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DNA structure, DNA replication, and Protein Synthesis

Terms in this set (86)

What are the four nitrogenous bases that make up DNA?
Thymine (T), Adenine (A), Cytosine (C), Guanine (G)
The number of A bases are equal to the number of what other base?
T
The number of C bases are equal to the number of what other base?
G
What make up the rungs of DNA?
Complimentary nitrogenous bases (A and T, C and G)
What make up the sides of DNA (the backbone)?
Alternating sugars and phosphate groups
What does DNA stand for?
Deoxyribonucleic acid
What is the function of DNA?
Stores all the genetic information of an organism
What are nucleic acids made up of?
Nucleotides
What is the basic structure of a nucleotide?
Deoxyribose (sugar), phosphate group, nitrogenous base
What is the only difference between the four nucleotides that make up DNA?
The nitrogenous base
What are single ring structures called?
Pyrimidines
What two nitrogenous bases are pyrimidines?
Cytosine, thymine
What are double ring structures called?
Purines
What two nitrogenous bases are purines?
Guanine, adenine
What are nucleotides joined together by (making up the backbone of the DNA molecule)
Covalent bonds
Sugar of one nucleotide is covalently bonded to the _______________________ of another nucleotide.
Phosphate group
Nitrogenous bases (the rungs of the DNA molecule) are connected by what?
Hydrogen bonds
What determines which base pairs go together to form a rung in the DNA molecule?
Ability to form hydrogen bonds (which ones have opposite partial charges), size
What scientist that contributed to the discovery of DNA was trying to figure out why people got pneumonia?
Frederick Griffith (1928)
What did Frederick Griffith inject the different groups of mice in his experiment with?
Live rough pneumonia, live smooth pneumonia, heat-killed smooth pneumonia, heat-killed smooth pneumonia +live rough
When injected with live rough pneumonia, did the mice in Frederick Griffith's experiment survive?
Yes
When injected with live smooth pneumonia, did the mice in Frederick Griffith's experiment survive?
No
When injected with heat-killed smooth pneumonia, did the mice in Frederick Griffith's experiment survive?
Yes
When injected with heat-killed smooth pneumonia+live rough pneumonia, did the mice in Frederick Griffith's experiment survive? What happened that aided in the discovery of DNA?
No. Live R and S cells found, genetic material was transferred. (harmless R became the S)
What did Frederick Griffith hypothesize (that is incorrect) happened when the harmless R strain of pneumonia became the deadly S strain in his experiment?
R cells used S protein to make shells for themselves
Who investigated Frederick Griffith's discoveries?
Oswald Avery (1944)
What was the purpose of Oswald Avery's experiment?
To find out if DNA, RNA, or proteins were genetic material
How did Oswald Avery alter Frederick Griffith's experiment to discover what genetic material was?
Used enzymes to destroy, proteins, lipids, and RNA (transformation of R to S still occurred when live R and heat-killed S were injected). Then used enzymes to destroy DNA (transformation didn't occur).
What was the problem with Oswald Avery's conclusion that DNA stores and carries genetic information?
Proved once in one species
What scientists used viruses (bacteriophages) to figure out that DNA is not a protein?
Hershey and Chase (1952)
In Hershey's and Chase's experiment, what did he use to test for DNA?
Radioactive phosphorus
In Hershey's and Chase's experiment, what did he use to test for proteins?
Radioactive sulfur
After a virus infected a bacterium, what did Hershey and Chase find inside of it?
Radioactive phosphorus, part of the DNA (radioactive sulfur is part of protein coat. Used DNA to infect the bacterium, transfer the genetic information)
What scientists used x-ray crystallography when trying to discover DNA?
Maurice Wilkins and Rosalind Franklin (1953)
What did Maurice Wilkins and Rosalind Franklin discover from using x-ray crystallography?
DNA has a double helix shape
Who were the main scientists credited with discovering the structure of DNA?
Francis Crick and James Watson (1953)
What did Watson and Crick use in assistance to their discovery of the model of DNA?
Franklin's x-ray crystallography
What did Watson and Crick's model of DNA include?
Sugar-phosphate backbone, nitrogenous bases in the middle, strands connected by hydrogen bonds
The two DNA strands are _____________________.
Antiparallel
Why does DNA need to replicate?
Transfer genetic information on to the next generation
In cells, there are not only complete strands of DNA molecules but there are also _________________________________.
Free-floating nucleotides
The theory of DNA replication where the original DNA stays intact, free-floating nucleotides attach to the strands, copying it exactly, and peel off, making a new copy.
Conservative replication
The theory of DNA replication where the original DNA is unzipped by an enzyme, called helicase, free-nucleotides come and attach to the complementary nitrogenous base already on the DNA strand. Each new DNA molecule is 1/2 old and 1/2 new (made up of the free-floating nucleotides).
Semi-conservative replication
The theory of DNA replication where the original molecule breaks up into many pieces
Dispersive replication
The theory of DNA replication that results in more and more new molecule over time.
Dispersive replication
What is the first step in DNA replication?
Helicase (an enzyme) unzips the molecules (breaks hydrogen bonds between the corresponding nitrogenous bases, therefore breaking bonds connecting the two strands of DNA)
What experiment proved the semi-conservative replication theory was correct?
Meselson and Stahl's (1958)
What experiment grew bacteria in different environments with different isotopes of nitrogen and when switched (to the N14 environment), the results had DNA with a combination of the two nitrogens and ones with just the new isotopes (hybrid and light)
Meselson and Stahl's (1958)
Because of what characteristic of the strands of DNA can the nitrogenous bases caused hydrogen bonds?
They are antiparallel
What does 5' mean?
Carbon with phosphate
Where are the 5's on the DNA molecule?
Ending of leading strand, beginning of lagging strand
What does 3' mean?
Carbon with hydroxyl
Where are the 3's on the DNA molecule?
Beginning of leading strand, end of lagging strand
_____________ can only happen in 1 direction.
Replication
What get in the way of DNA polymerase from doing their job at the same time?
Phosphate group
What enzyme unzips the strand of DNA?
Helicase
What enzyme attaches free nucleotides to the correct corresponding nitrogenous base on the strand of DNA? This creates the new strand/side of DNA
DNA polymerase
The __________ strand is replicated continuously because it starts with a _____.
leading, 3' (hydroxyl group)
The ________ lagging strand is replicated discontinuously because it starts with a _____>
lagging, 5' (phosphate group)
On the _____________ strand, DNA polymerase directly follows the helicase.
leading
On the _____________ strand, DNA polymerase works in the opposite direction of the helicase. It is limited by how much the DNA has unwound. Once it is done, it circles around and starts over again. This creates _________________________.
lagging, okazaki fragments
What enzyme joins okazaki fragments together on the lagging strand?
DNA ligase
On the new strand of DNA, DNA polymerase and helicase work from _____ to _____.
5' to 3'
Why is DNA important?
It makes proteins
What three processes that allow genes to code for proteins are included in the Central Dogma?
Replication, Transcription, Translation
What is replication in terms of DNA, RNA, and proteins?
DNA to DNA
What is transcription in terms of DNA, RNA, and proteins?
DNA to RNA
What is translation in terms of DNA, RNA, and proteins?
RNA to protein
What does RNA stand for?
Ribonucleic Acid
What is the differences in sugars between DNA and RNA?
RNA uses ribose, DNA uses deoxyribose
What is the difference in nitrogenous bases between DNA and RNA?
RNA uses Uracil, DNA uses thymine
What is the difference in structure between DNA and RNA?
RNA is single-stranded, DNA is double-stranded
The enzyme that decodes the template strand of DNA for the mRNA to take it out of the cell
RNA polymerase
The process where RNA polymerase transcribes the sequence of DNA to the mRNA. The mRNA sequence is the opposite of the DNA template strand (the same as the coding strand but with U's instead of T's)
Transcription
The process of where mRNA takes the complementary sequence of the DNA template strand to the ribosome to be converted into proteins.
Translation
What are the functions of RNA?
Stores genetic information, transfers information to ribosomes for conversion into proteins
Areas in the DNA that tell RNA polymerase where to start
promoters
Areas in the DNA that tell RNA polymerase where to stop
terminators
a segment of DNA that contains the recipe ("code") for a particular polypeptide (protein)
Gene
the process that determines which proteins are made
Gene regulation
a specific DNA sequence to which a specific transcription factor binds
Regulatory sequence
molecules that find specific pieces of DNA to help/hinder RNA polymerase
Transcription factor
When a gene is transcribed and the mRNA is translated to make a protein
Gene expression
_____________ are composed of one DNA molecule (and some proteins)
Chromosomes
What do humans use mitosis for?
Replacement, repair, growth
Process that leads to cell division is called the:
Cell cycle
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