Biology calculator?

function translate(str)
    r = ""
    if str == "UUU" then
        r = "Phenylalanine"
    elseif str == "UUC" then
        r = "Phenylalanine"
    elseif str == "UUA" then
        r = "Leucine"
    elseif str == "UUG" then
        r = "Leucine"
    elseif str == "CUU" then
        r = "Leucine"
    elseif str == "CUC" then
        r = "Leucine"
    elseif str == "CUA" then
        r = "Leucine"
    elseif str == "CUG" then
        r = "Leucine"
    elseif str == "AUU" or str == "AUC" or str == "AUA" then
        r = "Isoleucine"
    elseif str == "AUG" then
        r = "Start or Methionine"
    elseif str == "GUU" or str == "GUC" or str == "GUA" or str == "GUG" then
        r = "Valine"
    elseif str == "UCU" or str == "UCC" or str == "UCA" or str == "UCG" then
        r = "Serine"
    elseif str == "CCU" or str == "CCC" or str == "CCA" or str == "CCG" then
        r = "Proline"
    elseif str == "ACU" or str == "ACC" or str == "ACA" or str == "ACG" then
        r = "Threonine"
    elseif str == "GCU" or str == "GCC" or str == "GCA" or str == "GCG" then
        r = "Alanine"
    elseif str == "UAU" or str == "UAC" then
        r = "Tyrosine"
    elseif str == "UAA" or str == "UAG" then
        r = "Stop"
    elseif str == "CAU" or str == "CAC" then
        r = "Histidine"
    elseif str == "CAA" or str == "CAG" then
        r = "Glutamine"
    elseif str == "AAU" or str == "AAC" then
        r = "Asparagine"
    elseif str == "AAA" or str == "AAG" then
        r = "Lysine"
    elseif str == "GAU" or str == "GAC" then
        r = "Aspartic Acid"
    elseif str == "GAA" or str == "GAG" then
        r = "Glutamic Acid"
    elseif str == "UGU" or str == "UGC" then
        r = "Cysteine"
    elseif str == "UGA" then
        r = "Stop"
    elseif str == "UGG" then
        r = "Tryptophan"
    elseif str == "CGU" or str == "CGC" or str == "CGA" or str == "CGG" then
        r = "Arginine"
    elseif str == "AGU" or str == "ACC" then
        r = "Serine"
    elseif str == "AGA" or str == "AGG" then
        r = "Arginine"
    elseif str == "GGU" or str == "GGC" or str == "GGA" or str == "GGG" then
        r = "Glycine"
    end
    return r
end

function intrans(word)
    if #word ~= 3 then
        return nil
    end
    local function trans(let)
        local kek = ""
        let = let:lower()
        if let == "a" then
            kek = "U"
        elseif let == "t" then
            kek = "A"
        elseif let == "c" then
            kek = "G"
        elseif let == "g" then
            kek = "C"
        end
        return kek
    end
    a = trans(string.sub(word,1,1))
    b = trans(string.sub(word,2,2))
    c = trans(string.sub(word,3,3))
    combine = a..b..c
    return combine
end

function begin(seq)
    local mrna = ""
    local protein = ""
    g = string.sub(seq,#seq,#seq)
    if g ~= " " then
        seq = seq.." "
    end
    for i=1,#seq do
        if string.sub(seq,i,i) == " " then
            local a = string.sub(seq,i-3,i-3)
            local b = string.sub(seq,i-2,i-2)
            local c = string.sub(seq,i-1,i-1)
            local abc = a..b..c
            local abcc = intrans(abc)
            local abca = translate(abcc)
            if i ~= 4 then
                protein = protein..", "..abca
                mrna = mrna.." "..abcc
            else
                protein = protein..abca
                mrna = mrna..abcc
            end
        end
    end
    return {mrna,protein}
end

function prin(tab)
    mrna = tab[1]
    protein = tab[2]
    print("mRNA : "..mrna.."\nProtein : "..protein)
end

prin(begin("TTT TTC TTA TTG CTC CTA CTG CTT ATT ATC ATA ATG GTT GTC GTA GTG TCT TCC TCA TCG CCT CCC CCA CCG ACT ACC ACA ACG ACT GCC GCA GCG TAT TAC TAA TAG CAT CAC CAA CAG AAT AAC AAA AAG GAT GAC GAA GAG TGT TGC TGA TGG CGT CGC CGA CGGAGT ACC AGA AGG GGT GGC GGA GGG"))