DNA and RNA Flashcards
What does DNA stand for?
Deoxyribose nucleic acid
What does DNA do?
Stores genetic infomation
What does RNA stand for?
Ribonucleic acid
What does RNA do?
Transfer genetic information from DNA ribosomes
What makes up a nucleotide?
Phosphate
Pentose sugar
Base
What is the pentose sugar and bases in DNA?
Pentose sugar: deoxyribose
Base: A,T,G,C
What is the pentose sugar and bases in RNA?
Pentose sugar: ribose
Base: A,U,G,C
Name the 3 types of RNA
Messenger
Ribosomal
Transfer
Describe messenger RNA
Single stranded copy of a gene, which is produced through transcription and translation
Describe ribosomal RNA
Part of transcription. Decides what the structure of ribosomes will look like and it is responsible for catalytic activity
Describe transfer RNA
Part of transcription. Transfers amino acids to ribosomes and reads mRNA. Tertiary structure and hydrogen bonds
What is a polynucleotide?
Polymer of nucleotides
How are nucleotides joined together?
Via a condensation reaction between phosphate and sugar (sugar-phosphate back bone)
What bond is formed when nucleotides join together?
Phosphodiester bonds
What is the name of the structure when 2 polypeptides join together?
Double helix structure (hydrogen bonding)
Name the complementary base pairing and state how many hydrogen bonds join them
A and T = 2 bonds
C and G = 3 bonds
What did Meselson and Stahl show?
They showed that DNA is replicated using the semi-conservative method
Explain the semi-conservative method of DNA replication
- DNA helicase (enzyme) breaks the hydrogen bonds. The helix unwinds to form 2 single strands.
- Strand acts as template for complementary base pairing to occur. Free floating nucleotides are attracted to complementary exposed bases on template strand.
- A condensation reaction joins the nucleotides together. This reaction is catalysed by DNA polymerase and hydrogen binds form.
- A new DNA molecule is formed with 1 original strand and 1 new strand.
