Chapter 20 Flashcards
Gene
A segment of DNA that codes for a protein
Double Helix
A twisted ladder or twisted ribbon
DNA
Deoxyribonucleic acid
DNA Replication
DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. Half the old DNA, half the new
DNA Helicase
DNA helicases are essential during DNA replication because they separate double-stranded DNA into single strands allowing each strand to be copied. They do this by breaking down the H-bonds between complementary base pairs
DNA ligase
Glues together the sugar-phosphate backbone and DNA fragments
DNA Polymerase 1 & 3
An enzyme that acts as a “proof-reader”
Steps of DNA separation
- DNA helicase unwinds the helix by breaking down the H-bonds between base pairs
- DNA Polymerase 3 links together the free nucleotides
- DNA Ligase glues together the sugar-phosphate backbone and DNA fragments
- DNA Polymerase 1&3 fill gaps that arise during replication, repair and recombination. “Proof-readers”
RNA
RNA carries genetic information that is translated by ribosomes into various proteins necessary for cellular processes
RNA vs. DNA
RNA contains ribose sugar instead of DNA’s deoxyribose sugar. RNA has Uracil instead of Thymine. RNA is single stranded, DNA is double stranded. DNA stays in the nucleus, RNA travels as a messenger
Protein Synthesis Steps
- Transcription (in nucleus)
- Translation (in cytoplasm)
Transcription
the process of making an RNA copy of a gene’s DNA sequence. This copy, called messenger RNA (mRNA), carries the gene’s protein information encoded in DNA.
Nucleotides
Replication Fork
a Y-shaped region where the parent DNA double helix splits into two strands, subsequently copied
Translation
Translation takes place on ribosomes in the cell cytoplasm, where mRNA is read and translated into the string of amino acid chains that make up the synthesized protein.
