Structure of Water and Hydrogen Bonding

Oxygen has a higher electronegativity, pulling electrons closer and creating a partial negative charge on oxygen and a partial positive charge on hydrogen.

A weak attraction between polar molecules that occurs when a slightly positive hydrogen atom from one molecule is attracted to a slightly negative atom (often oxygen or nitrogen) from another molecule.

A chemical bond that involves the transfer of electrons from a metal to a nonmetal, resulting in the formation of ions and a strong electrostatic attraction.

A chemical bond that involves the sharing of electrons between two atoms.

Compounds with many C-H bonds or evenly distributed electrons are hydrophobic (water-repelling). Ionic compounds and polar molecules are hydrophilic (water-loving).

Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur.

Plants get C and O from the air, H and O from water, and the rest from the soil. Animals and fungi get O from air, H and O from water, and all others from food.

Carbs: CHO, Lipids: CHO (phospholipids have P), Proteins: CHON and some S, Nucleic acids: CHONP

A reaction that forms a bond between two monomers (or adds a monomer to a polymer) by releasing a water molecule. For example, two amino acids can be joined together to form a dipeptide.

A reaction that breaks a bond between two monomers (or sections of a polymer) by adding a water molecule. This is the reverse of Dehydration Synthesis.

The basic building blocks of nucleic acids, such as DNA and RNA. They consist of a phosphate group, a 5-carbon sugar (deoxyribose or ribose), and a nitrogenous base.

The basic building blocks of proteins. They consist of an amino group, a carboxyl group, a central carbon, and a side chain (R-group).

The monomers of carbohydrates. They have C, H, and O in a 1:2:1 ratio (or close to it) and contain a carbonyl group (C=O).

The monomers of lipids. They are long chains of hydrocarbons with a carboxyl group at the end.

The two strands of DNA run in opposite directions, with one strand running 5' to 3' and the other running 3' to 5'.

In DNA, adenine (A) always pairs with thymine (T) via two hydrogen bonds, and guanine (G) always pairs with cytosine (C) via three hydrogen bonds.

The covalent bond between amino acids in proteins, formed between the nitrogen atom of one amino acid and the carbon atom of the next.

The linear sequence of amino acids in a protein chain. It's like the alphabet of the protein, determining the building blocks.

The local folding patterns of a protein chain, formed by hydrogen bonding between amino acids. This creates structures like alpha helices and beta sheets.

The overall 3D shape of a protein, determined by interactions between side chains (R groups) of amino acids. Folding is influenced by hydrophobic/hydrophilic interactions and disulfide bonds.

The arrangement of multiple polypeptide chains within a protein complex, held together by various bonds. Not all proteins have quaternary structure.

The sugar-phosphate backbone forms the outside of the DNA double helix, with the nitrogenous bases facing inwards for pairing. Imagine a ladder, with the backbone as the sides and the bases as the rungs.

DNA is typically double-stranded, while RNA is typically single-stranded. DNA uses deoxyribose sugar, while RNA uses ribose sugar.

Hydrogen bonds in DNA and proteins are disrupted by heat, causing the molecules to lose their structure (denaturation). Changes in pH also affect hydrogen bond stability.