Molecules of Life Part II Flashcards

Practice vocabulary flashcards covering the biochemical foundations of life, specifically focusing on water properties, lipids, carbohydrates, nucleic acids, and protein structures based on the SB0014 lecture.

Specific Heat of Water

A property where water's high specific heat minimizes temperature fluctuations, providing a stable environment for organisms.

Cohesive Behavior

A property of water that facilitates water transport and surface tension for insects.

Expansion upon Freezing

A property where ice floats, insulating liquid water below for aquatic life.

Dehydration Reaction

A reaction where monomers join by removing water to form long chains called polymers.

Starch

A polysaccharide used by plants for energy storage.

Cellulose

A polysaccharide used by plants for rigid cell wall support.

Triglycerides

Lipids that serve as major energy reserves and provide structural insulation.

Phospholipids

Lipids that self-assemble into bilayers and are the main component of cell membranes.

Steroids

Lipids that act as chemical messengers and hormones, including cholesterol.

Nucleotide

The basic component of nucleic acid consisting of a pentose sugar, a phosphate group, and a nitrogenous base.

Deoxyribonucleic acid (DNA)

A biological molecule that stores genetic information and provides instructions for its own replication and for RNA synthesis.

Ribonucleic acid (RNA)

A biological molecule that helps translate genetic information into proteins.

Pyrimidines

A family of nitrogenous bases including cytosine, thymine, and uracil, characterized by a single six-membered ring.

Purines

A family of nitrogenous bases including adenine and guanine, characterized by a six-membered ring fused to a five-membered ring.

Nucleoside

A structure consisting of a nitrogenous base and a sugar (pentose).

Antiparallel

The arrangement in DNA where two strands run in opposite directions, one from $5' \rightarrow 3'$ and the other from $3' \rightarrow 5'$.

Complementary Base Pairing (DNA)

The specific pairing where Adenine (A) pairs with Thymine (T) through two hydrogen bonds, and Guanine (G) pairs with Cytosine (C) through three hydrogen bonds.

Amino Acids

The monomers of proteins, which mainly contain C, H, O, N and sometimes S and P.

Zwitterions

Dipolar ions that amino acids exist as, contributing to their amphoteric properties.

Amphoteric

The property of globular proteins to act as both an acid and a base, allowing them to function as buffers.

Peptide Bond

A bond formed through a condensation reaction linking the amino group of one amino acid with the carboxyl group of another.

Primary Structure

The specific and unique sequence of amino acids in a protein, determined by inherited genetic information.

Secondary Structure

Regions of a polypeptide chain that coil ($\text{α-helix}$) or fold ($\text{β-pleated sheet}$), stabilized by hydrogen bonds between the backbone groups.

Tertiary Structure

The overall 3D shape of a single polypeptide chain, stabilized by interactions between R groups such as hydrogen bonds, ionic bonds, hydrophobic interactions, and van der Waals interactions.

Disulfide Bridges

Strong covalent bonds that may form between the R groups of two cysteine residues to stabilize protein structure.

Quaternary Structure

The structure formed when two or more polypeptide chains (subunits) associate to form one functional protein.

Collagen

A fibrous protein with quaternary structure consisting of three polypeptide chains wound into a strong, rope-like triple helix.

Haemoglobin

A globular protein with quaternary structure consisting of four polypeptide subunits: two $\text{α-globin}$ chains and two $\text{β-globin}$ chains.