Nucleic Acids
What kind of molecule is a nucleic acid?
Macromolecule
Rosalind Franklin used X-ray diffraction to take photos of DNA that helps to determine its shape.
What does DNA stand for?
What is deoxyribonucleic?
Describe where DNA is found in prokaryotic and eukaryotic cells.
Eukaryotes - nucleus
Why is DNA replication a semi-conservative process?
When DNA replicates the original DNA is uses as a template to create the new DNA molecules so each new DNA molecule consists of one parent strand of DNA and one new strand of nucleotides.
What monomers make up nucleic acids?
Nucleotides
Describe how Erwin Chargaff contributed to the discovery of DNA.
Chargarff was a chemist that took samples of DNA from different species to determine the chemical makeup of DNA. He discovered that the amount of adenine always equaled thymine and the amount of cytosine always equaled guanine.
Describe the basic structure of DNA. (Do NOT include bonds.)
DNA is a double helix made of nucleotides. The uprights of the ladder consist of a sugar-phosphate backbone and the rungs of the ladder are made of nitrogen bases.
Eukaryotes - 1000x more DNA, # of chromosomes varies by species, linear
What is the role of DNA helicase?
What is breaks down hydrogen bond holding the two strands together?
Give 3 examples of nucleic acids
DNA, RNA, and ATP
How did Maurice Wilkins contributed to the discovery of DNA
Wilkins worked with Franklin and shared a photo of DNA taken by Franklin with Watson and Crick.
Identify where covalent bonds and hydrogen bonds are found in DNA.
Hydrogen bonds are weak interactions that join the nitrogen bases.
Describe the difference between chromatin and chromosomes.
Chromatin is thread-like DNA found when the cells is NOT dividing.
Chromosomes are condenses or coiled up DNA present when the cell is dividing.
What enzyme adds new nucleotides to the new strand of DNA?
DNA polymerase
Describe the function of DNA, RNA, and ATP.
DNA - stores genetic info
RNA - helps make proteins
ATP - provides cells with energy
How did Watson and Crick contribute to the discovery of DNA?
Watson and Crick built a model using the data obtained by Wilkins, Franklin, and Chargaff. The model showed DNA as a double helix consisting of a sugar-phosphate backbone with nitrogen bases complementary base pairing (A-T; C-G) to form the rungs of the ladder.
The DNA molecule is described as anti-parallel. What does this mean?
Compare and contrast a gene and a chromosome.
A gene is a sequence of nucleotides found on a chromosome that codes for a protein. Each chromosome contains many genes. Both chromosomes and genes are made of nucleotides.
A T T C G A C G C
T A A G C T G C G
Compare and contrast the structure of DNA, RNA, and ATP.
DNA is a double stranded molecule made of deoxyribose sugar and has the nitrogen bases A, T, C, G
RNA is a single stranded molecule made of ribose sugar and has the nitrogen bases A, U, C, G
ATP is a modified nucleotide made up of adenine, ribose and 3 phosphates
What is Chargaff's Rule?
Chargaff's rules state that in the DNA of any species and any organism, the amount of guanine should be equal to the amount of cytosine and the amount of adenine should be equal to the amount of thymine.
1. Stores genetic info - stored in sequence of nitrogen bases.
2. Passes genetic info to offspring. DNA can easily be unzipped and using complementary base pairing can copy the DNA to pass on to new cells/offspring.
3. DNA helps make proteins - stores the information for making proteins in the sequence of nucleotides and weak hydrogen bonds can easily be broken so RNA can copy the code for making the protein.
Explain why it is important for DNA to be able to condense into chromosomes.
Describe how the two strands of DNA are copied.
DNA polymerase will add new nucleotides to the leading strand of DNA that starts with a phosphate continuously.
On the lagging strand of DNA that starts with a sugar RNA primer must be added and then DNA nucleotides are added in short fragments between the RNA primers.