The anticodon of any codon will be the RNA nucleotides that complement the codon sequence. In RNA, adenine (A) complements uracil (U) while cytosine (C) complements guanine (G). Hence, for the codon 5' AUG 3', the complements will be 3' UAC 5'. Note that many of the incorrect answers contain thymine (T), a nucleotide not found in RNA.

The start codon for any strand of RNA begins with the codon that codes for the amino acid methionine. This is the first amino acid in a polypeptide chain. The abbreviation for methionine is: Met.

When translated from a ribosome on the rough endoplasmic reticulum (RER), the protein is moved through the RER until it is released in a lipid vesicle that can transport the protein to the plasma membrane, where the lipid vesicle fuses with the lipid membrane and the protein is secreted outside the cell. Smooth endoplasmic reticulum does not have ribosomes on it and is used for the production and transport of lipids and in detoxification. No ribosomes are found in the nucleus or directly on the plasma membrane. Ribosomes in the cytosol translate proteins that stay inside the cell.

In messenger RNA, each codon is three nucleotides that codes for a particular amino acid during translation. Purines and pyrimidines are types of nucleotides on DNA and RNA. The genetic code is redundant, but each codon only codes for one amino acid.

Chaperonin is the enzyme responsible for folding nascent polypeptide chains into the correct and functional 3-dimensional structure. Lipase is an enzyme that breaks down lipids, or fats. Amylase breaks down starches and complex carbohydrates or sugars. Helicase helps unwind the DNA helix during replication, and topoisomerase II helps keep the DNA untangled and acts as adhesive during DNA repair or replication.

Primary structure revolves around the sequence of amino acids, while secondary structure is achieved through hydrogen bonds interacting along the backbone of the polypeptide. Tertiary structure is achieved through interactions between the various side chains of amino acids and is required for the protein to be functional. Quaternary structure involves the interaction of two or more polypeptide subunits, and adds efficiency to their ability to catalyze a reaction.

Proteins have four levels of structure: primary, secondary, tertiary, and quaternary. These refer to the types of binding and folding that occur in the molecule that cause it to take on a stable shape. Hydrogen bonds occur between parts of the molecule containing slightly positive hydrogen, and other parts that may be slightly negative (generally containing oxygen). These bonds stabilize the protein's secondary structure, allowing more complicated folding into tertiary and quaternary structures. Alpha-helices and beta-pleated sheets form the common secondary protein structures.

Primary structure is driven by peptide bonding, while tertiary structure is derived from disulfide bonds and hydrophobic interactions. Quaternary structure describes the congregation of multiple subunits driven by hydrophobic interaction and protein-mediated assembly.

The formation of -helices and -pleated sheets constitute the secondary structure of a protein. These conformations are reinforced by hydrogen bonds between the atoms in the polypeptide chain.

Primary structure is determined by peptide bonds, which link adjoining amino acids in sequence. Tertiary structure is determined by disulfide bonds between cysteine residues and hydrophobic interactions. Quaternary structure is determined by interactions between multiple subunits of a protein.

Hydrogen bonding is responsible for giving shape to the secondary structures of proteins. The amino acids in the protein all carry carboxyl and amino termini, which are capable of forming hydrogen bonds. Secondary protein structure refers to the formation of alpha-helices and beta-pleated sheets through hydrogen bonding in the amino acid backbone. The R-groups are not involved in secondary structure.

Covalent bonds are used to permanently join atoms together, and are not seen in protein folding. Peptide bonds are a special class of covalent bonds that are responsible for holding the individual amino acids together, forming the protein's primary structure. Ionic bonds are generally formed between metals and non-metals, and are not generally seen in proteins.

Quaternary protein structure is distinguished by the fact that several polypeptide chains come together to make a functional protein. This is different than the first three levels of protein structure, which only involve one polypeptide chain. Quaternary structure is held together primarily by hydrophobic interactions between the polypeptide chains (ionic and/or hydrogen bonding is often seen as well). Each polypeptide chain forms a subunit of the protein.