Biology Unit 6 Flashcards
Base triplets in mRNA strand
Codon
Any change in DNA
Mutation
Base sequence must be removed before translation
Intron
Contains that bases Adenine and Guanine
Purines
Gene variations that arise by mutation and exist at the same relative location on homologous chromosomes
Allele
Three-nucleotide sequence in a tRNA molecule that corresponds to an mRNA codon
Anticodon
Process through which messenger RNA forms on a template of DNA
Transcription
Physical and functional unit of heredity, a sequence of DNA that codes for a protein
Gene
Total gene information of a cell or organism
Genome
DNA sequence to which RNA polymerase and associated factors bind and initiate transcription
Promoter
DNA fragment that is synthesized in short stretch son the lagging strand
Okazaki Fragment
Set of all codons
Genetic Code
Nucleotides linked by covalent bonds
Phosphodiester
Mutation in which DNA sequence jumps into middle of Gene : these segments can turn on and off genes
Transposon
Making a mRNA molecule from the DNA Template
Translation
What is Chargaff’s Rule?
A=T
C=G
Why is the DNA molecule described as being antiparallel?
One strand runs 5’ to 3’ and the other runs 3’ to 5’
Describe the organization of a DNA nucleotide
Carbon atoms in sugar designated by numbers (1’ to 5’)
- Nitrogenous Base on 1’
- Hydroxyl Group on 3’
- Phosphate on 5’
Nucleotides form alternating sugar-phosphate backbone.
Compare and Contrast RNA and DNA
RNA : contains Ribose, single stranded, bases = ACGU : mRNA, tRNA, rRNA
DNA : polymer of nucleotides (deoxyribose, phosphate, and one of the four nitrogenous bases). : Base = purines and Pyrimidines : double helix (anti-parallel strand).
What are the Different Types of RNA? What are their Functions?
Messenger RNA : translation of RNA from Nucleus to ribosomes
Transfer RNA : carries amino acid triplet codes to the mRNA
Ribosome RNA : catalyst assembly of amino acids into protein chains.
What does it mean when the genetic code is described as redundant?
The genetic code is described as redundant which means it having more codons than amino acids.
DNA replication is described as semi-conservative. What does that word mean?
Bases on “old” strand join nucleotide to form “new” strand.
Distinguish between the terms leading strand and lagging strand. In your description, include the term Okasaki Fragments.
DNA replication occurs continuously only in the 5’ to 3’ direction (leading strand)
Replication can only occur discontinuously in the 3’ to 5’ (lagging strand)
-> short 5’ to 3’ stretches are added one at a time, which are Okasaki fragments
What are the enzymes that are involved in DNA replication? Describe the function of each enzyme.
DNA Polymerase : attach short stretches of nucleotides to unwound part of template
DNA ligase : fill in tiny gaps between new short stretches to form continous strand
DNA heliocase : unzips the DNA molecule into two pieces
Enzyme repair DNA where base-pairing errors have crept into nucleotide sequence.
