Chapter 2 The Chemistry of Life-1-1-1

What is the simplest type of matter with unique chemical properties?

Element

What are the three subatomic particles of an atom?

Proton, neutron, electron

What is an isotope?

Forms of the same element with the same number of protons and electrons but a different number of neutrons.

Define an anion.

An atom that gains electrons and has a net negative charge.

What is a cation?

An atom that loses electrons and has a net positive charge.

What is an electrolyte?

Salts that ionize in water and form solutions capable of conducting an electric current.

Differentiate between a molecule and a compound.

A molecule is composed of two or more atoms united by a chemical bond, while a compound is composed of two or more different types of atoms chemically combined.

What are the four classes of macromolecules?

Carbohydrates, lipids, nucleic acids, and proteins.

What type of bond is formed by the sharing of one or more pairs of electrons?

Covalent bond.

Define a hydrogen bond.

A weak attraction between a slightly positive hydrogen atom of one molecule and a slightly negative atom (such as oxygen or nitrogen) of another molecule.

What is the Octet Rule?

Main group elements tend to bond so that each atom has eight electrons in its valence shell.

What is the role of water in biological systems?

Water acts as a solvent, regulates temperature, participates in chemical reactions, and serves as a lubricant and cushion.

What is metabolism?

The sum of all chemical reactions occurring in the body, including anabolism and catabolism.

What are the main functions of proteins?

Structure, transport, protection, communication, and catalysis (enzymes).

What distinguishes RNA from DNA?

RNA contains ribose sugar, is single-stranded, and has uracil instead of thymine.

What is ATP?

Adenosine triphosphate, the main energy currency of the cell.

What happens during hydrolysis?

A polymer is split by the addition of a water molecule.

Define dehydration synthesis.

The process where monomers covalently bond together to form a polymer with the removal of a water molecule.

What is the significance of the pH scale in biological systems?

It measures hydrogen ion concentration, which affects physiological functions. A neutral pH is 7, with physiological pH around 7.4.

What is a buffer?

A solution of an acid-base pair that minimizes changes in pH by accepting or donating hydrogen ions.

Name the six elements that account for 98.5% of the body's weight.

Carbon, hydrogen, oxygen, nitrogen, phosphorus, calcium.

What is a covalent bond characterized by?

The sharing of electrons between atoms.

What effect does a catalyst have on a chemical reaction?

It speeds up the reaction without being permanently changed.

How do isotopes differ in terms of atomic mass?

Isotopes have different atomic masses due to varying numbers of neutrons.

What do we call the reactions that build larger molecules from smaller ones?

Synthesis reactions.

What are the two types of energy-related reactions?

Exergonic (release energy) and endergonic (consume energy).