DNA/RNA Structure Flashcards
The two types of Nucleic Acids
DNA & RNA
Components of Nucleic acids
Both DNA and RNA are made of nucleotides, which consist of:
A phosphate group
A pentose (5-carbon) sugar (deoxyribose in DNA and ribose in RNA)
A base
Whos study outlined that base sequences had variation
Chargaff
Which bases are pairs in DNA
A-T
&
C-G
A Dna strand is
A single strand of dna nucelotides linked 5->3
A DNA molecule is
A full complete double helix of Dna base pairs
DNA and RNA stands are synthesised in the ______ direction
a )2-5
b) 3-5
c) 5-3
d) 5-2
c) 5-3
C-G How many hydrogen bonds
3
A-T How many hyddrogen bonds
2
When two strand of DNA link do they connect Parallel of Antiparallel?
Antiparallel
Are A-T & C-G are complementary to each other
Yes
Why do cells replicate DNA
Because body needs to creat new cells
eg. Pregnancy, Injury, growing in life.
What is the structure of RNA?
RNA is single-stranded and made up of ribonucleotides with ribose sugar. It has the nitrogenous bases Adenine (A), Uracil (U), Cytosine (C), and Guanine (G).
Which Base in DNA is replicated with U (Uracil) in RNA
T (thymine)
What is the function of DNA?
DNA stores and transmits genetic information and serves as a blueprint for protein synthesis.
What is the function of RNA?
RNA is involved in protein synthesis (mRNA, tRNA, rRNA) and acts as a messenger carrying genetic information from DNA to ribosomes.
Where is RNA located in cells?
RNA is found in both the nucleus and the cytoplasm
The ‘Adaptor’ Molecule
An enzyme recognises both a
specific _____ and the
correct ____ for an amino acid
and joins them together
-Amino acid
-tRNA
How many start Codons, and name(s)?
1
(AUG - this codon also specifies methionine)
How many Stop Codons and their name(s)
3
UAA – Ochre
UAG – Amber
UGA – Opal (or Umber)
Initation stage in Translation (DNA replication)
Initiator tRNA (carrying methionine) binds to the binding small ribsomal binding site.
The complex identifies the 5’ G-cap on mRNA and attaches.
It moves along mRNA (5’ → 3’) until finding the AUG start codon.
The initiator tRNA positions methionine in the P site.
The large ribosomal subunit attaches, completing the ribosome assembly.
Elongation Stage in Translation
A new tRNA carrying an amino acid enters the A site of the ribosome.
The ribosome catalyzes peptide bond formation between the amino acid in the P site and the new amino acid in the A site.
The ribosome moves along the mRNA (5’ → 3’), shifting the tRNA from the A site to the P site.
The empty tRNA exits from the E site, and the process repeats as new tRNAs bring amino acids
Termination Stage in Translation
The ribosome reaches a stop codon (UAA, UAG, or UGA) on the mRNA.
A release factor binds to the stop codon in the A site instead of a tRNA.
The ribosome catalyzes the release of the polypeptide chain from the tRNA in the P site.
The ribosomal subunits, mRNA, and release factors dissociate, completing translation.
In termination (Translation) what is the Protein that stops and releases the mRNA
Release Factor
(Anika said it looks like a urinated tampon)
