2.4 - How is the CFTR protein made? Flashcards
Define mutation.
change in the genetic material in a cell.
What is a small change to an organism’s DNA called?
gene mutation
What can increase the chance of mutations?
environmental factors called mutagens
Define gene.
a sequence of nucleotides in DNA which code for a sequence of amino acids
What are the different forms of genes called?
alleles
What does each gene code for?
specific protein
How do alleles differ from each other?
in the sequences of their nucleotide
What is the result of difference in allele in the sequences of nucleotide?
makes a slightly diff. protein
Define genome.
- all DNA inside a cell
- genome contains full set of genes controlling growth & development of the organism of which the cell is a part
What is DNA biologically?
deoxyribose nucleic acid forms the genetic material of all living orgnsms.
What is DNA made up of?
2 polynucleotide chains forming a double helix.
each chain consist of a sugar-phosphate backbone
Define nucleotide.
made up of a pentose sugar
(ribose (RNA) or deoxyribose (DNA)), phosphate group & a nitrogenous base
How many hydrogen bonds are there between thymine and adenine base pairs?
2 hydrogen bonds
How many hydrogen bonds are there between cytosine and guanine base pairs?
3 hydrogen bonds
Describe how nucleotides join together to form DNA.
- condensation reaction takes place
- DNA polymerase catalyses reaction
- phosphodiester bond forms between 2 mononucleotides
DNA codes for what?
protein
How many bases code for one amino acid? What is this called?
3 - triplet codon
What 3 terms could you use to describe the genetic code?
- triplet (code)
- non-overlapping
- degenerate
Define non-overlapping.
each DNA triplet code is adjacent
Define degenerate.
there are more codons than there are aminos acids, becaue triplets can code for the same amino acid
Define transcription.
the process by which a DNA sequence is copied into an RNA sequence by the enzyme RNA
Define protein synthesis.
making of proteins
Define translation.
process by which genetic info stored in RNA is translated into a sequence of amino acids to form a protein
What is a codon?
3 mRNA bases that code for an amino acid
What is mRNA?
single stranded nucleic acid
What is RNA polymerase?
enzyme that causes the DNA strand to unwind in transcription
What is a template strand?
the DNA strand that mRNA attaches to in transcription
Why does Meselson & Stahl’s experiment mean that they accepted one model of DNA and not the other?
- generation 1 has a single band halfway btwn 15N & 14N
- because DNA has one strand containing 15N & one strand containing 14N
thus DNA replication is semi-conservative
