Exam 3 Flashcards
Monomer of DNA?
Nucleotides
What are Pyrimidines and give examples?
Nitrogenous base with one ring
C (cytosine)
T (Thymine)
What are purines and give examples?
Nitrogenous bases with 2 rings
A (adenine)
G (guanine)
Describe the structure of a DNA
Nitrogenous base (A,T,G,C)
Deoxyribose Sugar
Phosphate group
The backbone of dna is the _____
Sugar-phosphate backbone
What is found at the 5’ end and the 3’ end?
5’: Phosphate group
3’: OH-
What are the nitrogenous base pairings?
Adenine & Thymine
Guanine & Cytosine
Nitrogenous bases in DNA vs RNA
RNA swaps the Thymine in DNA for Uracil
DNA - A, T, G, C
RNA - A, U, G, C
The sugar in DNA is _______
deoxyribose
The sugar in RNA is _______
ribose
How are the nitrogenous bases connected within the double helix?
Hydrogen bonds
Describe mRNA
Messenger RNA
Translates DNA into form readable for cells. (T —> U)
Describe rRNA
Ribosomal RNA
Helps mRNA bind to a spot on ribosome
RNA that acts as enzyme is called _______
Ribozymes
Describe tRNA
Transfer RNA
Brings amino acids to ribosome and ensures it is the amino acid specified by mRNA
How do regulatory mRNA (miRNA & siRNA) maintain homeostasis?
Bind to mRNA molecules and reduce their stability or interfere with the translation
Topoisomers function
Prevents supercoiling
Prevents double helix from getting to tightly wound as it is being opened
Helicase function
Breaks the hydrogen bonds that bind the nitrogenous bases in DNA.
Splits the DNA.
Function of RNA Primer
What’s synthesizes primer?
Begins the synthesis of DNA strands
-Primase
What is DNA polymerase?
Enzyme that creates new DNA by adding nucleotides to growing DNA chain
In what direction do nucleotides get added?
5’ —-> 3’
What is the replication fork?
The Y-shape created by the splitting of the DNA helix