Download • Double helix -- twisted ladder shape of DNA, like spiral staircase

January 28, 2015
Study guide for quiz on DNA
Vocabulary to know:
• DNA -- Deoxyribonucleic acid, makes up genes (& chromosomes)
• RNA -- Ribonucleic acid, messenger RNA takes a message to the
ribosome for translation into a protein
• Ribosome -- organelle in cytoplasm that makes protein (translates mRNA
into string of amino acids)
• Replicate -- make exact copy of DNA, DNA strands split apart and each
one has 2nd strand filled in with matching nucleotides
• Gene expression -- going from DNA to RNA to protein which results in
phenotype, how the genotype determines the phenotype
• Template -- model/pattern/stencil that makes copying easy and exact
• Nucleotide -- basic unit of DNA, phosphate + sugar + nitrogen base
• Transcription -- making mRNA from DNA, determined by pattern in
DNA, happens in nucleus
• Translation -- ribosome reading code of mRNA and making protein that
goes with that code
• Double helix -- twisted ladder shape of DNA, like spiral
staircase
• Complementary base pairing -- A only goes with T (or U in
RNA), G only goes with C, fit like lock and key
• Chromosome -- very long molecule of DNA with millions
of nucleotides, contains our genes, we have 46
January 28, 2015
1.
What are the 3 parts of a nucleotide? (Be able to label them.) sugar,
phosphate, nitrogen base
2.
What makes up the backbone of the DNA double helix? sugar,
phosphate
3.
What makes up the “rungs” of the DNA “ladder”? nitrogen bases
4.
What letters represent the 4 nitrogen bases in DNA? A, G, T, C
5.
Which letters bind with which? A - T, G - C
6.
What kind of bond holds the nitrogen bases together in the ladder
“rung”? hydrogen Why is this a good bond for this location? allows
DNA to unzip easily
7.
What are the 3 functions of DNA?
* Passing on genes to daughter cells so body can make more cells for
growth and maintenance, new cells will have genes identical to original
cells so body stays same throughout
* pass on genetic information to offspring so species continues to next
generation
* gene expression -- codes for proteins that are important for life (growth,
repair, function), produces phenotype
8. Why does every new cell in your body need a copy of your DNA? so
it can make correct proteins for its function (pancreas cells make
insulin, etc.)
9. How might DNA technology affect you? DNA fingerprinting,
identifying genetic disease or best treatment for diseases, genetically
modified food
January 28, 2015
10. How does DNA store the code for proteins?
in the order of its bases (A, G, C, T), each triplet of letters
codes for one amino acid
11. How does DNA replication work?
DNA unzips into 2 complementary strands, then each
strand is filled in with the matching bases, produces 2
exact copies of DNA
12. Why is the replication almost foolproof? only 1 base
(letter) can fit in each spot, A only goes with T and G only
goes with C
13. How does DNA determine phenotype? It codes for the
proteins that produce the phenotype.
14. Where does transcription happen? nucleus
15. Where does translation happen? ribosome/cytoplasm
16. Given half of a DNA strand, be able to fill in the other half and show the
mRNA that would be made.
DNA
RNA
AA T C G A T C A
AA T C G A T C A
T T A G C T A G T
U U A G C U A G U
Know that a protein is made up of amino acids.
genotype -->
DNA
-->
protein --> phenotype
RNA
--> protein
transcription
translation
nucleus
ribosome/cytoplasm