2.3 and 2.4 Flashcards
What is a nucleotide?
A biological molecule made from
- Pentose sugar
- A nitrogenous base
- A phosphate group
It contains the elements Carbon Hydrogen Oxygen Nitrogen And Phosphorus
They are monomers that make up DNA
What is the difference between RNA and DNA?
RNA has the bases A,U,C or G
and has a ribose sugar
DNA has the bases A,T,C or G
and has a deoxyribose sugar
What is a purine?
It contains two carbon-nitrogen rings joined together
They are Adenine and Guanine
What is a pyrimidine?
It contains only one Carbon-Nitrogen ring
Is smaller than a purine base
They are Cytosine and Thymine
What is the names of all the bases?
Adenine Guanine Cytosine Thymine Uracil
What is the structure of DNA?
Double helix shape
What do nucleotides help regulate?
Metabolic pathways
Where is DNA found?
Nucleus
Explain protein synthesis?
Transcription: A section of DNA unwinds (catalysed by DNA helicase) and acts as a template. The section is then copied to make mRNA (catalysed by RNA polymerase). The mRNA then leaves the nucleus and enter the cytoplasm where it is held by a ribosome. The instruction will be complimentary to the DNA strand with Thymine being replaced by Uracil.
Translation: In the cytoplasm, tRNA picks up amino acids. One end of tRNA carries one amino acid and the other end has a triplet code sequence that is complimentary to the codon on mRNA (known as anti codon). Once the mRNA is in the cytoplasm and attached to a ribosome, it is read by tRNA. tRNA molecules line up against mRNA.
What are DNA strands made up of?
Polynucleotides
Why do the bases have specific pairs?
A purine must always pair with a pyrimidine to give equal sized rings on the double helix
What is a phosphorylated nucleotide?
A nucleotide with added phosphate groups
What is the structure of ADP?
It contains the base adenine, the sugar ribose and two phosphate groups
What is the structure of ATP?
It contains the base adenine, the sugar ribose and three phosphate groups
What process is used to add phosphate groups to a molecule?
Phosphorylation