3.4.1 DNA, genes and chromosomes Flashcards
What are the 3 components of nucleotides
Pentose sugar
Phosphate group
Organic base
Structure of DNA
Deoxyribose sugar
Phosphate group
Base (ATCG)
Double stranded
Helical
Role of DNA
Carries genetic information
Determines our inherited characteristics
Structure of RNA
Ribose sugar
Phosphate group
Base (AUCG)
Single stranded
Role of RNA
Transfers genetic information from DNA to ribosomes for protein synthesis
Which bases are purine and which are pyrimidine
Purine (double ring) A G
Pyrimidine (single ring) C T U
How is DNA in eukaryotic cells different from in prokaryotic cells
Euk - found in nucleus, long and linear. Associated with histones to form chromosomes.
MITO AND CHLORO CONTAIN PRO LIKE DNA
Pro - short and circular - no histones
What is the genetic code
The order of bases on DNA. Consists of codons
Features of the genetic code
Non-overlapping - each triplet is only read once
Degenerate - more than one triplet codes for the same amino acid
Universal - same bases and sequences used by all species
What is a gene
A sequence of bases on DNA molecule that codes for a specific sequence of amino acids to make a polypeptide
Can also code for functional RNA
What is a locus
The fixed position on a DNA molecule occupied by a gene
What is an allele
Different versions of the same gene
What are exons and introns
Exons - regions of DNA that code for amino acid sequences
Introns - dont code for anything
