ST.1 Structure and the Organisation of DNA H (DNAG) Flashcards
What does DNA encode?
DNA encodes hereditary information in a chemical language
Where do cells store their genetic information?
All cells stores their genetic information in the base sequence of DNA
What is the structure of a DNA nucleotide composed of?
The structure of a DNA nucleotide is composed of deoxyribose sugar, a phosphate and a base
What do nucleotides form when they bond?
Nucleotides bond to form a sugar phosphate backbone
What do base pairs do in DNA?
Base pairs (A,T,G,C) hold the 2 strands together by hydrogen bonds, forming a double helix
What base pairs always pair together?
Adenine and thymine, guanine and cytosine
Explain the structure of DNA
DNA is a double-stranded, antiparallel (one strand goes from 3’ to 5’ the other from 5’ to 3’) structure with a deoxyribose and phosphate backbone held together by internal base pairs
What shapes can DNA molecules be?
The DNA molecule can be circular or linear
Where are circular chromosomal DNA and plasmids found?
Circular chromosomal DNA and plasmids are found in prokaryotes
Where are circular plasmids found?
Circular plasmids are found in yeast
Where are circular chromosomes found?
Circular chromosomes are found in the mitochondria and chloroplasts of eukaryotes
What is DNA like when it’s found in linear chromosomes of the nucleus of eukaryotes?
The DNA found in linear chromosomes of the nucleus of eukaryotes is tightly coiled and packaged with associated proteins called histones
What is a genome?
The sum total of all genetic material is the genome
What are chromosomes in eukaryotes contained within?
Chromosomes in eukaryotes are contained within a membrane bound nucleus
