DNA & the Genome Flashcards
All 7 cards in this deck
Describe the structure of a DNA molecule.
A polymer of two strands of nucleotides coiled together to form a double helix.
What three parts make up a DNA nucleotide?
A sugar and a phosphate group, with one of four different bases attached to the sugar.
What type of bond joins the base pairs holding the two DNA strands together?
Weak hydrogen bonds between complementary base pairs.
Which bases pair together in DNA?
e.g. one strand reads A–C–G
A pairs with T and C pairs with G, so the complementary strand reads T–G–C.
What is the difference between a gene and a genome?
A gene is a section of a DNA molecule that codes for a specific protein; the genome is the entire DNA of an organism.
What are the steps to extract DNA from fruit?
e.g. from a strawberry
- Mash the fruit and mix with salty water and detergent – detergent breaks down cell membranes, salt makes the DNA clump.
- Filter to remove the cell debris.
- Add ice-cold ethanol – the DNA is insoluble in it and appears as white strands.
True or false? DNA is a polymer.
True. It is a long chain made of many nucleotide monomers joined together.