12 Flashcards
(34 cards)
What are Genes made of?
DNA is the molecule of inheritance
Permanent genetic change in which the properties of one strain of dead cells are conferred on a different strain of living cells
Transformation
Each DNA building block is a ______ consisting of the ______, a phosphate
Nucleotide; pentose sugar deoxyribose
The nitrogen base is attached to the _____ of the sugar
1 Carbon
The phosphate is attached to the ______
5’ Carbon
What are the 4 Nitrogenous bases
Adenine,guanine, thymine, and cytosine
Nucleotides are linked by ______ bonds to form an alternating sugar-phosphate backbone
Covalent
The 3’ carbon of one sugar is bonded to the 5’ phosphate of the adjacent sugar to form a
3’ 5’ Phosphodiester Linkage
The 5’ end has a 5’ carbon attached to a phosphate and the 3’ end has a 3’ carbon attached to a
Hydroxyl Group
In a double stranded DNA molecule, the number of purines equals number of
Pyrimidines
A is complementary to
T
G is complementary to
C
DNA double helix has a constant width of
2 nm
A and T can be joined by
2 H bonds
G and C can be joined by
3 H bonds
DNA replicates with
Semiconservative
Two identical DNA double helices are produced, each consisting of one original strand from the parent molecule and one newly synthesized complementary strand
DNA replication
Both parent (old) strands might remain together, and the two newly synthesized strands would form a second double helix
Conservative replication
Parental and newly synthesized strands might become randomly mixed during the replication process
Dispersive Replication
Changed in the sequence of bases in DNA, which are reproduced in a new sequence of complementary bases during the next replication cycle
Mutations
Unwinds DNA
DNA helicase
Binds to single strands of DNA and prevents the helix from re-forming before it can be used as a template for replication.
Single-strand binding (SSB) Protein
Breaks one or both DNA strands, preventing excessive coiling during replication, and them in a more relaxed configuration. rejoin
Topoisomerase
Links nucleotide subunits to form a new DNA strand complementary to a DNA template
DNA Polymerase