Defendant was tried before a jury and found guilty of violating the Georgia Controlled Substances Act (sale of clonazepam). This appeal followed the denial of defendant’s motion for new trial. Held:

Defendant challenges the sufficiency of the evidence in the sole enumeration of error, arguing that the State’s key witness — a police informant — is not worthy of belief. This argument is without merit.

“ ‘On appeal of criminal convictions, we do not weigh the evidence or determine the credibility of witnesses; these are jury functions. When the jury has considered the evidence and made its finding, then on appeal the evidence is construed in favor of the jury’s verdict. Gurlaskie v. State, 196 Ga. App. 794 (397 SE2d 66). On review of a verdict of guilty, we merely determine whether the evidence is sufficient from which a rational trier of fact could conclude beyond a reasonable doubt that appellant committed the offense[s] as *182charged. Jackson v. Virginia, 443 U. S. 307 (99 SC 2781, 61 LE2d 560).’ Williams v. State, 202 Ga. App. 728 (1), 729 (415 SE2d 327).” Cornell v. State, 222 Ga. App. 476 (474 SE2d 634). In the case sub judice, Officer Michael Leonard of the Dalton Police Department gave a detailed account of a controlled drug buy he arranged at defendant’s residence. This testimony, the informant’s testimony regarding the manner in which defendant sold the informant a controlled substance during the controlled drug buy, and testimony confirming that this substance was actually a controlled substance under the Georgia Controlled Substances Act authorizes the jury’s finding that defendant is guilty, beyond a reasonable doubt, of the crime charged. Jackson v. Virginia, 443 U. S. 307, supra.

Judgment affirmed.