Veterinary Biochemistry & Metabolism

$K_m$ is the substrate concentration at which reaction rate is $\frac{V_{max}}{2}$ (B), hence its units are concentration (M, mM, $\mu$M) (A). It defines the hyperbolic relationship $V_0 = \frac{V_{max}[S]}{K_m + [S]}$ (C). Regulatory/allosteric enzymes show sigmoidal kinetics and do NOT follow standard Michaelis-Menten kinetics (D is false).

In pyrimidine nucleotides, the nitrogenous base is covalently linked to the C-1' carbon of the pentose sugar via a $\beta$-N-glycosidic bond through the N-1 atom of the pyrimidine ring (in purines, it involves N-9).

In oligonucleotide shorthand notation, adjacent nucleosides are linked by $3'-5'$ phosphodiester linkages, represented by the letter 'p' positioned between nucleotide symbols.