RNA Transcription DNA stands for deoxyribonucleic acid A

RNA Transcription

DNA stands for deoxyribonucleic acid. A nucleic acid is a long repeating chain of nucleotides.

The nitrogen bases are on the inside of the DNA double helix. The information in DNA is “written” with nitrogen bases.

The sequence of nitrogen bases provides the instructions for making ribosomes and proteins. Each region of DNA that is used to make a protein is called a gene.

Transcription The primary purpose of transcription is to make copies of the information found in the DNA. The information in a gene is copied from DNA into a similar molecule called RNA.

Transcription Before DNA can be copied, it must unwind and the two strands must separate between the nitrogen bases.

Transcription Once the strands of DNA are separated, enzymes can use the information in the DNA to make RNA copies of the gene. Enzyme = RNA Polymerase

Transcription The RNA molecules are sent out into the cytoplasm where they attach to ribosomes. Ribosomes are the cell’s workforce which use the instructions to build the cell’s proteins.

Transcription happens in ALL cells. However, in eukaryotic cells, transcription occurs in the nucleus where the DNA is located. Nucleus

Transcription The RNA then travels out of the nucleus to find ribosomes. Many proteins are made by the ribosomes in the cell’s “protein factory”, the rough endoplasmic reticulum. Free Ribosome Nucleus Ribosomes in Endoplasmic Reticulum

Gene Expression Gene expression describes the process of using the information in the genes of DNA to make products in the cell. Transcription is the first step of gene expression.

Gene Expression It is important that you understand that gene expression is a regulated process. This means that the cell controls how the DNA is used to make proteins and other products.

Gene Expression The cell turns genes ON and OFF so that only certain genes in the cell are expressed. This means that only specific genes are being transcribed. ON

Gene Expression The cell turns genes ON and OFF so that only certain genes in the cell are expressed. This means that only specific genes are being transcribed. OFF No Products!

DNA vs. RNA DNA and RNA are very similar nucleic acids, but there are some important differences you need to know. DNA RNA

DNA vs. RNA DNA contains the sugar deoxyribose. RNA contains the sugar ribose. DNA deoxyribose RNA ribose

DNA vs. RNA DNA is double stranded. RNA is single stranded. DNA RNA

DNA vs. RNA DNA contains the nitrogen base thymine. RNA contains the nitrogen base uracil. DNA thymine RNA uracil

The 4 nitrogen bases in RNA: A Adenine U G C Uracil Guanine Cytosine

Base Pairing T A C G U A C G Important Fact: U and T will NEVER appear in the same strand together!

A C T C A G

Why can you immediately cross out answer choices B and D? These answer choices have. T and U in the same strand. Remember: U and T will NEVER appear in the same strand together!

Correctly label the sequence of the nitrogen bases in the RNA segment that is being transcribed from the DNA below. C G U A A G C U U C G A G U A U G C