Ribonucleic Acid

ProteinsProtein synthesis

Transcription translation

During transcription, RNA polymerase unwinds the DNA and adds in thecomplementary nucleotides to make a single stranded piece of mRNA. Ligase helps the DNA strand close and the mRNA moves out of the nucleus.

During translation, a ribosome attaches to the mRNA at the start codon (AUG).The codons on the mRNA match with the complementary anti-codons ontRNA molecules, which carry the amino acids. The amino acids at strung togetherforming a polypeptide.

Insulin is a hormone that carries a signal from cell-to-cell, telling the body to absorb glucose out of the blood.

To maintain the integrity of the DNA, and so that multiple proteins canbe made at once (from multiple mRNA molecules).

mRNA

riboseuracil

3

Unwinds the DNA double helix and adds in complementary RNA nucleotides.uracil

3 nucleotides in a row on a strand of mRNA that code for an amino acidOnly mRNA

The structure and function of a protein is determined by the order of theamino acids and their chemical properties.

The genetic code is the set of “rules” or code that allows us to transfera DNA sequence into a protein.

64 20amino acid

The same base pair rules and codon table can be used to transcribe and translate proteins for all living organisms.

out of the nucleus (cytoplasm)3

Ribosome (made of rRNA)

rRNA stands for ribosomal RNA. This RNA makes up the ribosome and is the place where mRNA is translated into a protein.

tRNA stands for transfer RNA. This RNA has an anti-codon on one end and the amino acid on the other. tRNA matches its anti-codon with the codon on the mRNA during translation, “dropping off” the correct amino acid at the ribosome.

A 3-nucleotide sequence on tRNA that is complementary to the codon.

The anti-codon “tells” the tRNA where to take its amino acid, just like anaddress “tells” the mailman where to take the envelope.

A stop codon (UAA, UAG, UGA)

2

3

4

5

6

Endomembrane system

Ribosomes made by the rough ER are either excreted out of thecell, imbedded into the cell membrane, or left inside a vesicle tobecome a lysosome.

nucleolus

Bound ribosomeNucleus/nuclear membrane

Rough ER

Smooth ERVesicle

Golgi complex

LysosomeCell membrane

A U G G G G C U A C G A U U A G U C C U G A G G

Met - Gly - Leu – Arg – Leu – Val – Leu – Arg

AAA, AAG

Enzyme

Active site

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