Nucleic Acids Flashcards
How do competitive inhibitors work?
The inhibitor has a similar shape to the substrate. Therefore it is complementary to the active site on the enzyme. This means that the substrate can’t bind to the active site to form enzymes substrate complexes.
Explain the effect of increasing substrate concentration on the rate of reaction without an inhibitor
More substrate into the active site meaning more enzyme substrate complex is are formed. This is because there are more chances of successful collisions. Low concentration means that not all active site are occupied. This achieves maximum rate
How is a DNA molecule replicated?
DNA replicates semiconservatively. This means that half of the DNA molecule is from the original and the other half is new. This starts with a DNA double helix strand being unwound and split into two single strands by the enzyme DNA helicase from carbon 3 to 5. One strand is the template. Free nucleotides in the nucleus from complimentary base pairs to the bases on the template strand. The enzyme in DNA polymerase moves along the template strand from carbon 3 to 5 but synthesises from carbon 5 to 3 and joins the bases together. Hydrogen bonds form between the complementary bases and phosphodiester bonds form between the bases and the strand.
Explain why DNA multiplication is semiconservative
Half of the DNA molecule is from the original and the other half is new. Original strand acts as a template
Why is complementary base pairing is important in DNA replication?
The new strand must be replicated without error by having the same sequence of nucleotides. This reduces mutations occurring and allows reformation of H bonds
