Biological Chemistry Lecture 5: Proteins

Fibrous proteins are elongated and insoluble, providing structural support.

Globular proteins are generally soluble in water.

Transport or carrier proteins transport ions or molecules in the body.

<p>Nutrient or storage proteins.</p> Signup and view all the answers

<p>Simple proteins and conjugated proteins.</p> Signup and view all the answers

<p>Regulatory proteins regulate cellular or metabolic activities.</p> Signup and view all the answers

<p>Contractile and mobile proteins.</p> Signup and view all the answers

<p>Amphoteric amino acids can act as both acids and bases.</p> Signup and view all the answers

<p>Enzymes are classified as enzymatic proteins because they function as biological catalysts.</p> Signup and view all the answers

<p>A prosthetic group is a non-protein component that binds to the protein part (apoprotein).</p> Signup and view all the answers

<p>They are nonpolar and hydrophobic.</p> Signup and view all the answers

<p>Aromatic R groups are relatively nonpolar and hydrophobic, while polar uncharged R groups are hydrophilic.</p> Signup and view all the answers

<p>They contain a net positive charge.</p> Signup and view all the answers

<p>Selenocysteine functions as a site for redox reactions due to its unique selenium composition.</p> Signup and view all the answers

<p>They can donate protons as acids or accept protons as bases.</p> Signup and view all the answers

<p>A zwitterion can act as both a proton donor and a proton acceptor.</p> Signup and view all the answers

<p>Negatively charged R groups have a net negative charge, while polar uncharged groups do not.</p> Signup and view all the answers

<p>Citrulline is involved in the urea cycle; Desmosine is crucial for elastin structure.</p> Signup and view all the answers

<p>Derived proteins are proteins that have been modified or degraded from their original form. Examples include coagulated proteins and peptones.</p> Signup and view all the answers

<p>Albumins are water-soluble proteins that coagulate upon heating, while globulins are insoluble in pure water but soluble in dilute salt solutions.</p> Signup and view all the answers

<p>The α-carbon in amino acids is significant because it is a chiral center, which allows amino acids to exist as enantiomers. It is bonded to four different groups: a carboxyl group, an amino group, an R group, and a hydrogen atom.</p> Signup and view all the answers

<p>Examples include Ala for alanine, Gly for glycine, and Ser for serine.</p> Signup and view all the answers

<p>The five main classes are nonpolar aliphatic, aromatic, polar uncharged, positively charged, and negatively charged amino acids.</p> Signup and view all the answers

<p>The first amino acid to be discovered was asparagine, in the year 1806.</p> Signup and view all the answers

<p>Carbons in an amino acid are identified by designating the α carbon as the central carbon, and then additional carbons in the R group are designated as β, γ, δ, etc., or numbered from the highest priority substituent.</p> Signup and view all the answers

<p>All common amino acids except glycine are optically active because their α-carbon is attached to four different groups, allowing for two stereoisomers.</p> Signup and view all the answers