DNA structure and replication

DNA

Type of nitrogen base

Type of sugur used

Shape

A,T,C,G

deoxyribose

Double helix

RNA

type of nitrogen bases

Type of sugur used

Shape

A,U,C,G

Ribose

Single strand

Explain the base pairing rules of DNA and provide a example of DNA strand with its complementary strand

A always pairs with T

C always pairs with G

Example

ATGCCG

complentary strand is TACGGC

Draw the Structure of a nucleotide (make sure to label)

Sugur

Phosphate

Nitorgenous base

Tell the difference between purines and pyrimidines, including which nitrogen bases are which

Purines, larger bases with two rings

A and G are purines

Pyrimidines, smaller bases with one ring

C,T,U are pyrimidines

Explain in detail the structure of DNA molecule

Double helix, two strands of nucleotides twisted into a spiral

Backbone, sugur and phoshate

Bases, A,G,C,T

Anti parallel strand, the strands run in a opposite or anti parallel direction

Summerize the process of DNA replication, include the enzymes involved, and explain then importance of the process

Start, enzyme helicase unwinds the DNA double helix

Elongation

DNA polymerase, adds new nucleotides complementary to each original strand

Leading strand, synthesized continuously

Lagging stand, synthesized in short segments called okazai fragments

RNA primer, starts DNA synthesis

Termination, enzymes seal nicks resulting into identical DNA molecules

Importance, ensures genetic information is accurately copied for cell division

The difference between the leading strand and lagging strand

Leading strand, Synthesize continuously in the 5 to 3 direction toward the replicating fork

Lagging strand, synthesized discontinously in short segments the okazaki fragments away from the replication fork

Explain why DNA replication is considered to be semi conversative

Each new DNA molecule made consist of one original strand and one new strand, perserving half of the original molecule in each new copy

Be able to identify DNA and RNA

DNA, double stranded, contains T, deoxyribose sugur

RNA, single stranded, contains U, ribose sugur

What's a consequence for an error made during DNA replication

Malfuciton, genetic disorder, disease, mutations