Quiz 1

Asparate

(asp). Acidic side group

Glutamate

(glu). Acidic side group

Arginine

(arg). Basic side group

Lysine

(lys). Basic side group

Cysteine

(cys). Sulfur containing.

Proline

(pro). Kink-inducing

Cysteine folding

Two adjacent cysteins form a disulfide bond. In the cytoplasm they remain reduced but they readily form in oxidizing environments.

Ionic bonding

The acidic and basic amino acids form these.

isoelectric point

the pH at which a protein is no longer donating or accepting protons, it is neutral.

Secondary protein structure

local folding driven by hydrogen bonds. alpha and beta helices

alpha helices

all side chains outward, vertical hydrogen bonding. Within one peptide chain.

beta helices

side chains alternate pointing up and down. These are across two peptide chains

Reading amino acid chains

Read N to C. Amine to carbon with R group to carbonyl.

Sickle cell anemia

At position 6, Glu becomes Val. Val is extremely hydrophobic and so hemoglobin tries to bury it but new Val become exposed and so stacking occurs and this causes the blood cells to sickle. This makes it harder for red blood cells to move through arteries and causes finger swelling.

Hydrophobic interactions

decrease mobility of water along hydrophobic surfaces causes a decrease in entropy which disrupts hydrogen bonding and hydrophobic residues cluster.

Amino acids

Composed of an amine, a carboxylic acid, and an R group. pH of \~ 7.4