4.1 DNA, Genes & Chromosomes Flashcards
(28 cards)
3 components of nucleotides.
A pentose sugar, a phosphate group, and an organic base.
What are the components that make up DNA?
Deoxyribose sugar, phosphate group, and one of four organic bases (A, C, G, T).
What is the structure of DNA?
Double-stranded
What type of bonds form the helix shape of DNA?
Hydrogen bonds between the bases.
Role of DNA.
Carries genetic information, determines our inherited characteristics.
What sugar is RNA made up of?
Ribose sugar
What are the components of RNA?
A ribose sugar, a phosphate group, and one of four organic bases (A, C, G, U)
Is RNA single stranded or double stranded?
Single stranded
What are the four organic bases found in RNA?
Adenine (A), Cytosine (C), Guanine (G), Uracil (U)
Role of RNA.
Transfers genetic information from DNA to ribosomes for protein synthesis.
Which bases are purine and which are pyrimidine?
Purine (double ring) = adenine, guanine.
Pyrimidine (single ring) = cytosine, thymine, uracil.
Where is DNA found in eukaryotic cells?
In the nucleus.
What is the structure of DNA in eukaryotic cells?
Long and linear
What proteins is eukaryotic DNA associated with to form chromosomes?
Histone proteins
What type of DNA do mitochondria and chloroplasts contain?
Prokaryotic-like DNA
Describe DNA in prokaryotic cells.
Short and circular. Not associated with proteins.
What is the genetic code?
The order of bases on DNA. Consists of codons (triplets of bases that code for a particular amino acid).
What does it mean that the genetic code is non-overlapping?
Each triplet is only read once.
What does it mean that the genetic code is degenerate?
More than one triplet codes for the same amino acid.
How many possible triplets are there in the genetic code?
64 possible triplets.
How many amino acids are coded by the genetic code?
20 amino acids.
What does it mean that the genetic code is universal?
The same bases and sequences are used by all species.
What is a gene?
A sequence of bases on a DNA molecule that codes for a specific sequence of amino acids to make a polypeptide. Can also code for functional RNA.
What is a locus?
The fixed position on a DNA molecule occupied by a gene.
