| Question | Answer |
| Proteins Contain ... | Carbon, Hydrogen, Oxygen, and Nitrogen and, Formed from Amino
Acids |
| Proteins | all proteins contain carbon, hydrogen, oxygen, and nitrogen and are the most abundant
organic molecules in the body |
| Amino acids are the... | monomer for proteins |
| Proteins carry out several functions including | Support
Movement
Transport
Buffering
Metabolic regulation
Coordination and control
Defense |
| Protein structure: | organic polymers that consist of long chains if similar organic molecules
called amino acids |
| There are 20 ... | amino acids in the body |
| Peptide bond | covalent bond between carboxyl group of one amino acid and the amino group of
another. |
| Peptides | molecules consisting of amino acids held together by peptide bonds |
| Dipeptide | molecule created containing 2 amino acids |
| Polypeptide | molecule created containing 3 or more amino acids |
| Polypeptides with more than 100 amino acids are usually called... | proteins; familiar
proteins include hemoglobin, collagen, and keratin. |
| Primary structure | sequence of amino acids along the length of single polypeptide. |
| Secondary structure: | shape that results from the presence of hydrogen bonds between atoms at
different parts of a polypeptide chain |
| Tertiary structure: | complex coiling and folding that gives a protein its final 3-D shape. |
| Quaternary structure: | nteraction between individual polypeptide chains to form a protein
complex. |
| Globular proteins | compact, generally rounded and soluble in water. |
| Globular proteins.. | can function only if they remain in solution
Unique shape of protein comes from tertiary structure
Hemoglobin and Myoglobin are both globular proteins |
| Fibrous proteins | form extended sheets or strands and insoluble in water |
| Fibrous proteins... | Tough, durable.
Usually play structural role in body.
Shape usually due to secondary structure |
| Shape of a protein determines its ... | functional characteristics and the sequence of amino
acids ultimately determine its shape. Ex. Certain cancers and Sickle Cell anemia result
from changing a single amino acid in the sequence of complex proteins |
| ertiary and Quaternary shapes of complex proteins depend not only on their amino acid
sequence, BUT also... | local environmental conditions |
| Substrates | Reactants in enzymatic reactions |
| Active site | Special region of enzyme that substrates must bind to |
| A Simplified View of Enzyme Structure and Function | Substrate binds to active site of enzyme.
Once bound to the active sites, the substrates are held together, making their interaction easier. Substrates binding alters the shape of the enzyme, and this change promotes product
formation. |
| A Simplified View of Enzyme Structure and Function.. | Product detaches from enzyme; entire process can now be repeated |
| Specificity | Each enzyme catalyzes only one type of reaction. |
| Saturated | Enzyme that has reached its saturated limit is said to be saturated |
| Saturation Limit | Substrate concentration required to reach the maximum rate of reaction |
| Cofactor | An ion or a molecule that must bind to an enzyme before substrates can also bind. |
| Without a cofactor, | the enzyme is intact but nonfunctional |
| With a cofactor, | the enzyme can catalyze a specific reaction |
| Coenzyme | non-protein organic molecules that function as cofactors.
Ex. Our bodies convert vitamins into co-enzymes. The human body cannot synthesize
most of the vitamins it needs, it must obtain these from your die |
| Temperature and PH... | affect enzyme function. |
| Denaturation | Change in tertiary and quaternary structure (unfolding of protein) that makes it
nonfunctional caused by high heat or low pH (acid) |
| Denaturation example | When you fry an egg, the temperature rises causing the protein in the egg white to
denature. Eventually causing the proteins to become completely and irreversibly
denatured forming an insoluble white mass |
| Glycoproteins and Proteoglycans are... | combination of protein and carbohydrate molecules |
| Glycoproteins | Large proteins with small carbohydrate groups attached |
| Proteoglycans | Large polysaccharide molecules linked by polypeptide chains |
