UMN BIOC 3021 EXAM 2 QUESTIONS AND ANSWERS 2024/2025 | VERIFIED
Proteins that can be classified according to the type and arrangement of secondary structure - (a)
Antiparallel α-helix proteins
(b) Parallel or mixed β-sheet proteins
(c) Antiparallel β-sheet proteins
(d) Metal- and disulfide-rich proteins
Protein Domains or Modules - amino acid sequences
that are used repeatedly in the same protein or that are
found in different proteins
How many proteins domains? - 40-100
Step 1 of Protein Folding - A newly synthesized polypeptide first forms segments
of secondary structure (α-helix and β-sheet)
step 2 of protein folding - These coalesce into a globular structure, primarily
through hydrophobic interactions
Step 3 of protein folding - The final stable tertiary structure is generated by small
adjustments to the folded structure
Step 4 of protein folding - In the cell, protein folding may require the assistance of
molecular chaperones
quaternary Structure - refers to the association of protein subunits to
form multi-subunit complexes
,Monolayers and Micelles - produced by amphipathic lipid molecules
interacting with water
Micelles - lipid aggregates which have the hydrophobic tails in the
center and polar head groups facing outward
Bilayers - produced spontaneously by certain lipids, particularly
phospholipids, instead of micelles
Bilayers - Normally wrap around themselves to form closed vesicles, which
can consist of multiple bilayers.
Liposomes - Vesicles with a single lipid bilayer
Liposomes - Can be used as drug or enzyme delivery systems in
therapeutic applications.
the phospholipid bilayer - fluid supporting matrix for
membrane proteins, and both lipids and proteins are capable of
lateral and transverse movement.
Peripheral membrane proteins - external to the lipid bilayer
Integral membrane proteins - extend into or through the lipid bilayer
Lipid-Anchored Membrane Proteins - Membrane proteins are covalently linked to lipid molecules.
Peptidoglycan - the strong, protective peptide/
, polysaccharide layer of bacterial cell walls
Gram-negative bacteria - have the peptidoglycan layer
between two lipid bilayers
Gram-positive bacteria - have a thicker peptidoglycan layer external to a
single lipid bilayer.
Glycoproteins - on the cell surface
Proteoglycans - in the extracellular matrix
Glycoproteins - Proteins with covalently-linked oligo- or
polysaccharide groups
O-Linked glycoproteins - carbohydrate groups linked to
polypeptide chains via the hydroxyl groups of serine,
threonine, or hydroxylysine
O-Linked glycoproteins - Often found in cell surface glycoproteins.
N-Linked glycoproteins - carbohydrate groups linked via the amide
nitrogen of an asparagine residue
N-Linked glycoproteins - Found in many different proteins, including
immunoglobulins, ribonuclease, ovalbumin, and peptide
hormones.
Proteins that can be classified according to the type and arrangement of secondary structure - (a)
Antiparallel α-helix proteins
(b) Parallel or mixed β-sheet proteins
(c) Antiparallel β-sheet proteins
(d) Metal- and disulfide-rich proteins
Protein Domains or Modules - amino acid sequences
that are used repeatedly in the same protein or that are
found in different proteins
How many proteins domains? - 40-100
Step 1 of Protein Folding - A newly synthesized polypeptide first forms segments
of secondary structure (α-helix and β-sheet)
step 2 of protein folding - These coalesce into a globular structure, primarily
through hydrophobic interactions
Step 3 of protein folding - The final stable tertiary structure is generated by small
adjustments to the folded structure
Step 4 of protein folding - In the cell, protein folding may require the assistance of
molecular chaperones
quaternary Structure - refers to the association of protein subunits to
form multi-subunit complexes
,Monolayers and Micelles - produced by amphipathic lipid molecules
interacting with water
Micelles - lipid aggregates which have the hydrophobic tails in the
center and polar head groups facing outward
Bilayers - produced spontaneously by certain lipids, particularly
phospholipids, instead of micelles
Bilayers - Normally wrap around themselves to form closed vesicles, which
can consist of multiple bilayers.
Liposomes - Vesicles with a single lipid bilayer
Liposomes - Can be used as drug or enzyme delivery systems in
therapeutic applications.
the phospholipid bilayer - fluid supporting matrix for
membrane proteins, and both lipids and proteins are capable of
lateral and transverse movement.
Peripheral membrane proteins - external to the lipid bilayer
Integral membrane proteins - extend into or through the lipid bilayer
Lipid-Anchored Membrane Proteins - Membrane proteins are covalently linked to lipid molecules.
Peptidoglycan - the strong, protective peptide/
, polysaccharide layer of bacterial cell walls
Gram-negative bacteria - have the peptidoglycan layer
between two lipid bilayers
Gram-positive bacteria - have a thicker peptidoglycan layer external to a
single lipid bilayer.
Glycoproteins - on the cell surface
Proteoglycans - in the extracellular matrix
Glycoproteins - Proteins with covalently-linked oligo- or
polysaccharide groups
O-Linked glycoproteins - carbohydrate groups linked to
polypeptide chains via the hydroxyl groups of serine,
threonine, or hydroxylysine
O-Linked glycoproteins - Often found in cell surface glycoproteins.
N-Linked glycoproteins - carbohydrate groups linked via the amide
nitrogen of an asparagine residue
N-Linked glycoproteins - Found in many different proteins, including
immunoglobulins, ribonuclease, ovalbumin, and peptide
hormones.
