Lecture 8 Flashcards
What is a genome?
sum total of genetic material of an organism
How does most of the genome exist?
most of the genome exists in the form of chromosomes
Do genome viruses contain dna or rna?
either one
What is a chromosome?
discrete cellular structure composed of a neatly packaged DNA molecule
4 facts about eukaryotic chromosomes?
DNA wound around histones
located in the nucleus
diploid (in pairs) or haploid (single)
linear appearance
2 facts about prokaryotic chromosomes
DNA condensed into a packet by means of histone-like proteins
single, circular chromosome
What is classical genetics of a gene?
the fundamental unit of heredity responsible for a given trait in an organism
What is molecular and biochemistry of a gene?
site on the chromosome that provides information for a certain cell function
What is a gene?
- a certain segment of DNA that contains the necessary code to make a protein or RNA molecule
- segment of DNA that contains code to make a group of related proteins or RNAs
What is the central theme of biology?
Central theme of biology: information flows from DNA to RNA to protein
what is transcription?
master code of DNA used to synthesize an RNA molecule
What is translation?
transcribed RNA used to produce protein
What do rna viruses do?
RNA viruses convert RNA to other RNA
What do retroviruses do?
retroviruses convert RNA to DNA
What are a wide variety of rna used to do?
A wide variety of RNAs are used to regulate gene function
What is a codon?
groups of three nucleotides that dictate which amino acid is added to the growing peptide chain
what are the 3 differences between eurkaryotic and prokaryotic transcription and translation?
Start codon is AUG for both, but in eukaryotes, it codes for a different form of methionine
Eukaryotic mRNAs code for just one protein, unlike bacterial mRNAs, which often contain information from several genes in series
Eukaryotic transcription takes place in the nucleus and must pass through pores in the nuclear membrane to the cytoplasm for translation
Eukaryotic genes do not exist as an uninterrupted series of triplets coding for a protein