Biochemistry Unit 2: Atoms, Bonds, Water, and Biomolecules

What are the three main subatomic particles that make up an atom?

Protons, neutrons, and electrons.

What charge does a proton carry?

A proton carries a positive charge.

Where are protons located in an atom?

Protons are found in the nucleus.

What is the charge of a neutron?

Neutrons have no charge (neutral).

Where can electrons be found in an atom?

Electrons are found orbiting the nucleus.

What determines the atomic number of an element?

The atomic number is determined by the number of protons in the nucleus.

What is an isotope?

Isotopes are atoms of the same element with different numbers of neutrons.

How does the number of neutrons in an isotope affect its properties?

It alters the atom's mass but not its chemical properties.

What is the chemical formula for water?

H₂O.

What is a molecule?

The smallest particle of a substance that has all of the physical and chemical properties of that substance.

Define a compound.

A compound is two or more different elements chemically combined in fixed amounts.

What are chemical bonds?

Forces holding atoms together in compounds, formed by interactions of electrons.

What is an ionic bond?

An ionic bond is formed when atoms transfer electrons, resulting in charged ions.

What is a covalent bond?

A covalent bond is formed when atoms share electrons.

What is a hydrogen bond?

A weak chemical bond formed between a hydrogen atom and an electronegative atom.

What is cohesion in relation to water?

Cohesion is the attraction between particles of the same substance, causing surface tension.

What is adhesion?

Adhesion is the attraction between two different substances.

What is capillary action?

The process where water is attracted to and pulled in a tube, important for plant transpiration.

Why is water considered a universal solvent?

Water can dissolve any substance with a positive or negative charge.

What is the equation for the dissociation of water?

H₂O → H⁺ + OH⁻.

What are the five important properties of water for life?

Cohesion, adhesion, high specific heat, high heat of vaporization, and less dense as a solid.

What happens to water when it freezes?

Water becomes less dense as a solid, allowing ice to float.

What is the significance of water's high specific heat?

It helps regulate temperature in organisms and environments.

What does the pH scale measure?

The concentration of H+ ions.

What is the range of the pH scale?

0 to 14, where 7 is neutral.

What characterizes acids on the pH scale?

Acids have a pH less than 7 and produce H+ ions.

What characterizes bases on the pH scale?

Bases have a pH greater than 7 and contain OH- ions.

What is the significance of each pH unit change?

Each pH unit represents a tenfold change in H+ ion concentration.

What are buffers?

Substances produced by the body to neutralize acids and bases to maintain homeostasis.

What is the basic structure of carbon compounds?

Carbon atoms can form four bonds and can be arranged in chains, branches, or rings.

What are macromolecules?

Giant organic molecules made up of carbon and hydrogen, which can include other elements.

What are the four classes of organic molecules?

Carbohydrates, Proteins, Lipids, Nucleic Acids.

Which organic molecules are not macromolecules?

Lipids.

What is dehydration synthesis?

A process of removing water to bond molecules together, a form of anabolism.

What is hydrolysis?

A process of adding water to break down molecules, a form of catabolism.

What is the chemical formula for hydroxyl functional group?

-OH.

What is the chemical formula for carboxyl functional group?

-COOH.

What is the chemical formula for amino functional group?

-NH2.

What is the chemical formula for methyl functional group?

-CH3.

What is the chemical formula for phosphate functional group?

-PO4.

What is the chemical formula for carbonyl functional group?

-CO.

What are carbohydrates composed of?

Carbon, hydrogen, and oxygen in a 1:2:1 ratio.

What are monosaccharides?

The monomers of carbohydrates, examples include glucose, fructose, and galactose.

What is the chemical formula for monosaccharides?

C6H12O6.

What are dimers of carbohydrates?

Two monosaccharides linked together, examples include sucrose and lactose.

What are polysaccharides?

Polymers formed from many monosaccharides, examples include starch and cellulose.

What are lipids characterized by?

Hydrophobic properties and do not form polymers.

What are triglycerides?

A type of lipid used for energy storage.

What are the functions of proteins?

Enzymes, structural components, and hormones.

What is the monomer of proteins?

Amino acids.

What are nucleic acids responsible for?

Holding hereditary information and genetic inheritance.

What are the two types of nucleic acids?

DNA and RNA.

What are the nitrogen bases in DNA?

Adenine, Thymine, Guanine, and Cytosine.

What is the role of enzymes?

Biological catalysts that lower activation energy and speed up reactions.

What distinguishes exothermic reactions from endothermic reactions?

Exothermic reactions release energy, while endothermic reactions absorb energy.