N5S3 - DNA Structure - 1.6 Flashcards
Describe the structure of DNA
Double stranded helix held together by complementary base pairs
Define the purpose of DNA
DNA carries the genetic information for making proteins
Where is DNA stored?
Inside the nucleus of the cell in chromosomes
State the four bases and their complementary base pairs
BASES
* Adenine
* Thymime
* Guanine
* Cytosine
COMPLEMENTARY BASES
* Adenine always pairs with Thymine
* Guanine always pairs with Cytosine
Define the genetic code
It is the sequence of bases along a strand.
What does the base sequence determine?
The amino acid sequence in proteins.
Define a gene
A gene is a section of DNA that codes for a protein
What are the two strands in DNA held together by?
Weak hydrogen bonds
What is a chromosome?
A chromosome is DNA that is stored as long thin threads.
What is the name of the hundreds of repeating units that make up DNA strands?
Nucleotide bases
How many pairs of chromosomes do humans have?
23 (46 in total)