Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
13 Cards in this Set
- Front
- Back
|
what are the monomers of a dna molecule and what bond joins them |
nucleotides, joined by phosphodiester bonds |
|
|
describe the three main components of a nucleotide |
• phosphate group • a deoxyribose sugar e.g ribose • nitrogen containing organic base |
|
|
state the four nucleotides which make up dna |
• adenine • thymine • cytosine • guanine |
|
|
state the two categories of the organic bases and which nucleotides are in which categorie |
• purines - guanine and adenine • pyrimidines - cytosine and thymine |
|
|
how many hydrogen bonds are require to join: 1.) adenine and thymine 2.) cytosine and guanine |
1.) two 2.) three |
|
|
what are the features of dna? |
- can carry instructions - stable - sugar phosphate backbone held in place with phosphodiester bonds - large/long - ability to be copied exactly - complimentary base pairing |
|
|
explain the semi-consevative replication model |
• dna helicase breaks the hydrogen bonds that hold the bases together
• free nucleotides bind to the exposed bases via hydrogen bonds
• nucleotides bound to the complimentary bases are joined together by dna polymerase, which forms phosphodiester bonds (between deoxyribose sugar and phosphate groups) and another sugar phosphate backbone, making the double helix |
|
|
describe the two main functions of dna |
- holds genetic information
- determines order of amino acids in a polypeptide |
|
|
describe properties of RNA |
- single stranded polynucleotide - contains uracil which replaces thymine - no complementary base pairs - short molecule -small molecule |
|
|
describe the role of mRNA |
- a complementary copy of dna - used to code for correct sequence of amino acids in a polypeptide -carries genetic code of dna to the ribosomes where a protein is made -had a base triplet called a codon |
|
|
describe the role of tRNA |
- located in cytoplasm - transfers the appropriate amino acids to the ribosome - folded into a clover shape via hydrogen bonds held together between specific base pairs - has a base triplet called an anti-codon and an amino acid binding site |
|
|
describe the role of rRNA |
- held together with other proteins forms the ribosome - directs translation of mRNA into a polypeptide |
|
|
define magnification and give the equation to calculate it |
= how many times larger the image is compared to the actual object |
