Chapter 2 Bio Test Brueno

What is an atom?

The smallest unit of matter; made of protons, neutrons, and electrons.

What are protons?

Positively charged particles found in the nucleus of an atoms

What are neutrons?

Particles with no charge found in the nucleus of an atom

What are electrons?

Negatively charged particles that move around the nucleus and determine chemical behavior

What is an element?

A pure substance made of only one type of atom

What is a molecule?

Two or more atoms bonded together

What is a compound?

A substance made of two or more different elements chemically combined

What is an ionic bond?

A bond formed when electrons are transferred between atoms, creating ions

What is a covalent bond?

A bond formed when atoms share electrons

What is polarity?

Unequal sharing of electrons that creates partial positive and negative charges

Why is water polar?

Oxygen attracts electrons more strongly then hydrogen

What is cohesion?

Attraction between molecules of the same substance (water to water)

What is adhesion?

Attraction between molecules of different substances (water sticking to surfaces)

What is a solution?

A mixture in which substances are evenly distibuted

What is a solute?

The substance that is dissolved in a solution

What is a solvent?

The substance that dissolves the solute

What is a suspension?

A mixture where particles do not dissolve and remain floating

What does the pH scale measure?

The concentration of hydrogen ions H⁺

Why is the pH scale not linear?

Each step represents 10x change in acidity or basicity

What are acids and bases?

Acids increase H⁺ ions; bases increase OH^- ions

What are carbohydrates used for?

Quick energy and structural support

What are lipids used for?

Long-term energy, insulation, and cell membranes

What are proteins used for?

Enzymes, structure, transport, defense, and regulation

What are nucleic acids used for?

Store and transmit genetic information (DNA & RNA)

Simple sugar is a subunit of what macromolecule?

Carbohydrates

Amino acids are subunits of what macromolecule?

Proteins

Nucleotides are subunits of what macromolecule?

Nucleic acids

What happens to atoms during a chemical reaction?

Atoms are rearranged but not created nor deystroyed

What must stay the same in a chemical reaction

The number of each type of atom

What is an exothermic reaction?

A reaction that releases energy

What is an endothermic reaction?

A reaction that absorbs energy

What is activation energy?

The energy needed to start a chemical reaction

What is an enzyme?

A protein that speeds up chemical reactions by lowering activation energy

How are catalyst, enzyme, and protein related?

Enzymes are proteins that act as biological catalysts