guanine(in) + Na(+)(in) => guanine(out) + Na(+)(out)
guanine(in) + na(+)(in) => guanine(out) + na(+)(out)
guanine(in) + Na(+)(in) => guanine(out) + Na(+)(out)
guanine(in) + na(+)(in) => guanine(out) + na(+)(out)