DNA/PS/Genetics Flashcards
What does five prime and three prime referred to?
Sugar molecules are oriented differently. Carbon Atoms in sugar are numbered; five carbon atom(5’) is uppermost on the left strand, three Carbon Atom(3’) is attached to the phosphate which is uppermost on the right strand.
Name the four bases in DNA and describe the structure of DNA
- Cytosine} pyrimidine
- Thymine } pyrimidine
- Adenine- } purine
- Guanine-} purine
DNA is a double helix. it has a five carbon sugar and phosphate group backbone. the rungs of the latter are the nitrogenous bases. 5’(prime) and 3’(prime) refers to the fact that DNA strands are antiparallel, which means they run in opposite directions.
Describe the steps involved in DNA replication.
- Before replication begins, the two strands that make up parental DNA are hydrogen bonded to one another.
- DNA helicase unzips the DNA by breaking the weak hydrogen bonds
- DNA polymerase adds new complementary nucleotides to the two single strands of DNA.
- complementary base pairs Ensure that there are no mistakes. the complementary base pairs are a AT, GC
- DNA is anti-parallel. This means that it’s outer structures are opposite each other. On the left the five prime sugar is pointing upwards ; right the three prime is pointing upwards
What does semi conservative mean?
One of the parental strands is conserved or present in each new double helix.
Describe three uses for recombinant DNA. List the dangers with the use of this technology.
1.inserting the human insulin gene into E. coli, which then produces insulin for human use
2. Protein factor VIII produced for hemophiliacs
3. injecting virus that has the DNA to reproduce bone cells into bones to treat bone marrow disease
Dangers: safety concerns(virus gaining resistance)
What are the structural differences between DNA and RNA?
RNA-> single strand; uracil instead of thymine; ribose
DNA-> double helix; thymine; deoxyribose
Functional differences between DNA and RNA?
DNA is the blueprint, RNA is responsible for copying the DNA and making proteins with it.
What are the basic steps of protein synthesis? Identify the role of DNA, mRNA, tRNA and ribosomes in the processes of transcription and translation. Include in your discussion transcriptase, tRNA, codon, anti-codon, polypeptide.
- Transcription: in the nucleus; transcriptase AKA RNA polymerase adds new nucleotides &proof reads
- 3 bases= a codon eg(TCA) eventually becomes AA - mRNA goes out the nuclear pore and to the ribosome.
- Translation: 2 bonding sites on the ribosome. tRNA brings a specific AA; codon matches w/ anti-codon; codon language changes to AA language; ribosome moves along the mRNA 1 codon at a time.
What causes mutations in humans?
Drugs; chemicals; and radiation.
How do mutations in DNA affect protein synthesis and lead to genetic disorders?
A mutation will change the codon which in turn changes all of the codons after that, changing the way the anti codons and codons will combine.
What is the difference between a chromosomal mutation and a gene point mutation
A chromosomal mutation is a mutation that occurs during meiosis. There are four types: inversion; translocation; deletion; and duplication.
A gene or point mutation involves only a few nucleotides within a gene. It is usually more serious than a chromosomal mutation. There are three types deletion; substitution; and addition.
What is deletion in a gene mutation? in a new chromosomal mutation?
- In a chromosomal mutation, deletion is the loss of a piece of the chromosome
- In gene mutations deletion occurs when a nucleotide is left out, it may cause a nonfunctioning proteins
What is inversion in a chromosomal mutation?
A piece of the chromosome breaks off and joins in the wrong order
What is translocation in a chromosomal mutation?
-Translocation is the exchange of a piece between non-partner chromosomes
What is duplication in a chromosomal mutation?
Duplication occurs when a piece gets copied.
