Complimentary base pairing

Complimentary base pairing - replaced by uracil. The mRNA...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Complimentary base pairing The adenine of one strand is always hydrogen-bonded to a thymine on the other. Similarly, Guanine is always paired with Cytosine. A-T G-C Antiparallel The end of a single strand that has the phosphate group is called the 5’ end. The other end is the 3’ end. The two strands of a DNA molecule run in opposite directions. Note the 5’ and 3’ ends of each strand in the diagram. RNA RNA (ribonucleic acid) is similar to DNA and is involved in the synthesis of polypeptides and proteins as discussed above. The table below lists differences between DNA and RNA. DNA RNA # Strands 2 1 (see diagram below) Sugar deoxyribose ribose Bases A, T, G, C A, U, G, C RNA is single-stranded as shown below. Codons One strand of DNA (the anti-sense strand) is used as a template to produce a single strand of mRNA. The bases in the mRNA strand are opposite (complimentary) to the bases in the DNA template strand; it resembles the sense strand of DNA except that the base thymine is
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: replaced by uracil. The mRNA contains three-letter (three-base) codes used to determine the sequence of amino acids in the polypeptide that it codes for. For example, in the diagram below, GUG is the code for valine. The sequence of codes in DNA therefore determines the sequence of amino acids in the protein. Each three-letter code in mRNA is a codon . It is the code for one amino acid. Click here for details on how information is stored in DNA. ATP ATP (adenosine triphosphate) is a nucleotide that is used in energetic reactions for temporary energy storage . Energy is stored in the phosphate bonds of ATP. When ATP breaks down to form ADP and P i , energy is released. Normally, cells use the energy stored in ATP by breaking one of the phosphate bonds, producing ADP. Energy is required to convert ADP + P i back to ATP. ATP is continually produced and consumed as illustrated below....
View Full Document

Page1 / 2

Complimentary base pairing - replaced by uracil. The mRNA...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online