DNA Flashcards
(26 cards)
What does DNA stand for
deoxyribonucleic acid
Where is DNA found
In the nucleus in chromosomes
What is the shape of DNA
A double helix
What is a gene
A small section of DNA found on a chromosome
What does each gene do
It comes for a particular sequence of amino acids which are put together to make a specific protein
How many amino acids are used
20
What is a genome
The entire set of genetic material in an organism
How does fully understanding the human genome help science and medicine
-it allows … to identify g… linked to different d…
-knowing what genes are linked to i… diseases help us to understand them better enabling us to develop e… treatments
-can trace the m… of certain p… of people
-it allows scientists to identify genes linked to different diseases
-knowing what genes are linked to inherited diseases help us to understand them better enabling us to develop effective treatments
-can trace the migration of certain populations of people
What are DNA strands
Polymers made up of lots of repeating units called nucleotides
What do nucleotide contain
-a sugar, a phosphate group and one base
What are the possible bases
-A
-T
-C
-G
Structure of nucleotides
-the s… and phosphate groups a…
-one of f… bases joins to each s…
-each base links to a base on the opposite s… in the h…
-A always pairs with …, and C always pairs with …
—>c… base pairing
-the sugar and phosphate groups alternate
-one of four bases joins to each sugar
-each base links to a base on the opposite strand in the helix
-A always pairs with T, and C always pairs with G
—>complimentary base pairing
What does the order of bases determine
The order of amino acids in a protein
What is each amino acid coded for by
a sequence of three bases
What do parts of the DNA do that don’t code for proteins
-they switch genes on and off
-to control whether or not a gene is expressed
Where are proteins made
In the cytoplasm on ribosomes
How are proteins made
-r… use the code in the …, which is found in the nucleus, but can’t move because it’s too …
-so the molecule … copies the code from the … and acts as a m…
-the correct … acids are brought to the r… in the correct order by carrier m…
-ribosomes use the code in the DNA, which is found in the nucleus, but can’t move because it’s too big
-so the molecule mRNA copies the code from the DNA and acts as a messenger
-the correct amino acids are brought to the ribosomes in the correct order by carrier molecules
Functions of proteins
E…- act as biological … to speed up c… reactions in the …
H…- used to carry m… around the body
S… p…- are physically …
Enzymes- act as biological catalysts to speed up chemical reactions in the body
Hormones- used to carry messages around the body
Structural proteins- are physically strong
What are mutations
When the sequence of DNA bases is changed
Can mutations be inherited
Yes
What happens when a gene mutates
-as the s… of DNA … codes for the sequence of amino … that make up the protein, m… can lead to changes in the p… that it codes for
-as the sequence of DNA bases codes for the sequence of amino acids that make up the protein mutations can lead to changes in the protein that it codes for
Effect of mutations
-most have little to … effect on the …
-some can s… affect the protein, like affecting the s… of the protein therefore affecting its ability to p… its f…
—>if the … site has change the … can no longer b… to it
—>structural … could lose their s…
-most have little to no effect on the protein
-some can seriously affect the protein, like affecting the shape of the protein therefore affecting its ability to perform its function
—>if the active site has change the substrate can no longer bind to it
—>structural proteins could lose their strength
What are the 3 different types of mutation
-insertions
-deletions
-substitutions
What happens in insertions
-where a new … is inserted into the … sequence where it shouldn’t be
-it changes the way g… of three … are read, therefore changing the … acid they c… for
-they have a …-on effect
-where a new base is inserted into the DNA sequence where it shouldn’t be
-it changes the way groups of three bases are read, therefore changing the amino acid they code for
-they have a knock-on effect
