How does DNA affect traits?

DNA has a twisted-ladder shape that is caused by molecules called nucleotides

A nucleotide is a molecule made of a nitrogen base, a sugar, and a phosphate group.

The nitrogen bases bond and form the rungs of the ladder. There are four nitrogen bases: adenine (A), cytosine (C), thymine (T), and guanine (G).

 A and T always bond together. C and G always bond together.

Replication is the process of copying a DNA molecule to make another DNA molecule

The strands separate in many places. The nitrogen bases are exposed.

New nucleotides move into place and form new nitrogen base pair

This produces two identical strands of DNA

Proteins are important for every cellular process

Most genes contain instructions for making proteins

Proteins are made with the help of ribonucleic acid.

Ribonucleic acid (RNA) is a type of nucleic acid that carries the code for making proteins from the nucleus to the cytoplasm.

RNA also carries amino acids around inside a cell.

RNA forms a part of ribosomes.

Messenger RNA (mRNA)

Transfer RNA (tRNA)

Ribosomal RNA (rRNA)

They work together to make proteins.

 Transcription is the process of making mRNA from DNA.

mRNA nucleotides pair up with DNA nucleotides.

Completed mRNA can move into the cytoplasm.

Proteins are made of amino acids. The order of the nitrogen bases in mRNA determines the order of the amino acids in a protein

Three nitrogen bases on mRNA form the code for one amino acid. Each series of three nitrogen bases on mRNA is called a codon

There are 64 codons, but only 20 amino acids

Start codon: the codons which codes for an amino acid that is the beginning of a protein

Stop codon:  codes for the end of a protein and signal that translation should stop