Ch 1 Learning Objectives: The Chemical Basis of Life

Flashcards based on lecture notes for Biochemistry review.

What is Biochemistry?

The scientific discipline that seeks to explain life at the molecular level.

What are the four main types of molecules studied in Biochemistry?

Carbohydrates, Nucleic Acids, Proteins, and Lipids.

What are the central questions in Biochemistry?

What are living organisms made of? How does an organism maintain its identity across generations? How do organisms acquire and use energy?

Besides answering the central questions in Biochemistry, what other themes does the field address?

Cells maintain a state of homeostasis, organisms evolve, and diseases can be explained at the biochemical level.

What are the elements primarily contained in biological molecules?

H, C, N, O, P, and S.

Name four common functional groups and linkages in biochemistry.

Amide, Imine, Phosphoric acid ester, Diphosphoric acid ester

What chemical groups does an amino acid contain?

An amino group, a carboxylic acid group, and a side chain.

What is the general chemical formula for carbohydrates?

(CH2O)n where n ≥ 3

What are the three major kinds of biological polymers?

Polypeptides and proteins, nucleic acids, and polysaccharides.

What type of bonds link amino acid residues in polypeptides and proteins?

Peptide bonds.

What type of bonds link nucleotide residues in nucleic acids?

Phosphodiester bonds

What type of bonds link glucose residues in polysaccharides?

Glycosidic bonds

Name the major functions of proteins, nucleic acids and polysaccharides

Proteins: metabolic reactions, Nucleic acids: encode information, Polysaccharides: store energy and support cellular structures

Define Enthalpy (H)

The heat content of a system

Define Entropy (S)

A measure of the system’s disorder or randomness

Define Gibbs Free Energy (G)

A measure of the free energy of a system based on H and S

What is the formula relating Gibbs free energy change to enthalpy change and entropy change?

ΔG = ΔH – TΔS

If ΔG < 0, is the reaction spontaneous or nonspontaneous?

Spontaneous or exergonic

If ΔG > 0, is the reaction spontaneous or nonspontaneous?

Nonspontaneous or endergonic

Define reduction in the context of chemical reactions.

Gain of electrons

Define oxidation in the context of chemical reactions.

Loss of electrons

According to the theory, where might life have originated?

High temperatures, H2S, and metal sulfides might have stimulated the formation of biological molecules.

Define prokaryotes

Small, unicellular organisms that lack a discrete nucleus and have no internal membrane system. Includes bacteria and archaea.

Define eukaryotes

Larger cells, contain a nucleus and other membrane-bound cellular compartments (organelles). May be unicellular or multicellular. Includes microscopic organisms as well as plants and animals.