DNA Replication

Complementary pair of Cytosine

Guanine

Complementary pair of Adenine

Thymine

Very weak bonds

Hydrogen bonds, which hold complementary base pairs together in DNA structure.

Double Helix

Twisted, double-stranded structure of a DNA molecule. Sugar and phosphate make the backbone

Gene

The segment of DNA that codes for specific traits.

Nucleotide

building block for DNA - consisting of a sugar, a phosphate group, and a nitrogenous base.

Chromosome

structure made of coiled DNA.

Leading Strand

The strand of DNA that is synthesized continuously toward the replication fork

Lagging Strand

The strand of DNA that is synthesized discontinuously in short fragments called Okazaki fragments away from the fork, built in the 5' to 3' direction.

What direction the DNA polymerase read the template

3' to 5'

Why is lagging strands made in fragments

Its template runs opposite the fork’s movement

Okazaki Fragments

Short pieces of new DNA made on the lagging strand

Lagging template runs

3’ to 5’

Leading template runs

5’ to 3’

What is the main difference between the strands?

Leading is continous; lagging is made in fragments

Polymerase direction

5’ to 3’

Helicase

Unwinds and unzips the DNA double helix during replication.

Primase

puts primer down for DNA polymerase

Polymerase

build new complementary nucleotides

ligase

combines frames together

Purines

Nitrogen bases with 2 rings, adenine and guanine

Pyrimidines

Nitrogen bases with 1 ring, cytosine, thymine, and uracil

DNA vs. RNA

DNA has 2 strands, deoxyribose sugar, and thymine. RNA usually has 1 strand, ribose sugar, and uracil.

What are the functions of DNA and RNA?

DNA stores genetic instructions. RNA helps use those instructions to make proteins.

G1

Cell grows, carries out normal functions, and makes proteins and organelles.

S phase

DNA is replicated

G2

cell growth and preparing for cell division (mitosis),repairs damaged DNA

Mitosis

Prophase, Metaphase, Anaphase, Telophase. The duplicated chromosomes separate into two identical sets of chromosomes.

Interphase

G1, S, G2

Prophase

Chromatin condenses into chromosomes, nuclear membrane breaks down, spindle fibers are produced.

Metaphase

Lined up in middle - spindle fibers attach to the centromere of each pair of sister chromatids

Anaphase

Chromatids pull apart

Telophase

2 new nuclei form, cell begins to split

Cytokinesis

Where the cytoplasm divides and forms two new Genetically Identical cells.

Centromere

Holds sister chromatids together and helps them separate during cell division.