Whats the central dogma of biology A B

What’s the central dogma of biology? A. B. C. D. DNA RNA Protein DNA Protein Gene DNA Keratin Hair DNA RNA Amino Acid

What’s the 1 st step of protein synthesis? A. B. C. D. Protein Transcription Translation DNA

Where does transcription take place in the cell? A. B. C. D. Cytoplasm Ribosome Nucleus Cell Membrane

From Gene to Protein • Genes are DNA sequences that hold the instructions to build a protein. – For example, there’s a gene that codes for a protein called keratin. Keratin is the protein that makes our hair & nails.

Protein Synthesis DNA RNA Protein • Protein synthesis (making proteins from your genes) occurs in 2 steps: – Transcription – Translation

Where we left off… • We’ve completed the 1 st step of protein synthesis (transcription)… now what? TRANSLATION • We’ve created an m. RNA copy of the gene. • The m. RNA has left the nucleus & is headed to the cytoplasm.

Protein Synthesis Translation

Translation • The m. RNA made during transcription is used to make a protein. – DNA m. RNA Protein

Remember! • Proteins (sometimes called polypeptides) are macromolecules made of monomers called amino acids. So, to build a protein, we need to link together amino acids.

Translation – Step 1 • The m. RNA molecule (made during transcription) attaches to a ribosome in the cytoplasm.

Translation – Step 2 • The m. RNA is broken down into sets of 3 nucleotides, or codons. • The nucleotides are read in “words” made of 3 nucleotide “letters”. • Each “word” is called a codon & contains the genetic code for 1 amino acid.

Each codon on an m. RNA sequence codes for a specific amino acid.

Translation – Step 3 • As each codon of the m. RNA moves through the ribosome, the correct amino acid is brought to the ribosome by t. RNA.

• Each t. RNA molecule has a group of 3 nucleotides called the anticodon & an amino acid attached. – The anticodons pair with the codons.

In order for the t. RNA to attach the amino acid, it needs to bind to the m. RNA sequence using its anticodon. The anticodon is complementary to the codon!

The first “word”, or start codon, is always the same for every protein. It is always AUG.

Using the genetic code wheel, you can figure out which amino acid a codon represents. Which amino acid is associated with the start codon AUG? Methionine Move from the inside out!

There a total of 20 different amino acids that can be arranged in different ways to make different proteins.

Translation – Step 4 • The ribosome transfers the amino acid from the t. RNA to the polypeptide chain being formed in a process called elongation. – This forms a peptide bond between the amino acids, which is why proteins are called polypeptides.

Translation – Step 5 • The empty t. RNA molecule exits the ribosome & is recycled by the cell & can bind another amino acid.

Translation – Step 6 • The ribosome continues to match codons in the m. RNA with anticodons in t. RNA until it reads a codon that says “stop. ” When this happens, the ribosome releases the m. RNA & the protein.

Could you give me the amino acid sequence of this gene? 1. DNA 2. Make m. RNA 3. Separate m. RNA into codons 4. Use codon chart to find amino acids CACGTAGACTGAGGACTC GUGCAUCUGACUCCUGAG GUG-CAU-CUG-ACU-CCU-GAG Val-His-Leu-Thr-Pro-Glu