Ch6- Part A

How can DNA hold the plans for protein synthesis which occurs on the ribosome in the cytoplasm when the DNA never leaves the nucleus?

Because the code on the DNA is transcribed to the mRNA which carries the instructions for protein synthesis from the nucleus to the ribosome in the cytoplasm.

What are proteins?

Building materials for all living things. They build and repair body structures in us. Proteins determine characteristics of all living things.

What is the blueprint of protein synthesis?

DNA

Describe the structure of DNA.

DNA's shape is similar to a twisted ladder or a spiral staircase. The sides of the ladder are composed of alternating molecules of sugar and phosphate molecules. The rungs of the ladder are composed of complimentary nitrogen bases.

What is transcription? Where does it take place? How many sides of DNA participate?

Describes the copying of DNA to produce mRNA. It occurs in the nucleus. Only one side is copied or transcribed in mRNA.

What is replication? Where does it take place? How many sides of DNA participate?

Duplication or copying of DNA. It occurs in the nucleus. Two sides participate.

What does UGA codon signal?

For protein synthesis to stop.

What is a long chain of amino acids called? What types of bond holds the amino acids together?

Polypeptide and peptide bond.

Describe the two categories of nucleotides

Purines are composed of guanine and adenine. They are the larger of the two categories. Pyrimindines are composed of thymine, cytosine, and uracil. They are smaller than purines

How do today's scientists describe DNA's structure?

double helix

What is the scientific term used to describe DNA's shape?

double helix

Describe RNA

only one side, sugar=ribose, nitrogen base is uracil

How did Rosalind Franklin describe DNA's shape?

spiral

What four nitrogen bases are found in DNA?

thymine, adenine, cytosine, guanine

How did Watson and Crick describe DNA's structure?

twisted ladder

Describe DNA

twisted ladder, double helix. subunits call nucleotides, sides of the DNA ladder are composed of alternating phosphate and sugar molecules. Sugar=deoxyribose, the rungs of the ladder are the nitrogen bases nitrogen base is thymine