lecture 9 Flashcards
Dna stands for
Stands for deoxyribonucleic acid
What is DNA
- The genetic material of all cells
- Can be described as a sugar-phosphate backbone with
nucleic acid bases
What do bacterias undergo?
bacteria that undergoes binary fission that will produce clones of itself
What do plasmids have?
Plasmids have inheritance without reproduction
How do plasmids come together?
Plasmids come together in a process called conjugation where their plasma membranes fuse which allows for extra copies to be
made. This way the cell can inherit DNA from another cell
Eukaryotes with asexual reproduction
- Unicellular eukaryotes likes euglena
- Reproduces by going through mitosis and cytokinesis and makes clones of itself
Hydra
multicellular eukaryote with asexual reproduction
How do hydra reproduce
- All the cells in its body grow by growing through the cell cycle 2. Under some conditions the cell can create its own individual which is a clone of the parent
Haploid eukaryote with sexual reproduction
- Reverse Mendelian
- Under some conditions the haploid cells can come together to form a zygote (gamete) which can then undergo meiosis and
produce more haploid cells
Mitochondria
- Have their own loop of DNA
- Have haploid genotypes
- Normally only inherit mitochondrial DNA from our mothers
DNA can also be described as
as a polymer of nucleotides, each with a sugar, phosphate, and nucleic acid base
4 bases found in all DNA
Thymine, adenine, cytosine and guanine
How is the information of DNA stored?
The information stored in DNA is stored in the sequence of these bases
What equals a nucleotide?
1 phosphate + 1 sugar + 1 base = nucleotide
What can nucleic acid bases form?
The nucleic acid bases may form hydrogen bonds with each other
The bases are very specific about what
which base they will form hydrogen bonds with
Adenine pairs with thymine
Cytosine pairs with guanine
Base pair
Two nucleic acids that are held together by hydrogen bonds are called base-pair
How is DNA typically found?
DNA is typically found double-stranded, with
complementary strands held together by base-pairs
- The sugar phosphate backbones tend to wrap around each other which
forms the characteristic double helix shape
What must happen to DNA for cell division?
DNA must be replicated for cell division
How does DNA replicate?
- Have to break hydrogen bonds and split the two parts of the DNA
- We then have to bring in nucleotides
that are complementary to the bases that are already there
o The two strands will both be used as templates
- The complementary nucleotides will
then bond with the templates and form 2 new strands
- The two DNA molecules will be identical to each other
What is DNA polymerase?
DNA polymerase is the enzyme that binds to the template strand and will bring in a nucleotide that is complementary to the base pair on the strand
shape of dna
The double stranded DNA is anti-parallel
What does the DNA polymerase impacts?
When the DNA polymerase unzips the strands, the ends will impact the direction of the DNA polymerase
What does the shape of DNA affect?
- Will affect the way molecules (like DNA polymerase) interact with the DNA strand
- The DNA polymerase will go in the opposite way for the two strands
How does DNA replicate in eukaryotic and prokaryotic cells?
- In prokaryotic cells we have a loop of DNA that replicates itself
- In eukaryotic cells, a replication bubble will form which is where the DNA polymerase will attach to start replicating the DNA
