Molecular Genetics SG Flashcards
Mutation Replication transcription and translation
Differences in Dna
Double stranded, deoxyribose, thymine, exact copy
Differences in rna
Single strand, ribose, uracil, more than one form
Replication
Where DNA is copied
Transcription
DNA to RNA
Translation
RNA to protein
Purine nitrogen bases
Adenine and guanine
Pyrimidine nitrogen bases
Thymine and cytosine
Difference between purines and pyrimidines
Purines have a two ring structure. Pyrimidines have a one ring structure.
What is the monomer for nucleic acid?
Nucleotides
What is the monomer for proteins?
Amino acids
What is the primary function or purpose for DNA?
Store genetic information for an organism
Where does DNA replication take place?
Nucleus
Where does transcription take place?
Nucleus
Where does translation take place?
Ribosome
What are the three parts to a nucleotide?
Sugar, phosphate group, nitrogen base
What two enzymes are involved in replication?
DNA helicase and DNA polymerase
What enzyme is involved in transcription?
RNA polymerase
Which nitrogen base is an RNA but not DNA
Uracil
A group of three nitrogen bases on an mRNA strand
Codon
A group of three nitrogen bases on a TRNA strand
Anticodon
How many amino acids are commonly found in organisms
About 20
What type of bond is between the nitrogen bases?
Hydrogen bonds
What type of bond is between the sugar phosphate, backbone of DNA?
Phosphodiester
Mutation
A change within a nucleus acid that can harm or benefit the organism
What is a polymer?
Large molecules made from multiple monomers
What does dna stand for?
Deoxyribonucleic acid
What are the monomers of dna?
A nucleotide
What are the three components of a nucleotide?
Sugar, phosphate group, and nitrogenous base
What is the shape of a DNA molecule?
Double helix
Who discovered the shape of dna?
James Watson and Francis crick
How did Wilkins and Franklin contribute to the discovery of DNA structures?
Franklins images allowed Watson, and crick to create the discovery. Or x-rays of models
What are the four nitrogenous bases?
Adenine thymine guanine and cytosine
Which bases are complementary?
Adenine with Thymine
Cytosine and Guanine
What type of bond holds bases together?
Hydrogen bonds
What two bases are purines?
Adenine and guanine
What do bases are pyrimidines?
Thymine and cytosine
Describe the double helix, (what makes up the backbone in the rungs)
Deoxyribose Sugars and phosphate groups
How does DNA replicate?
DNA replication
What enzyme unzips the double helix
DNA helicase
What is DNA polymerase?
Reads broken DNA and builds two new strands with complementary bases
What is the complementary DNA sequence? ATTGCAGAT?
TAACGTCTA
If a DNA molecule is 20% adenine what is the percentages of T C and G
T 20
C and G 30
Why is DNA replication considered semi conservative?
Half of the parent DNA molecule is conserved in the two daughter dna molecules
What does antiparallel mean?
If two biopolymers run parallel to each other opposite directionally (alignment)
What does RNA stand for?
Ribonucleic acid
What are the three types of RNA
mRna rRNA tRNA
Copies, genetic instructions from DNA and carries it to the cytoplasm
mRNA
Helps form ribosomes, the organelle, where proteins Are assembled
rRNA
Brings amino acids to ribosomes, to form proteins
tRNA
What is the five carbon sugar in RNA?
Ribose
What are the four RNA bases?
Adenine
Uracil
Cytosine
Guanine
Given the following sequence, what’s the complementary mRNA sequence TATGCAATCGAC
AUACGUUAGCUG
List three ways RNA different from DNA
Uracil
Single stranded
Ribose
What is transcription
information in DNA is transcribed into a smaller version of RNA
What is needed for transcription
RNA polymerase, transcription factors (proteins)
What are the steps of transcription?
Initiation
Elongation
Termination
Transcription stage one
RNA polymerase binds to the promoter, signals DNA to unwind so the enzyme can read the bases
Transcription stage two
, reads the unbound DNA strands and builds the mRNA molecule using complementary base pairs.
Transcription stage three
RNA polymerase crosses a stop termination sequence and detaches from DNA.
Where does transcription occur?
Nucleus
What is the primary transcription enzyme
RNA polymerase
What terminates transcription
When RNA polymerase reaches the stop terminaton sequence
What is the genetic code?*
Nucleotides called codons
What is a codon
Sequence of three DNA or RNA nucleotides that goes with an amino acid
What does a triplet code refer to
64 different combinations (4x4x4) genetic codeor a sequence of 3 nucleotides
What is translation
When the genetic code in mRNA reads one codon at a time to make proteins
What is the start signal for translation
Code AUG FOR RNA
TAC. FOR DNA
What amino acid does AUG code for
Methionine
What is the function of tRNA in translation
Carrying specific animo acids to ribosome to build proteins
Where are the amino acids found in the cell?
Ribosome
What is an anticodon
A sequence of three bases, complementary to the codon
What type of covalent bond hold amino acids together
Peptide bonds
Where does translation occur
Ribosome
Translation stage 1
Ribosome Attaches to mRNA
Translation stage 2
Ribosome starts reading code
Translation stage 3
tRNA carrying an amino acid binds anti-codon to codon on mRNA
Translation stage 4
Bonds form between amino acids in a polypeptide chain grows
Translation stage 5
Translation stops when the ribosome reaches a stop codon