Gene Action Flashcards
What does DNA stand for?
Deoxyribose nucleic acid
Describe the shape of the DNA molecule. What is this called?
Ladder shape, two strands of nucleotides twisted around each other, double helix, discovered by Watson and Crick
What are nucleotides?
Units that make up DNA: 3 parts- sugar group, phosphate group, nitrogen base
What types of bonds are between the nucleotides?
Strong covalent bonds
What types of bonds are between the two strands?
Weak hydrogen bonds
Why can only certain bases bond? What is this called?
Depending on the number of hydrogen bonds, complementary base pairings
Give the complementary base pairs of DNA
Guanine ; Cytosine
Adenine ; Thymine
What is the function of DNA?
Carries the code (spelled out in the order of the bases) to make all the proteins that make up and control your body
Give some examples of how DNA controls who/ what you are
DNA carries the genes that determine our genotype. The expression of your genotype is your phenotype - what you look like, etc..
Where in the DNA is the code to form the proteins? What will result if this is mistaken?
The code is in the order of the bases on the DNA. If a base is wrong, this can result in an incorrect amino acid being added to the protein, which may or may not cause the protein to work correctly
What is replication of DNA? What results?
Replication is copying DNA. The result is an exact copy of the original DNA
What cell process is replication essential for? Why?
Cell division (mitosis and meiosis) because each resulting daughter cell needs its own copy of DNA
Give a step by step explanation of the replication of DNA. What ensures that the copies will be exact?
DNA unzips down the middle between bases, new nucleotides come in and match the old bases by complementary base pairing, two exact duplicate strands of DNA form
What is RNA used for? Compare and contrast RNA and DNA.
DNA- Shape=2 strands, Location= nucleus, Bases= thymine, Sugar= deoxyribose
RNA- Shape= 1 strand, Location= cytoplasm, Bases= uracil, Sugar= ribose
List and give functions for the 3 types of RNA molecules
mRNA- cheap copy of DNA code that can come out of the nucleus
tRNA- brings in the amino acids in the correct order to make the protein
rRNA- on the ribosomes, manages the bonding of the amino acids together into proteins
What is protein synthesis?
using coded information (bases) on DNA to make specific proteins
What are the two steps of protein synthesis?
Transcription and translation
Briefly describe what occurs in transcription. Where does this occur?
Code is copied from DNA to mRNA by complementary base pairing in the nucleus
Briefly describe what occurs in translation
Amino acids are put together in the correct order as specified by the mRNA
Where does translation occur?
On the ribosomes on the cytoplasm
What molecule is the mRNA copied off of? How is this done?
DNA in the nucleus is the template mRNA formed with codons, mRNA moves to ribosomes in cytoplasm
What molecule must the tRNA fit on to?
as tRNA leaves the polypeptide chain is transferred to the newly arrived tRNA
What is a codon?
mRNA’s 3 bases
What is an anti-codon?
tRNA’s 3 matching bases
What must a codon and anti-codon be to each other?
They must match so the amino acid is correct
How does the code ensure that each amino acid will be put in the correct spot in the protein?
Through complimentary base pairing; DNA is the template to make mRNA; tRNA must be complementary to mRNA
Start fro the DNA and explain how a mistake in the code can get passed on to en up a mistake in the protein. What is this called?
A mistake in the DNA such as substitution (wrong base) or deletion/addition (base missing or extra one added) will cause the wrong amino acid to be bonded into a protein. The protein may still work, or it may not. A mistake in the genetic code is called a mutation
How many differences in the code must you have to get sickle-cell disease? What protein is replaced and with what in the code?
Glutamine is replaced with valine
What is gene therapy and how is it used?
Introducing genetically engineered human cells into a human body for the purpose of curing a genetic defect
What is genetic engineering?
A process designed to artificially control the genetic makeup of an organism
How are trans genetic bacteria made? What are they used for? What is the advantage?
DNA is taken out of one of the species and put into the bacteria to make them do something specific for us like make insulin
Transcribe this sequence of DNA to mRNA:
AGTCACGTC
UCAGUGCAG
