DNA -Genetics

Replication

The process by which DNA is copied during the cell cycle

DNA Polymerase

Enzymes that bond the new nucleotides together in replication

Main parts of DNA

Phosphate group, deoxyribose sugar, nucleotides, and hydrogen bonds

Phosphate group

Helps support the DNA structure

Deoxyribose sugar

Helps support the DNA structure

Nucleotides

monomers of nucleic acids

Hydrogen bonds

Holds nucleotides together

Leading Strand

Is replicated continuously in 5'-3'

Lagging Strand

Harder to replicate, takes more time, and replicates in segments of 5'-3', creates Okazaki Fragments.

Replication Fork

Where enzymes unzip the double helix

Okazaki Fragments

Fragments of DNA lagging strand in replication from 5' to 3' (the DNA polymerase goes backwards)

Why DNA replication is called semiconservative?

Because one old strand is conserved, and one complementary new strand is made.

DNA Helicase

Unzips the double helix to separate the strands of DNA

Adenine

pairs with Thymine

Guanine

pairs with Cytosine

Histone

protein molecule around which DNA is tightly coiled in chromatin

nucleosomes

Bead-like structures formed by histones and DNA

Centromere

Area where the chromatids of a chromosome are attached

p arm

short arm of chromosome

q arm

long arm of chromosome

telocentric

centromere at end

submetacentric

centromere slightly off center

metacentric

centromere in middle

Fluorescence in situ hybridization (FISH)

Technique used to detect a given nucleotide sequence within intact cells on a microscope slide

Jacob's Syndrome (XYY)

tall, persistent acne, speech and reading problems

Klinefelter Syndrome

A chromosomal disorder in which males have an extra X chromosome, making them XXY instead of XY.

Down's Syndrome

A congenital disorder caused by having an extra Chromosome 21.

Edwards syndrome

Trisomy 18 associated with rocker-bottom feet, low-set ears, heart disease

Turner Syndrome

A chromosomal disorder in females in which either an X chromosome is missing, making the person XO instead of XX, or part of one X chromosome is deleted.

Patau Syndrome

trisomy 13 (Puberty @ age 13) → cleft palate, microphthalmia, polydactyly, rocker-bottom feet (most severe trisomy)

gene

A segment of DNA on a chromosome that codes for a specific trait

Amino Acids

monomers of proteins

Polypeptide

A polymer (chain) of many amino acids linked together by peptide bonds.

Transcription

the organic process whereby the DNA sequence in a gene is copied into mRNA

Translation

the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm

Functional mRNA

Processed mRNA ready for translation. "Messenger RNA"

Splicing

the process of removing introns and reconnecting exons in a pre-mRNA

Capping

The process of linking a 7-methylguanosine residue to the 5' end of RNA. The 5' cap protects the mRNA from degradation and is required for translation in the cytoplasm.

Tailing

a poly A tail is added to the most mature mRNAs at the 3' end. This is the final step before the mRNA leaves the nucleus to complete translation

Ribosome

Cytoplasmic organelles at which proteins are synthesized.

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

post-translation modification

Chemical changes to proteins after synthesis that prepare it for its final use in the cell.