DNA to Protein

Transcription & Translation

Genes and Proteins

What are these nucleotides telling us? Sequence of nucleotides in DNA contains

information to produce proteins Why does our body need these proteins?

Some proteins become key structures and regulators of cell functions

Others become important structures such as muscle filaments

Others, such as enzymes, control chemical functions that perform key life functions Example: breaking down glucose in cellular

respiration

What are the building blocks of proteins?

Amino Acids

RNA vs. DNA Is a nucleic acid Double stranded Sugar: deoxyribose Contains 4 nitrogen

bases

Is a nucleic acid Single stranded Sugar: Ribose Contains 4 nitrogen

bases: no thymine, instead uracil

What is the role of RNA?

THINK: How do automobile makers build a car?

“Workers” for protein synthesis Takes from DNA “HOW” the protein should be

assembled – then – amino acid by amino acid, they assemble the protein

BRAINPOP RNA

Types of RNA molecules

mRNA (messenger RNA) Brings instructions from DNA in the nucleus to

the ribosome (assembly line) rRNA (ribosomal RNA)

Makes up the ribosome Binds to mRNA and uses the instructions to

assemble the amino acids in the correct order tRNA (transfer RNA)

Delivers amino acids to the ribosome to be assembled into a protein

Transcription

Summary: DNA RNA DNA molecule is unzipped in the nucleus to

begin transcription Enzymes use a strand of DNA as a template to

produce RNA Recall: there is NO thymine (T) in RNA; instead,

thymine is replaced with Uracil (U) Therefore: A pairs with U AND C still pairs

with G mRNA carries this information from the

nucleus to the ribosome for protein production

Try transcribing the strand of DNA on your notes

RNA Processing

Nucleotide sequence transcribed from DNA to mRNA acts as the “genetic code” to build proteins

There are 20 common amino acids that make up all proteins in our body, from only 4 nitrogen bases

Translation

Summary: mRNA to protein Takes place in the cytoplasm at a

ribosome For proteins to be built, 20 different

amino acids floating in the cytoplasm must be brought to the ribosome by tRNA Each tRNA only attaches to 1 type of amino

acid Correct translation of mRNA depends upon

joining each mRNA codon with the correct tRNA anticodon. Codon: sequence of 3 mRNA bases Anticodon: sequence of 3 complimentary tRNA

bases

Translation

Try translating the mRNA code on the worksheet supplied to you