Water Properties, Biomolecules, and Protein Structures: A Biology Review

Hydrogen bond

The type of bond that holds two water molecules together.

Polar covalent bond

The type of bond that holds atoms together inside a single water molecule.

Hydrogen bonds in ice

They form a lattice that makes ice less dense than liquid water.

Floating ice importance

It insulates the liquid water below, allowing aquatic life to survive in winter.

High specific heat of water

It resists temperature change, helping regulate Earth's and organisms' temperatures.

Universal solvent

Water, because its polarity dissolves many substances.

Monomers of carbohydrates

Monosaccharides.

Glycosidic linkage

The bond that joins two monosaccharides.

Monomers of proteins

Amino acids.

Peptide bond

The bond that connects amino acids in a protein.

Monomers of nucleic acids

Nucleotides.

Phosphodiester bond

The bond that links nucleotides.

Types of nucleic acids

DNA and RNA.

Sugar in DNA

Deoxyribose.

Sugar in RNA

Ribose.

Nitrogen base in DNA

Thymine.

Nitrogen base in RNA

Uracil.

Purines

Adenine and Guanine (2 rings).

Pyrimidines

Cytosine, Thymine, Uracil (1 ring).

Function of DNA

Stores hereditary information.

Function of RNA

Transfers genetic code to make proteins.

Monomer of lipids

Glycerol + fatty acids (not a true polymer).

Ester bond

The bond that forms in fats between glycerol and fatty acids.

Saturated fats

Solid at room temperature due to no double bonds, resulting in straight chains that pack tightly.

Unsaturated fats

Liquid at room temperature due to double bonds, resulting in kinks that prevent tight packing.

Amphipathic phospholipids

They have hydrophilic heads and hydrophobic tails.

Phospholipid structure in water

Bilayer (basis of cell membranes).

Dehydration synthesis

Reaction that builds polymers by removing water.

Hydrolysis

Reaction that breaks polymers by adding water.

Primary structure of a protein

Sequence of amino acids (peptide bonds).

Secondary structure of a protein

Alpha helices or beta sheets (H-bonds).

Tertiary structure of a protein

3D folding from R-group interactions.

Quaternary structure of a protein

Multiple polypeptide chains joined together.

Factors that can denature a protein

pH, temperature, and salt concentration (not peptide bonds).

Cohesion

Water molecules stick to each other because of hydrogen bonding.

Adhesion

Water molecules stick to other surfaces