DNA Flashcards
Genome
Is the cells genetic information: mainly composed of DNA
Chromosomes
Are thread like structures within cells
- contains DNA and associated proteins
Gene
Is a segment of DNA that codes for a specific functional product; unit of genome
Transcription
Cells do not transfer the information coded in DNA directly but first make an RNA copy of the gene. This is called transcription
Central Dogma
The information is copied as RNA nucleotide sequences; RNA molecules in ribosomes then synthesize polypeptides in a process called translation.
These processes make up the CENTRAL DOGMA of genetics: DNA is transcribed to RNA, which is translated to form polypeptides.
DNA->RNA->protein
Nucleotides
Nucleus acids are polymers of basic building blocks called nucleotides.
Any of various compounds consisting of a nucleoside combined with a phosphate group and forming the basic constitution of DNA.
Deoxyribonucleotides
Are linked through their sugars and phosphates to form the two backbones of a helical, double stranded DNA(dsDNA) molecule.
Together make DNA?
Anti-parallel
The two strands are oriented in the opposite direction to each other; one strand runs in 3’ to 5’ direction,while the other runs in a 5’ to 3’ direction.
Scientists say the two strands are antipatallel.
The base pairs extend into the middle of the molecule in a way reminiscent of steps of a spiral staircase.
DNA replication
Is an anabolic polymerization process that allows a cell to pass copies of its genome to its decendants.
DNA begins
Helipads unzips the DNA molecule by breaking hydrogen bonds between complementary nucleotide bases, which exposes the bases of the replication fork.
Replication is semi- conservative
One strand serves as a template for the new strand
Each of the two new DNA molecules generated one of the original parental strand.
Two original strands are antipatallel, cells synthesize new strands in different ways.
One new strand, called the leading strand, is synthesized continuously-5’ to 3’- as a single long chain of nucleotides.
The other is called the lagging strand, is also synthesized 5’ to 3’ but in short segments that are later joined.
Helix stairs
A, G,T,C
A to G
T to C
- Primace
Comes in and lays the foundation for the replication process.
Complementary base pairs
The bases of nucleotides hydrogen bond to one another in specific ways called complementary base pairs. In DNA, the complementary bases thymine and Adenine bond together with two hydrogen bonds with Adenine.
