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What are mistakes in copying DNA called?
Mutations
What are the 2 types of mutations?
chromosomal mutations and gene mutations
What are the 2 types of gene mutations?
Point mutation and frameshift mutation
What are the types of point mutations?
substitutions, insertions, and deletions
What is a Point Substitution mutation?
Replacement of one nucleotide and its base pair with another
What is a point mutation?
Mutation only affecting a single point on the DNA sequence
What is a chromosomal mutation?
A mutation that effects the whole chromosme
What is a gene mutation?
Mutations that change a single gene
What are the different types of substitution point mutations?
silent, nonsense, missense
What is a silent mutation?
Alters the codon but not the amino acid that's produced
What is a nonsense mutation?
produces a stop codon prematurely
What is an insertion point mutation?
an extra base is added to the sequence
What is a deletion point mutation?
a single base is deleted
What are insertion and deletion point mutations classified as?
frameshift mutations
What is a deletion (chromosomal)?
removes a chromosomal segment or the whole chromosome
What are the 4 types of chromosomal mutations?
deletion, duplication, inversion, and translocation
What is a chromosomal deletion mutation?
loss of all or part of a chromosome
What is a chromosomal duplication mutation?
produces extra copies or parts of a chromosome
What is a chromosomal inversion mutation?
reverses the direction of parts of a chromosome
What is a chromosomal translocation mutation?
where a segment of a chromosome breaks off and attaches to another
What is a polyploidy?
The condition in which an organism has extra sets of chromosomes but is not considered a mutation
What is a gene regulation?
the turning on or off of genes (a gene that is being transcribed)
What are the components of gene regulation in a prokaryotic cell?
promotors, operators, and operons
What is a promotor?
segment of DNA that allows RNA polymerase to attach to it and begin transcription
What is the operator?
DNA segment that turns a gene on or off
What is an operon?
DNA that includes a promoter, operator, and one or more genes that code for all proteins needed to do specific tasks
What is a repressor?
a protein that binds to the operator and physically blocks RNA polymerase from carrying out transcription
What is an inducer?
binds to a repressor so it will detach from the operator and RNA polymerase can continue transcription
How do eukaryotic cells control gene regulation?
Transcription factors
What makes eukaryotes different from porkaryotes in transcription?
They do not have an operator or inducers, they have TFs
What is histone acetylation?
acetyl groups are attached to lysines in histone tails which loosens the chromatin structure and promoting transcription
What are hox genes?
Series of genes that control differentiation
What do hox genes do?
Start a chain reaction that turns genes on or off
What is Differentiation?
The process by which a cell changes to become specialised for its job
What does DNA control?
The production of proteins
What is transcription?
The process of copying a gene in DNA to mRNA
What does mRNA contain?
Coded information for making proteins
What is RNA made up of?
Nucleotides
What are the 3 differences between DNA and RNA?
1. The sugar in RNA is ribose instead of deoxyribose
2. RNA is single-stranded
3. Rna contains uracil in the place of thymine
3 multiple choice options
What is RNA's main function?
Synthesise proteins
What are the 4 types of RNA?
mRNA, rRNA, tRNA, and Aminoacytal-tRNA
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What does mRNA carry?
Copies of instructions for assembling amino acids into proteins
What is ribosomal RNA (rRNA)?
Forms parts of a ribosome that helps translate the information in mRNA into proteins
What contains the genes that code for rRNA?
Nucleolus
What does tRNA do?
Carries an amino acid to the ribosome to transfer it to the ribosome
What does transcription requre?
RNA Polymerase
What does the RNA Polymerase add?
nucleotides
Where does RNA Polymerase bind at?
Single point on DNA strand called a promoter that signals the enzyme where to bind to make RNA
What does RNA Polymerase do once its binded with the promoter
It starts to separate the DNA
What does RNA Polymerase do after it separates the DNA?
Use one strand (of the 2 separated) as the template) and will add nucleotides into a strand of RNA
What is mRNA fresh out of transcription called and what needs to happen to it?
Called Pre-mRNA and needs to be edited because it is like a cut of a movie (that is out of order)
Where are helicases and polymerases used?
Helicase is only used in DNA, while Polymerase is used in both DNA and RNA but separates and adds in RNA
What is the purpose of the cap on mRNA?
Signals the nuclear pores to allow the mRNA to leave, helps the strand bind to a ribosome, and prevents it from being broken down
3 multiple choice options
What is the final sequence of mRNA called?
Tail
What are the parts of Pre-mRNA that are not needed?
Introns
What are the nucleotide code segments that are kept and code for proteins called?
Exons
What are Exons and Introns separated by?
snRNPs (small nuclear ribonucleoproteins)
What is a spliceosome?
A group of snRNPs that shoves out introns and pushes exons together
What are codons?
3-nucleotide sequence
Where are codons found?
Only in mRNA
For one codon, what is there?
One amino acid
What are start codons?
Signal the code to start translation for the same codon is for the AA methionine
What are stop codons?
At the end of the chain and signal AA production to stop
What is the reading frame?
the order in which nucleotides are read
What 2 items are needed to translate mRNA?
Translation machine (ribosome) and tRNA
What are the 2 subunits of ribosomes?
large and small
What does the large and small subunits hold onto?
Large - growing protein, Small - mRNA
What is on the opposite side of the amino acid of tRNA?
Anticodon
What is Aminoacyl-tRNA synthase?
Enzyme that adds amino acids to an empty tRNA
What is the first step of Translation?
Small ribosomal subunit binds to an mRNA strand in the cytoplasm
What is the 2nd step of Translation?
tRNA attaches to AUG start codon
What is the 3rd step of Translation?
The binding signals a large ribosomal subunit to join
What is the 4th step of Translation?
The ribosome pulls the mRNA through one codon at a time
What is the 5th step of Translation?
The exposed nucleotides matches a complementary tRNA
What is the 6th step of Translation?
The tRNA anticodon pairs with the mRNA codon
What is the 7th step of Translation?
The ribosome helps form a peptide bond between the 2 amino acids
What is the 8th step of Translation?
The amino acid chain is transferred over from the P to A site
What is the 9th step of Translation?
The ribosome pulls the mRNA strand one codon over
What is the 10th step of Translation?
The tRNA in the 2nd site/"p" now moves to the 3rd site "e"
What is the 11th step of Translation?
Once the tRNA is in the "e" site it exits the ribosome
What is the 12th step of Translation?
Process continues until the ribosome reaches the stop codin
What does DNA stand for?
deoxyribonucleic acid
Where in a cell is DNA found?
Nucleus (eukaryotic)
Cytoplasm (prokaryotic)
What is the difference between chromatin and chromosomes?
Chromatin is seperate and Chromsomes are together.
How many pairs of chromosomes does a human have in their skin cells?
46
What is a segment of DNA that codes for a protein called?
Gene
What are the 3 parts of a nucleotide?
Nitrogen base, Sugar, Phosphate
What 4 bases make up DNA Molecules?
Adenine, Thymine, Guanine, Cytosine
What is the shape of a DNA molecule?
Double helix
What type of bond holds together nitrogen bases?
Hydrogen bond
How many hydrogen bonds are found between A-T?
2
How many hydrogen bonds are found between C-G?
3
What scientists are credited with the "base-pairing" rules?
Watson and Crick
What are the base pairing rules?
A-T, G-C
What is the importance of the order of base pairs in a DNA molecule? (Why cant A join with G or T with C?)
If 2 of the same families are paired with one another, a mutation will form.
When does DNA replicate?
S phase
What does the order of nitrogen bases determine?
The type of protein that is assembled
What are the 2 observations that griffith made?
Disease causing pneumonia had smooth edges while the harmless strain had rough edges
What was the first experiment griffith set up?
He injected mice with the disease causing strain and it killed the mice
What does virulent mean?
disease causing
