BIOC 3021- EXAM 1 QUESTIONS AND ACCUARATE ANSWERS 2024/2025 |
VERIFIED
what type of protein structure is formed by H bonding of amino acid residues? - secondary
what are the 2 basic types of secondary protein structure? - alpha helix and beta sheet
Describe the alpha helix - a spiral structure formed by a single polypeptide chain;
each C=O is H bonded to the N-H group that is 4 amino acids down the strand
Describe the beta sheet - H bonds are between strands rather than within a strand
what are the 2 types of beta sheets? Which one is more stable? - Parallel (H bonds angled) and
antiparallel n(H bonds are colinear with the covalent bonds-this one is more stable)
what do we call a sharp bend in a polypeptide chain that allows the strand to reverse its direction (fold
up on itself)? - beta turn
what protein shape contains segments of both alpha helices and beta sheets? - globular proteins
what protein structure is linear and serves as a structural role in cells? Hint: these structures tend to
have specialized tertiary structure - fibrous proteins
what is the tertiary structure of collagen? (main component of connective tissue) - Collagen is a
fibrous protein that consists of a special helix of 3 intertwined polypeptide chains (triple helix that is
right handed and held together by H bonds)
what is the tertiary structure of alpha keratin? (found in hair, fingernails) - coiling of alpha helices
what is the tertiary structure of fibroin and beta keratin? - primarily stacked beta sheets
, In addition to the polypeptide chain, what type of protein contains a component such as carbohydrate,
lipid, nucleic acid, phosphate groups, metal ions, heme, or flavin? - conjugated proteins
In what state do water molecules form a rapidly changing, random network of H bonds? - liquid
state
how do water molecules interact with ions? - they form hydration shells around ions (direct ionic
interaction)
how do water molecules interact with hydrophobic/nonpolar solutes? - they form clathrate
(cagelike/hexagonal) structures around the hydrophobe (transient, no direct interaction)
how do water molecules interact with polar solutes? - they form H bonds with the polar solute
how do water molecules interact with amphiphilic molecules? - they form micelles
What does pH measure? - hydrogen ion concentration
what system buffers the intracellular fluid of cells? - phosphate buffer system
what 2 ions are involved in the phosphate buffer system? - H2PO4(-) and HPO4(2-)
what is the important buffer system of blood plasma? - carbonate buffer system
what 2 molecules make up the carbonate buffer system? - HCO3(-) and H2CO3 (carbonic acid)
pyrimidine structure - single ring structure
purine structure - double ring structure
VERIFIED
what type of protein structure is formed by H bonding of amino acid residues? - secondary
what are the 2 basic types of secondary protein structure? - alpha helix and beta sheet
Describe the alpha helix - a spiral structure formed by a single polypeptide chain;
each C=O is H bonded to the N-H group that is 4 amino acids down the strand
Describe the beta sheet - H bonds are between strands rather than within a strand
what are the 2 types of beta sheets? Which one is more stable? - Parallel (H bonds angled) and
antiparallel n(H bonds are colinear with the covalent bonds-this one is more stable)
what do we call a sharp bend in a polypeptide chain that allows the strand to reverse its direction (fold
up on itself)? - beta turn
what protein shape contains segments of both alpha helices and beta sheets? - globular proteins
what protein structure is linear and serves as a structural role in cells? Hint: these structures tend to
have specialized tertiary structure - fibrous proteins
what is the tertiary structure of collagen? (main component of connective tissue) - Collagen is a
fibrous protein that consists of a special helix of 3 intertwined polypeptide chains (triple helix that is
right handed and held together by H bonds)
what is the tertiary structure of alpha keratin? (found in hair, fingernails) - coiling of alpha helices
what is the tertiary structure of fibroin and beta keratin? - primarily stacked beta sheets
, In addition to the polypeptide chain, what type of protein contains a component such as carbohydrate,
lipid, nucleic acid, phosphate groups, metal ions, heme, or flavin? - conjugated proteins
In what state do water molecules form a rapidly changing, random network of H bonds? - liquid
state
how do water molecules interact with ions? - they form hydration shells around ions (direct ionic
interaction)
how do water molecules interact with hydrophobic/nonpolar solutes? - they form clathrate
(cagelike/hexagonal) structures around the hydrophobe (transient, no direct interaction)
how do water molecules interact with polar solutes? - they form H bonds with the polar solute
how do water molecules interact with amphiphilic molecules? - they form micelles
What does pH measure? - hydrogen ion concentration
what system buffers the intracellular fluid of cells? - phosphate buffer system
what 2 ions are involved in the phosphate buffer system? - H2PO4(-) and HPO4(2-)
what is the important buffer system of blood plasma? - carbonate buffer system
what 2 molecules make up the carbonate buffer system? - HCO3(-) and H2CO3 (carbonic acid)
pyrimidine structure - single ring structure
purine structure - double ring structure
