CPC Biochemistry & Biological Chemistry Flashcards
6 cards from real CPC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CPC Biochemistry & Biological Chemistry flashcards as text
Which bond type is primarily responsible for the secondary structure (α-helix and β-sheet) of proteins?
Answer: Hydrogen bonds between backbone NH and C=O groups
Secondary structures are stabilized by hydrogen bonds between the peptide backbone's NH groups and carbonyl (C=O) groups at regular intervals along the chain, forming α-helices and β-sheets.
In enzyme kinetics, the Michaelis constant (Km) represents:
Answer: Substrate concentration at which reaction velocity is half of Vmax
Km is the substrate concentration [S] at which the reaction velocity equals Vmax/2; a low Km indicates high enzyme affinity for the substrate.
Which nucleotide base pairs with adenine (A) in DNA?
Answer: Thymine (T)
In DNA, adenine pairs with thymine via two hydrogen bonds (A=T), while guanine pairs with cytosine via three hydrogen bonds (G≡C), following Chargaff's base pairing rules.
The citric acid cycle (Krebs cycle) primarily occurs in which cellular compartment?
Answer: Mitochondrial matrix
The citric acid cycle takes place in the mitochondrial matrix, where acetyl-CoA (from pyruvate oxidation) is fully oxidized to CO2, generating NADH, FADH2, and GTP.
Which lipid class forms the basic structural component of biological cell membranes?
Answer: Phospholipids
Phospholipids form the lipid bilayer of cell membranes due to their amphipathic nature: hydrophilic phosphate head groups face aqueous environments while hydrophobic fatty acid tails face inward.
The Southern blot technique is used to detect:
Answer: Specific DNA sequences in a sample
Southern blotting separates DNA fragments by gel electrophoresis, transfers them to a membrane, and uses a labeled complementary probe to detect specific DNA sequences by hybridization.