DNA, genes and chromosomes Flashcards
What is the name of the proteins that DNA is wrapped around?
Histones
What is the function of histones?
To help support DNA
Does prokaryotic DNA have histones?
No
What is a genome?
The complete set of genes in a cell or organism.
What is a proteome?
The full range of proteins that a cell is able to produce.
What kind of DNA do eukaryotic cells have?
Long and linear
What kind of DNA do prokaryotic cell have?
Short and circular
How does the DNA fit into a prokaryotic cell?
By supercoiling.
How does the DNA fit into a eukaryotic cell?
Coiling very tightly to make compact chromosomes.
What is a gene?
A sequence of DNA bases that code for the amino acid sequence of polypeptides and functional RNA.
What is the primary structure of a protein?
A sequence of amino acids.
What is functional RNA?
RNA molecules other than mRNA, which perform special tasks during protein synthesis. eg: tRNA, rRNA.
What are introns?
Sections of DNA that don’t code for amino acids.
What are exons?
Sections of DNA that do code for amino acids.
What is it called when DNA molecules combine with histone proteins?
A DNA-histone complex
What are homologous chromosomes?
A pair of nearly identical chromosomes, one maternal & one paternal.
Why are homologous chromosomes not identical?
Because they carry the same genes but not necessarily the same alleles of those genes.
What is an allele?
Different variations of a gene.
What is always the first triplet in the mRNA sequence?
AUG
What does AUG code for?
Methionine
What are stop sequences?
Triplets that don’t code for amino acids and mark the end of a polypeptide chain.
