Ch.10 Molecular Biology Of The Gene Flashcards
Scientists manipulate ____ in the lab and use it to change the heritable characteristics of cells.
DNA
The study of heredity at the molecular level. Ushered in due to the breakthrough which established the role of DNA in heredity through experiments with bacteria and the viruses that infect them.
Molecular biology
Viruses that exclusively infect bacteria. Called phases for short.
Bacteriophage
Describe the phage replication cycle.
- The phage attaches itself to a bacterial cell.
- The phage injects it’s DNA into the bacterium.
- The phage DNA directs the host cell to make more phage DNA and proteins- new phases assemble.
- The cell loses and releases the new phages.
What convinced Hershey and Chase that DNA, rather than protein, is the genetic material of phage T2?
Radioactivity labeled phage DNA, but not labeled protein entered the host cell during infection and directed the synthesis of new viruses.
Long chains (polymers) of chemical units (monomers).
Nucleotides
Nucleotide polymer chain constituting a section of nucleic acid molecule.
Polynucleotide
Each type of DNA has a different nitrogen containing base what 4 are they.
Adenine (A)
Cytosine (C)
Thymine (T)
Guanine (G)
The number of possible polynucleotides is enormous because of what 2 reasons?
- Nucleotides can occur in a polynucleotide in any sequence
2. Polynucleotides can be very long.
Each nucleotide consists of what 3 components.
- A nitrogenous base
- A sugar
- A phosphate group
Nucleotides are joined together by which type of bond between the sugar of one nucleotide and phosphate of the next forming a sugar-phosphate backbone.
Covalent bond
This is a repeating pattern of sugar-phosphate-sugar-phosphate, in which nitrogenous bases are like ribs that project from this backbone.
Sugar-phosphate backbone
What is the full name of DNA?
Deoxyribonucleic Acid
What does the nucleic part of DNA stand for?
Nucleic refers to the location in the nucleic eukaryotic cells.
This is the name given to Thymine and Cytosine in single ring structures.
Pyrimidines
This is the name given to Adenine and Guanine in larger doubling structures.
Purines
What is the full name of RNA?
Ribonucleic Acid
RNAs sugar is ribose with a _____ group attached to a C atom.
-OH group
Instead of Thymine, RNA has a _____ nucleotide.
Uracil (U)
RNA is identical to a DNA polynucleotide chain except for what two differences?
RNA has Uracil instead of thymine
RNA sugar is ribose.
The DNA double strand helix was discovered by whome?
James D. Watson and Francis Clark
What is a double helix?
Two polynucleotide strands
A double ringed base (purine) on one strand must always be paired with what?
A single ringed base (pyrimidine) on the opposite strand to produce a molecule of uniform thickness.
Each nitrogenous DNA base has a protruding functional group that can best form hydrogen bond with just one appropriate/complimentary partner, what are they?
Adenine with Thymine
Guanine with Cytosine
Chargraffs rule states what?
That adenine in DNA of any one species is equal to the amount of thymine, guanine is equal to the amount of cytosine.
The side ropes of the double helix represent what? The rungs?
Side ropes- represent the sugar phosphate group
Rungs- represent pairs of nitrogenous bases joined by H bonds.
DNA replication depends on what?
Specific base pairing
One can determine the sequence of bases in the covered strand by applying the ___ ____ ____ to the unmasked strand.
base-pairing rules
This predicted that a cell applies the same rules when copying its genes during each turn of the cell cycle.
Base-pairing rules
Each strand becomes a template for the assembly of a complementary strand from a supply of ____ ____ available with in the nucleus.
Free Nucleotides
____ link the nucleotides to form new DNA strands.
Enzymes
Type of DNA replication in which the replicated double helix consists of an old strand derived from the old molecule and one newly made strand.
Semiconservative model
Replication of a DNA molecule begins at particular sites called what?
Origins of replication
What are origins of replication?
Short stretches of DNA having a specific sequence of nucleotides.
Proteins that initiate DNA replication attach to DNA at _____ separating the two strands of the double helix.
Origin of replication
DNA replication proceeds in ____ direction at many sites simultaneously.
two
These are the enzymes that link DNA nucleotides to a growing daughter strand. They add nucleotides only to the 3’ end of the strand and never the 5’ end.
DNA polymerases
DNA strand can only grow in the ____ direction.
5’-3’
To make another daughter strand polymerase molecules must work outward from the ____ point.
forking
These are short newly synthesized DNA fragments that are formed during DNA replication.
Okazaki fragments
This links pieces of okazaki fragments together into a single DNA strand.
DNA ligase
These “proofread” and remove nucleotides that have base paired incorrectly.
DNA polymerase
These repair DNA damaged by radiation.
DNA ligase
DNA replication ensure that all of the somatic cells in a mulitcellular organism are what?
Carry the same genetic information
Genes control phenotype traits through the expression of___.
Proteins
This is genetic makeup that is heritable information contained in the sequence of nucleotide bases in DNA.
Genotype
Physical traits are called?
Phenotype
These are the links between genotypes and phenotypes. DNA inherited by an organism specifies traits by dictating the synthesis of these.
Proteins
The synthesis of RNA under the direction of DNA is called?
Transcription
The synthesis of protein under the direction of RNA is called?
Translation
What is the flow of genetic information in eukaryotic cells?
DNA—transcription—RNA—Translation—proteins
Transcription occurs within the nucleus
Translation occurs within the cytoplasm.
What is the function of a gene?
To dictate the production of a polypeptide.
This is the process of eukaryotic genes coding for a set of polypeptides.
Alternative splicing.
What are the functions of transcription and translation?
Transcription is the transfer of information from DNA ro RNA. Translation is the use of the information in RNA to make a polypeptide.
Genetic information written in ____ is translated into amino acids.
Codons
____ provide the instructions for making specific proteins
Genes
___ is the bridge between DNA and protein synthesis.
RNA
The genetic code instructions for the amino acid sequence of a polypeptide chain, written in DNA and RNA as a series of non-overlapping three-base words.
Triplet code
The series of non overlapping three base words are called?
Codon