DNA Flashcards
What do DNA molecules and their associated proteins form?
Chromosomes
A strand of DNA is what?
A polymer of nucleotides
Which four types of nucleotides make up DNA?
Adenine, Thymine, Cytosine & Guanine
What is DNA formed out of?
Two nucleic acid strands (double helix)
How many sets of chromosomes does a human have?
23
What is the name of the process by which a cell copies its DNA?
Replication
Before DNA replication, a chromosome consists of what?
One double helix
What happens at the beginning of replication (unwinding)?
Enzymes break the hydrogen bonds that hold the double helix together, so the two
DNA strands unwind and separate
During the attachment, primers serve as what?
Attachment points for DNA polymerases
What occurs during the assembling?
DNA polymerase moves along a strand of DNA, it uses the sequence of bases as a template to assemble a new strand of DNA
from nucleotides
What occurs in the sealing?
The enzyme DNA ligase seals any gaps, so
the new DNA strands are continuous
What is a gene?
A DNA sequence that encodes an RNA or protein product
What is gene expression?
The process of transcription and translation; the multistep process in which information encoded in a gene guides the assembly of an RNA or protein product
What happens in transcription?
Enzymes use the gene’s DNA sequence to express themselves
What happens in transcription?
A strand of DNA acts as a template, a nucleotide can be added to a growing strand of RNA only if it is complementary, each nucleotide provides the energy of its own attachment to the end of a growing strand
