Carbonyl Carbon double-bonded to oxygen, C=O. Hydroxyl An oxygen bound to a hydrogen, OH. Alkane Only consisting of carbons and hydrogens. Alcohol An alkane with hydroxyl addition(s) and perhaps other additions as well.

ΔG = -n ℱ ΔE = – R T ln K’eq = – R T ln { [products] / [reactants] } ΔG ℱ Equivalent to 96.5 kJ V-1 mol-1 ΔE Difference between two half reactions. E = E° + (RT/nℱ) ln { [products, electron acceptors] / [reactants, electron donors] } R .0083 T 298 K [...]

Tend to stack, so small groups like glycine and alanine tend to be found in sheets. Large aromatic residues (Tyr, Phe and Trp) and β-branched amino acids (Thr, Val, Ile) are favored to be found in β strands in the middle of β sheets. Interestingly, different types of residues (such as Pro) are likely to [...]

The helix forms more readily than other conformations because it makes optimal use of hydrogen bonds. Alanine is most likely to form alpha helices, while proline and glycine are least likely to. Methionine, alanine, leucine, uncharged glutamate, and lysine (“MALEK” in the amino-acid 1-letter codes) all have especially high helix-forming propensities, whereas proline and glycine [...]

With strong acids and bases, they dissociate completely and you do not have to worry about a pKa value. With weak acids and bases, they do not dissociate completely — their disassociation (their relative strength) is according to their pKa value (for acids) or pKb value (for bases). A strong acid has a negative pKa [...]

[E] Concentration of free enzyme. [S] Concentration of free substrate. [ES] Concentration of enzyme-substrate complex. This is equal to [Et] [S] / (Km + [S] ). In the reaction E + S ⇔ ES ⇔ E + P, the rate of ES formation is V = k1 ( [ET - [ES] ) [S] — the [...]

First Order A ⇔ B Second Order A + B ⇔ C Pseudo First Order A + B ⇔ C (with [B] kept extremely high and [A] varied experimentally]

Term Overview Similarity The measure of bases or amino acids that are either identical or very similar (ie, leucine and isoleucine). Identity The measure of bases or amino acids that are identical.

Small chains of amino acids are known as peptides. These are biochemically very important; most hormones are peptides, and there are many peptide antibiotics. Proteins are long peptides, called polypeptides, and can sometimes consist of more than one polypeptide subunit interacting together. Some proteins have 104 amino acid residues (called residues because they are the [...]

The dielectric constant (ε, Greek epsilon) is a property of a solvent. It is a measure of how well the solvent reduces interactions between ions in solution. A dielectric constant greater than or equal to 20 means the medium is a good solvent (ie, at 20°C dH2O has an ε ≈ 80) and an ε [...]

Stereoisomers are molecules with the same chemical bonds but different configurations, which cannot be interconverted without temporarily breaking one or more covalent bonds. Configuration is the spatial arrangement of atoms, and occurs either around double bonds or at single-atom chiral centers; around either these, the substituents can be attached in different orders. The result is [...]

Oxygen is poorly soluble, making it impossible to transport more than a few millimeters in quantities sufficient enough to sustain life. Hemoglobin addresses this problem by binding oxygen so that it can be transported to tissues near and far. Hemoglobin exists in two forms: oxyhemoglobin does not carry oxygen, but its reduced heme iron can [...]

Water Is Stable Liquid water is essential for life because it provides stability and richness. It is temperature-stable, with a high heat capacity (it doesn’t get hot quickly when exposed to heat) that gives it a large heat of fusion (melts at a high temperature) and more importantly a large heat of vaporization (it takes [...]

Evolutionary trees (aka phylogenetic trees) began when Carolus Linnaeus began classifying more than 10,000 plants and animals over 200 years ago. Scientists are still classifying the 1.7 million identified species and organisms. A newly discovered insect by Tennessee scientists was named Cosberalla lamaralexanderi after the Tennessee senator Lamar Alexander. Systematics, the scientific study of the [...]

Separation / Purification The first step in the study of a protein is to separate it from other cellular components, or to isolate it in a pure form. But how does a researcher separate different cellular components and different proteins? Techniques include centrifugation, chromatography and SDS-PAGE. Once the different cell components are separated out, proteins [...]

Lipid Bilayer The lipid bilayer consists of phospholipids. Phospholipids consist of a nonpolar alkyl attached to a phosphate. The nonpolar alkyl resembles a tail. These nonpolar alkyls are hydrophobic, meaning they repel water. As a result, when phospholipids are mixed into water, the nonpolar alkyls will join together and the attached phosphates will have contact [...]

Molecules and their ability to cross the membrane Passive Transport Polar MoleculesLess than 3 carbonsNo net charge No energy required for transport. Cross fast with no channels or carriers. Passive or Active Biological monomers5-6 carbon sugars Sometimes energy is required to transport it across the membrane. Slow, too slow for metabolic processes, need channel or [...]

Amino acids have important roles in living organisms: they are the subunits (building blocks) of peptides and proteins. There are 23 naturally occuring amino acids present in all organisms. Their structure is shown below: the NH3+ is an amine (amino); the COOH forms COO- at ph7 (acid); and the R represents the functional group, which [...]

A protein’s biological specificity is determined by its structure and chemistry. Proteins can be separated into two broad classes based on whether they are present in all or specific cells: housekeeping proteins present in nearly every cell which maintain cell structure and function; and tissue-specific specialty proteins present in only some cells and with unique [...]

How are reduced energy currencies like NADH used to make ATP? It harnesses the exergonicity of electron transfers. The reaction ½ O2 + 2 H+ → H2O is very exergonic; the reactants have a very high reduction potential, a measure of electron affinity. Rather than allowing e- transfer to make HO in one hugely exergonic [...]