Structure and replication of DNA Flashcards
What are proteins made of?
amino acids
State 3 functions of proteins.
- structural
- enzymes
- hormones
- antibodies
- receptors
Name the molecule that carries a copy of the DNA code from the nucleus to the ribosomes?
mRNA
What do we call a section of DNA that codes for a particular protein?
gene
In DNA, what does C stand for?
Cytosine
Where in a cell are proteins made?
ribosomes
What determines the protein that is made?
The order of the bases on the DNA
How many strands does DNA have?
2
In DNA, what does A stand for?
Adenine
In DNA, what does T stand for?
Thymine
Of the 3 things that make up a nucleotide, which is the one that can vary?
base (A,T,G,C)
In DNA, what does G stand for?
Guanine
State 5 things needed for DNA replication.
- DNA (template)
- primers
- 4 types of DNA nucleotide
- enzymes
- ATP
What is a gene?
section of DNA that codes for one protein
Which two chemicals make up the backbone of the DNA?
sugar and phosphate
Name the bond that holds the adjacent strands of DNA together at the bases.
hydrogen
What term is used to describe the fact that the 2 strands of DNA run in opposite directions?
antiparallel
Where in the cell does DNA replication take place?
nucleus
What solves the problem of DNA polymerase needing a pre-existing chain of DNA in order to add nucleotides?
A primer
Name the strand of DNA that can be formed continuously during DNA replication.
Leading strand
Name the enzyme that joins nucleotides to the new DNA strand during DNA replication.
DNA polymerase
Name the 3 things that make up a DNA nucleotide.
deoxyribose sugar, base, phosphate
Name the enzyme required to join the fragments on the lagging strand.
ligase
What name is given to the copying of DNA by means of PCR?
amplification
During PCR, why is the DNA heated to 92-98oC?
To separate the strands of DNA (break the hydrogen bonds)
During PCR, Why is it then cooled to between 50-65oC?
To allow primers to bind to target sequences
During PCR, why is it then heated again to between 70-80oC?
So heat tolerant DNA polymerase can replicate that section of DNA
What are some practical application of PCR?
solve crimes, paternity suits and diagnose genetic disorders
What is a primer?
A short strand of nucleotides
What is found at the 3’ end of the nucleotide?
Deoxyribose sugar
What is found at the 5’ end of the nucleotide?
Phosphate
In which direction can a new strand of DNA only be produced?
In a 5’ to 3’ direction
Which end of the template strand of DNA does a primer attach to?
3’ end
