Structure of DNA Flashcards
What is a virus?
A virus is simply DNA trapped in a protein capsule.
What is a bacteriophage?
A bacteriophage is a virus
that attacks/infects bacteria.
Viruses highjack a living cell’s ability to transcribe and translate in order to make many copies of itself, this causes cells to?
causing the cell to lyse and release
Why are viruses not living things?
They lack the machinery of life as they can not reproduce on their own.
The monomer of DNA is a
nucleotide.
A nucleotide consists of
Phosphate group
Deoxyribose (a sugar)
Nitogenous base
The phosphate group is attached to
the _’ carbon.
A hydroxyl group (-OH) is attached
to the _’ carbon.
5,3
Nucleotides join together by what reaction
Condensation or dehydration synthesis.
There are ___ strands of DNA in a
DNA molecule.
two
The sides of the molecule consist of alternating sugar and phosphate, which is called..
sugar backbone
The center of the molecule contains the
nitrogenous bases.
Purine is two ring, which contains..
Adenine(A) and Guanine (G)
Pyrimidines are one rings, and contains
Thymine (T) and Cytosine ( C ) and uracil
Adenine + Thymine, how many hydrogen bonds?
2
Guanine + Cyotosine, how many hydrogen bonds?
3
What is Anti-parallel?
The sugar phosphate backbones of DNA run in opposite
directions
One side runs 5’ to 3’
The other side runs 3’ to 5’
Each DNA molecule makes up a
chromosome
What is a chromosome
A strand of DNA
Each cell in our body contains __ pairs of chromosomes = __ in total.
23, 46
Each chromosome contains many
genes
What is a gene
A sequence of nitrogenous bases which code for a trait.
A DNA molecule contains many genes.
Each gene has a _________ _________ of bases.
unique sequence
What is Prokaryotic?
organism that lacks a nucleus, and membrane bound organelles and is always single celled (all bacteria, some protists (algae), some fungi (yeast))
What is eukaryotic?
organism that has a nucleus and is usually multicellular, has membrane organelles (protists, fungi, plants, animals)
Prokaryotic organisms do not have a nucleus, therefore the DNA is kept in a separate area of the cell called the
Nucleoid
Prokaryotic DNA is ______ stranded and __________.
double, circular
Prokaryotic DNA must be compacted ______ times to fit into a prokaryotic cell.
1000
Plasmids use the bacterial cell’s machinery for ________ and can be used to transform nearby _____.
replication, cells
How can plasmids be integrated into a bacteria’s genome
chromosomal DNA
What are episomes
Integrated form of plasmid with DNA
How does the DNA get compacted so much?
Specialized proteins help fold the DNA into loop like structures. This
compacts the DNA 10 times.
After the folding, additional compaction is completed by a process called
supercoiling. What is supercoiling?
.
Supercoiling is simply twisting the DNA.
Most of prokaryotic DNA codes
for either a protein or a…..
regulatory sequence
What is Regulatory Sequence?
are genes
that control the turning on or
off of other genes according to our needs.
Eukaryotes have much more ____
(genome is larger) than Prokaryotes.
DNA
DNA is located in the ______ of the cell and never leaves.
nucleus
DNA is in linear chromosomes, ____________ also has its own DNA
mitochondria
Therefore compaction in ____________ is much more
complicated than _______________
Eukaryotes, prokaryotes
Eukaryotic DNA compaction is accomplished by using a ________ __ __________.
series of proteins.
Nucleosomes are connected by ..
LINKER DNA
Organisms that have similar structures share more of the
same _____ that organisms that differ greatly.
genes
Most Eukaryotes are _______ (have two copies of each
gene), some are _______ (ferns, algae), and some are
______ (specially bred)
diploid, haploid, triploid
Completely uncompacted DNA is
called __________ in Eukaryotes
Chromatin
The hereditary molecule must meet what following criteria?
1) Had to contain information to make enzymes and other proteins
2) Had to have the ability to duplicate itself without many errors
3) Had to have the flexibility to permit a few random mutations to increase variation within a population
What is prokaryotic DNA
- double stranded
- Circular and small
- Has a single origin for DNA replication
-Located in the cytoplasm (nucleoid)
What is eukaryotic DNA?
-Linear and larger
-Double stranded
-Located in the nucleus
-Has multiple origins for DNA replication
Similarities between prokaryotic DNA and eukaryotic DNA?
-Both double stranded
-Both use the same genetic code (A,T,C,G)
