ch. 19 amino acids and protein Flashcards
(22 cards)
Immunoglobulin, a protein that stimulates immune responses, would be classified as a __________ protein.
protection
The structural formulas of amino acids are the same EXCEPT for the
R group
The peptide bonds that combine amino acids in a protein are
amide bonds
Which level of protein structure occurs due to the particular sequence of amino acids, which are held together by peptide bonds?
primary structure
The interactions that are important in the secondary structure of a protein are
hydrogen bonds
In insulin, two peptide chains are held together in a single unit by
disulfide bridges
sequence of amino acids
primary structure
describes the alpha- helices and beta- sheets that are formed by hydrogen bonding between backbone atoms near each other in polypeptide chain
secondary structure
protein folding into 3-D shape stabilized by interactions between side chain R groups of amino acids
tertiary structure
result of 2 or more protein subunits assembling to form a larger biologically active protein complex
quaternary structure
what structural level of a protein is affected by denaturation
secondary, tertiary, quaternary
what level of protein structure is affected by hydrolysis
primary
A polypeptide of 50 or more amino acids is called a _____
protein
a globular protein that transports oxygen in blood consists of 4 polypeptide chains
hemoglobin
hemoglobin carries ______oxygen molecules
4
myoglobin carries ____ oxygen molecules
1
proteins are denatured above what temp
50 degrees Celsius
heavy metal ions such as ______ denature proteins by forming bonds with ionic residues or reacting sulfide bonds
Ag+, Pb2+, Hg2+
T/F: Proteins must be denatured before being digested
true
ionic attractions between ionized R groups of polar basic and polar acidic amino acids
salt bridges
hydrogen bonds form between the CARBONYL oxygen atoms and HYDROGEN atoms in the amide groups bending the polypeptide chian into a sheet
Beta- pleated sheet
HYDROGEN bonds form betwwen the oxygen of the carbonyl groups and hydrogen of the N-H groups of the amide bonds in the next turn of the a-helix
a- helix
