

What is the mass number?

The sum of protons and neutrons in an atom's nucleus.

What are isotopes?

Atoms of the same element that have the same number of protons but different numbers of neutrons.

What is a cation?

An atom that loses an electron and becomes positively charged.

What is an anion?

An atom that gains an electron and becomes negatively charged.

What distinguishes ionic bonds from covalent bonds?

Ionic bonds involve the transfer of electrons, while covalent bonds involve sharing electrons.

What are weak chemical interactions?

Interactions such as hydrogen bonds and van der Waals interactions that are vital in biological systems.

What is the significance of electronegativity in chemical bonds?

It determines an atom's ability to attract electrons in a covalent bond.

What are hydrogen bonds?

Attractions between a hydrogen atom covalently linked to an electronegative atom and another electronegative atom.

How do van der Waals interactions occur?

Through temporary fluctuations in electron distribution creating fleeting positive and negative charges.

What role does molecular shape play?

It influences how biological molecules recognize and interact with each other.

What is molecular mimicry?

A phenomenon where molecules with similar shapes can bind to the same receptors and elicit similar effects.

What are reactants in a chemical reaction?

The starting materials involved in a chemical reaction.

What are products in a chemical reaction?

The substances formed as a result of a chemical reaction.

What process do plants use to convert carbon dioxide and water into glucose?

Photosynthesis.

What does it mean when chemical reactions are reversible?

They can proceed in both the forward and reverse directions and can reach equilibrium.

What is chemical equilibrium?

A state where the forward and reverse reactions occur at the same rate, leading to stable concentrations of reactants and products.

What are protons?

Subatomic particles with a positive charge found in the nucleus of an atom.

What are neutrons?

Subatomic particles with no charge that are located in the nucleus of an atom.

What are electrons?

Subatomic particles with a negative charge that orbit the nucleus of an atom.

What is atomic mass?

The weighted average mass of the naturally occurring isotopes of an element.

What are covalent bonds?

Bonds formed when two atoms share one or more pairs of valence electrons.

What is a polar covalent bond?

A bond formed when electrons are shared unequally between atoms with different electronegativities.

What is non-polar covalent bond?

A bond where electrons are shared equally between atoms with similar electronegativities.

What is a compound's property distinction?

Compounds have different properties than their constituent elements.

What is an example of a compound?

Table salt (NaCl), which has different properties than sodium and chlorine.

How do ionic compounds form?

Through the attraction between cations and anions that arrange themselves in a three-dimensional lattice.

What are radioactive isotopes used for?

As diagnostic tools in medicine and for dating fossils and rocks.

What do weak chemical interactions influence in biological systems?

The three-dimensional shapes and interactions of molecules.

Why is molecular shape critical in biology?

It affects biological activity and how molecules interact.

How does photosynthesis exemplify chemical reactions?

It showcases the rearrangement of atoms to create new molecules, specifically glucose and oxygen.

What signifies the importance of chemical bonds?

They are foundational for the structure and function of molecules essential for life.