STEP 2: ______ match up with complementary bases. Free nucleotides abundant in nucleus

In DNA there are two strands of nucleotides that wind together in a double helix - the strands run in ______ - the bases are are arranged in ______ - the base pairs are held together by _______

Strands are held together by ______ between specific pairs of bases

- Columbia University, NY -Investigated the composition of DNA -His findings by 1950 strongly suggested the base-pairings of A-T & G-C

In DNA, A, C, G, and T are linked by________ between deoxyribose and phosphate

First determined by Watson & Crick in 1953

Secondary Structure

occur when copying errors cause a change in the sequence of DNA nucleotide bases

In eukaryotic cells (animals, plants, fungi) DNA is stored in the nucleus, which is separated from the rest of the cell by a

A process where one strand of each daughter DNA comes from the parent DNA and one strand is new

[normally] exists as a single stranded polymer

1. Before a cell divides, the DNA strands unwind and separate 2. Each strand makes a new partner by adding the appropriate nucleotides 3. The result is that there are now two double-stranded DNA molecules in the nucleus. When the cell divides, each nucleus contains identical DNA

The paired strands are coiled into a spiral called

is described from 5' end, identifying the bases in order of occurrence, using the abbreviations A for adenosine, G for guanosine, C for cytidine, and T for thymine (or U for uracil in RNA) A typical sequence is written as

The model was developed by Watson and Crick in 1953.

Nucleotides are linked into 2 new strands of DNA by the enzyme, ________—_______ also proofreads for copying errors

DNA double strand is created by _______ between nucleotides

The primary structure of a nucleic acid is the ______

Met with Watson and Crick in _____ and shared his findings

The energy for the synthesis of the new strands comes from _______ of phosphate groups as the phosphodiester bonds form between the bases

Remember that for this (replication) to happen, DNA in the parent cell must be replicated (copied) before the cell divides – this process occurs during ______ in the cell cycle

Nucleic acid structure consists of

Cell division involving ______ produces 2 daughter cells that are genetically identical to each other and genetically identical to the parent cell

Shape and size is uniform for all life (i.e. DNA is identical)

The Okazaki fragments and ______ are joined by to give a single 3’-5’ DNA strand

_____ catalyzes the formation of 5’-3’ester bonds of the leading strand

open DNA section, called a

Between replications, the DNA is stored in a compact ball called ______, and is wrapped around proteins called ________ to form nucleosomes

Schematic representation of the strand separation in duplex DNA resulting from its

A ________ has a free 5’-phosphate group at one end and a free 3’-OH group at the other end The sequence is read from the free 5’-end using the letters of the bases This example reads 5’—A—C—G—T—3’

The pairing of the bases from the two strands is very specific. The complimentary base pairs are A-T and G-C Each pair consists of a purine and a pyrimidine, so they are the same width, keeping the two strands at equal distances from each other

The DNA is only organized into _______ during cell replication

The dna model looks like a twisted ladder – ______

The 3’-OH group of the sugar in one nucleotide forms an ______ to the phosphate group on the 5’-carbon of the sugar of the next nucleotide

are critical for binding proteins that regulate DNA function

The nucleotides in nucleic acids are joined by ______

The _______, which grows in the 3’-5’ direction, is synthesized in short sections called ______

Watson and Crick received a nobel prize in _____ for their work.

DNA replication involves several processes: 2. - the ______ then act as templates for synthesis of the new strands, which are complimentary in sequence

When a eukaryotic cell divides, the process is called _____ - the cell splits into two identical daughter cells - the DNA must be replicated so that each daughter cell has a copy

Properties of a DNA double helix

Nucleotides always bind to

STEP 1: Hydrogen bonds between base pairs are broken by the ________ and DNA molecule unzips. DNA molecule separates into complementary halves

DNA replication involves several processes: 3.- bases are added one at a time until two new DNA strands that exactly duplicate the _______ are produced

A = T & C = G

In 1953, _____ noted that DNA consists of two polynucleotide strands, running in opposite directions and coiled around each other in a double helix

DNA replication involves several processes: 1. - first, the DNA must be _____, separating the two strands

Without parallel base pairing this conformation could not exist

exists as a double stranded polymer

The strands of DNA are complementary because of

unwinds several sections of parent DNA