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AminoAcids&Proteins
Biochemistry questions
| Question | Answer |
|---|---|
| Which group on the Amino Acid determines its polarity? | R- group |
| In which configuration are all amino acids in proteins? | L- configuration |
| Any compound that is both an acid AND a base is called what? | amphoteric |
| What are the two enantiomers or stereoisomers that all amino acids have? | Dextro (D - right) and Levo (L - left) |
| What is the function of the amino acids trypsin and chymotrypsin? | To break down proteins. |
| What is the tissue source that excretes amylase? | The pancreas AND salivary glands. |
| What type of bond is the covalent bond between a primary amino acid groups of one amino acid and the carboxylic group of a second amino acid? | Peptide bond. |
| What is the Henderson-Hasselbach equation used for? | To predict the net charge and isoelectric point of a protein. |
| Proteins have a minimum of _____ to ______ amino acids. | 30 to 50 |
| What is the most important of all biological compounds to the body? | proteins |
| Proteins are constructed from the same set of ____ amino acids. | 20 |
| Basic AA- contain amino groups and are fully pronated giving them a ______ charge. | positive |
| Carboxylic acids (-COOH) CANNOT exist in the presence of what? | a weak base |
| Compounds that have a positive charge on one atom and a negative charge on another atom are known as_______ | Zwitterions |
| What are the four levels of structure for proteins, and what is each comprised of? | Primary- sequence of amino acids Secondary- sequences linked by hydrogen bonds (alpha helix, Beta- pleated sheet) Tertiary- folds of twisted chains made by secondary structure Quaternary- arrangement of polypeptide chains if unit has 2 or more subunits |
| The pH where an amino acid has an equal number of positively and negatively charged atoms is called the ________. | Isoelectric point |
| How are proteins characterized? | Size, Charge, Binding properties, and Solubility. |
| Which type of amino acid has hydrophobic rings and are found in the core of proteins? | Aromatic Amino Acids |
| What equation is used to predict net charge and the isoelectric point of a protein? | Henderson- Hasselbalch equation |
| Average nitrogen content in proteins is ___ % by weight | 16% |
| What does adding a source of hydroxyl (OH-) do to the pH of a water solution of amino acids? | Raises the pH |
| The amino acid residue with the free -COOH group is called the ____? | C-terminal |
| What is one reason why the structure of proteins is important? | The structure is linked to diseases |
| What increases solubility by adding low amounts of salt (ammonium sulfate)? | "salting in" |
| What decreases solubility by adding large amounts of salt? | "salting out"" |
| At _____ pH's, amino acids have a negative charge. | high |