nucleotides🧬 Flashcards
how does the structure of dna allow replication
- double stranded
- each strand acts as template
- h bonds easily broken between bases
- complementary base pairing
- purine only binds to pyramidine due to different sizes
- a to t, c to g
role of mRNA
carries genetic info out of nucleus to ribosome for protein synthesis
how many hydrogen bonds between a and t
how many hydrogen bonds between c and g
a and t= 2
c and g= 3
why are there 64 combinations of codons but only 20 amino acids
- several triplets code for one amino acid
- some used for start or stop
- mutation may be silent
why is dna replication semi conservative
- one new strand one old strand
- each strand acts as template to be copied
why is complementary base pairing important for dna replication
- formation of identical dna
- reduces occurence of mutations
- allows formation of hydrogen bonds
how is glucose well suited to its function
- easily broken down to release energy
- soluble so good for transport
- small molecule for transport/diffusion across cell membrane
describe structural relationship between deoxyribose and other components of dna molecule
- phosphodiester bond to adjacent phosphate
- forms backbone
- bond with base and phosphate
- part of nucleotide
how is dna analysis useful to taxonomists
- compare dna
- more similar dna=closer relationship
- used to put organisms into groups
evidence used to classify organisms
- biochemical
- fossil record
- anatomy
- embryology
why is dna evidence for a species from 1948 no longer useful
mutations have occures since then so different dna
why can we study model organisms such as mice to learn about human dna
- similar genes
- similar metabolism
- same kingdom
how does pairing of bases allow formation of identical DNA
- a to t ,c to g
- hydrogen bonding
- purine only to pyramidine due to different sizes
