Structure of DNA (KA1)

Key area 1

Name the units of DNA

Nucleotide

What types of bond formed between bases

hydrogen bonds

Name the protein the help stores chromosomes inside a nucleus

Histones

Name given to additional DNA mainly found in bacteria cells

Plasmids

Why is yeast considered a special example of a eukaryotic

It contains plasmids

A DNA nucleotide contains three components.

State the three components

Deoxyribose sugar, phosphate, base

Name the type of bond that holds the paired bases together

Weak hydrogen bonds

Name the molecule present at the 5’ ends of a DNA strand

Phosphate

State two features of the organisation of DNA in a prokaryotic cell

Single circular chromosomes in the cytoplasm and additional circular DNA call plasmids

What are the examples of the cells in PROKARYOTIC

Bacteria

What are the examples of the cells in EUKARYOTIC

Plant, animal and fungal

Compare one different in the organisation of DNA in prokaryotic and eukaryotic cells

Eukaryotes have a linear chromosomes whereas prokaryotes have a single circular chromosome

State one location, other than the nucleus, where DNA can be

found in a eukaryotic cell

Mitochondria

How are nucleotides joined together within a single strand of DNA

The sugar phosphate backbone

Describe the arrangement of a DNA molecule.

Two strands of DNA nucleotides which are antiparallel. One strand runs in a 5’ to 3’ direction and the other strand runs in a 3’ to 5’ direction