Unit One Bio

Water

Composed of two hydrogen molecules covalently bonded to an oxygen molecule, forming a polar compound with distinct regions of charge.

Hydrogen Bonds

Weak bonds formed between a proton in one molecule and an electronegative atom of another molecule, such as between oxygen and hydrogen in water.

Cohesion and Adhesion

Cohesion is the tendency of molecules of the same kind to stick together, while adhesion is the attraction between dissimilar molecules, responsible for capillary action in water.

Carbon

An element crucial for life on Earth, known for its ability to form four bonds with other elements, making it the basis of organic molecules.

Macromolecules

Large biological molecules like carbohydrates, lipids, proteins, and nucleic acids, formed by the dehydration synthesis of monomers and essential for life processes.

Proteins

Organic molecules made of amino acids connected by peptide bonds, with diverse structures and functions crucial for organisms.

Amino Acids

Building blocks of proteins, consisting of a central carbon atom with an amino group, a carboxyl group, a hydrogen atom, and an R group that determines the amino acid's identity.

Protein Structure

Proteins have primary, secondary, tertiary, and quaternary structures, with amino acids linked by peptide bonds and folding patterns determining their functions.

Carbohydrates

Immediate energy sources and structural elements in organisms, consisting of monosaccharides, disaccharides, and polysaccharides with repeating (CH2O)n units.

Lipids

Nonpolar macromolecules like fats, waxes, and phospholipids, serving as energy storage and structural components in cell membranes.

DNA

Deoxyribonucleic acid, a polymer of nucleotides carrying genetic information, composed of a sugar, a phosphate group, and a nitrogenous base.

Dehydration synthesis and Hydrolysis

In dehydration synthesis, a covalent bond forms between two monomers, releasing water in the process. The reverse process breaks down polymers into monomers; this is called hydrolysis, meaning the bond is lysed by water. Synthesis reactions generally use energy, which is then stored within the covalent bonds of the macromolecule. When hydrolysis occurs, this energy is released for the cell to use.

Primary Structure

The composition and location of amino acids in the polypeptide chain confer their properties to the resulting protein and affect the shape of the protein. Amino acids can be charged, uncharged, hydrophobic, or cause changes in the 3D structure of the protein. The composition and order of amino acids

The secondary structure

When proteins fold due to interactions between elements in the amino acid backbone (not including R groups). These folds include A helixes, which are helical structures formed by hydrogen bonds between carbonyl groups of one amino acid and the amino group of another that is four amino acids down the line. This structure pushes R groups to the outside of the helix, giving them more opportunity to interact. B sheets are another secondary structure formed when sections of the polypeptide chain are parallel to each other. This structure also presents R groups outward on top and bottom, so they can interact.

Tertiary structure

Interactions between R groups of the same protein. These can include all different types of non-covalent bonds forming between groups or can include strong di-sulfide bonds. Tertiary structures minimize the free energy of a protein by taking the most energetically stable position.

Quaternary Structure

Quaternary structure forms between amino acids on different polypeptide chains. Protein structures can be denatured, meaning they lose their higher order structures due to changes in pH or temperature. However, they generally return to their proper structures when conditions return to normal. This means that most of the information needed to form a structure is retained within the polypeptide sequence of a protein

Saturated and Unsaturated fats

If all neighboring bonds in the hydrocarbon chain are single bonds, the fatty acid is called saturated. Saturated fats have straight fatty acid chains that can pack tightly together and form solids at room temperature. If there are double bonds in the chain, the fatt y acid is called unsaturated.

DNA Nucleotides

adenine (A), thymine (T), guanine (G), or cytosine (C). In RNA, uracil (U) is used instead of thymine. G and A molecules are called purines and consist of double nitrogenous rings. C, T, and U are called pyrimidines, and are composed of single nitrogenous rings. Two strands of DNA with complementary base pairs are linked with hydrogen bonds between base pairs to form the double helix pattern we are familiar with. Hydrogen bonds occur only between complementary pairs: C-G or A-T (or A-U, in the case of RNA). You’ll notice that purines bond with their complimentary pyrimidine. Cytosine guanine connections pair via three hydrogen bonds, while adenine-thymine pairs with double hydrogen bonds.