When man sinned, God cursed the earth the man, the woman and the serpent.
The man and woman are both mankind. I haven’t met anyone yet who thinks that Jesus only died for men and not women.
Galatians 3:13
Christ hath redeemed us from the curse of the law, being made a curse for us: for it is written, Cursed is every one that hangeth on a tree:
Deuteronomy 21:23
His body shall not remain all night upon the tree, but thou shalt in any wise bury him that day; (for he that is hanged is accursed of God

that thy land be not defiled, which the LORD thy God giveth thee for an inheritance.
So when Jesus is substituted as taking on the curse for men, and the curse being the direct penalty of sin, I see a very clear picture of penal substitution. That is, Jesus suffered the penalty of our sin.
The curse is death.
Hebrews 2:9
But we see Jesus, who was made a little lower than the angels for the suffering of death, crowned with glory and honour; that he by the grace of God should taste death for every man.
And since He tasted death for every man, and since death is the promise of the curse, Jesus took the penalty of the curse upon Himself.
It is as simple as that.