Genes Flashcards
What is a nucleotide made up of?
A phosphate group, a carbon sugar molecules and 1 of 4 nitrogenous bases.
What is the structure of DNA?
2 complementary anti parallel chains of nucleotides
What is the difference between the 5’ and 3’ end?
The 5’ end is the end where the 5th carbon on the sugar molecule is at the end of the chain whereas the 3’ end is where the 3rd carbon on the end sugar molecule is at the end
Why is DNA described as universal?
All 4 nitrogen base pairs are found in the DNA of every living thing
What are the 4 base pairs in DNA?
Cytosine, thymine, adenine and guanine
How would you tell the difference between cytosine and adenine?
Adenine is a purine and hence has 2 rings where as cytosine is a pyrimidine and only has 1 ring
How would you tell the difference between adenine and guanine
Guanine has an oxygen in it whereas adenine doesn’t. Guanine also forms 3 H bonds instead of adenines 2
What bases are pyrimidines?
Cytosine, uracil and thymine
What bases are purines?
Adenine and guanine
What base does adenine pair with in DNA?
Thymine
What base does guanine pair with?
Cytosine
What are each bases complementary pairing in DNA?
G and C (3 H bonds)
A and T (2 H bonds)
What base does uracil pair with?
Adenine
How is RNA different to DNA?
It is only single stranded, contains a ribose sugar molecule and has uracil in place of thymine
What is tRNA?
Transfer RNA, which brings amino acids to the ribosomes
What is mRNA?
Messenger RNA, it is a copy of the template strand of DNA that codes for proteins
What is rRNA?
Ribosomal RNA, structural component of a ribosome
How are nucleotides joined together?
Through nucleotide polymerisation, a nucleotide triphosphate will bind to the 3’ end of a DNA chain and 2 of its phosphate molecules are posed in the process