Nucleic Acids Flashcards
How many kinds of nucleic acid are there?
2
What are the two types of nucleic acid?
Deoxyribonucleic and ribonucleic acid
What does DNA stand for?
Deoxyribonucleic acid
What dies RNA stand for?
Ribonucleic acid
What are the four bases of DNA?
Guanine, cytosine, thymine, adenine
Which bases are complementary in DNA?
Cytosine and guanine, thymine and adenine
What makes up a nucleotide?
Sugar, phosphate, nitrogen contains base
What are the four bases of RNA?
Guanine, cytosine, adenine, uracil
Which are the complementary bases in RNA?
Guanine and cytosine, adenine and uracil
How does RNA differ from DNA?
It is an unpaired chain of nucleotides
What are the three forms of RNA?
Messenger, ribosomal, transfer RNA
What does mRNA stand for?
Messenger RNA
What does tRNA stand for?
Transfer RNA
What does rRNA stand for?
Ribosomal RNA
What does mRNA do?
Carries the genetic message to the ribosomes where the message is translated into a particular protein
What does tRNA do?
Molecule that carries amino acids to ribosomes where they are used to construct proteins
What does rRNA do?
Together with particular proteins makes the ribosomes found in the cytosol
What kind of sugar is in DNA?
Deoxyribose
What kind of sugar is in RNA?
Ribose
A sequence of DNA contains what percentage of adenine?
15%
A sequence of DNA contains what percentage of thymine?
15%
A sequence of DNA contains what percentage of cytosine?
35%
A sequence of DNA contains what percentage of guanine?
35%
What proportion of the molecule contains cytosine and guanine complementary pairs?
70%
The main difference between gene expression in eukaryotes and prokaryotes is that?
Eukaryotes splice out introns whereas prokaryotes don’t
Why is gene expression regulated?
- to conserve energy and cellular response
- genes are only switched on when required
What does Pre mRNA consist of?
Exons and introns
Which out of exons and introns are cut out as junk DNA?
Introns
How many bonds are there between cytosine and guanine?
3
How many binds are there between adenine and thymine?
2
What is the function of mRNA?
carry information from the nucleus to the ribosome
The function of transfer RNA in the cell is to?
carry specific amino acids to the ribosome
A DNA triplet codes for?
a specific amino acid to be inserted into a polypeptide
The first step of gene expression is?
Translation of DNA
The three dimensional shape of a protein can be seen in what structure?
Tertiary
How are proteins transported through the cell?
Endoplasmic recticulm
What are examples of a structural gene?
collagen, keratin, fingernails
What is an example of a transport protein?
haemoglobin, protein carrier
What is an example of a regulatory gene?
hormone, enzyme, major histocompatibility complex (MHC)
Is the synthesis of carbohydrates possible by the rough or smooth ER?
No
During translation mRNA is read in what direction by the ribosome?
5-3
What can alternative splicing explain?
How the expression of a single gene can lead to the production of different proteins
What does anti parallel mean when referring to DNA?
The strands are anti parallel as they have the same chemical structure but run in opposite directions. One runs 3 to 5 the other 5 to 3
What are three places DNA could be found in a plant cell?
Nucleus, chloroplasts, mitochondria
What happens during translation?
- dna unwinds and separates
- rna polymerase moves along and reads template strand
- complementary rna bases are added
- the final product is pre mRNA
What is the final product of translation?
Pre mRNA
What is the structure of a primary protein?
Sequence of amino acids
What is the structure of a secondary protein?
The coiled or pleated structure within the chain (alpha helix and beta pleated sheets)
What is the structure of a tertiary protein?
The overall 3D structure composed of secondary structures
What is the structure of a quaternary protein?
Two or more polypeptide chains joined together
What is gene regulation?
Genes are only transcribed and expressed when required which can save energy
Which bases are pyrimidines?
Cytosine, uracil and thymine (CUT)
Which bases are purines?
Guanine and adenine
How many rings are there in a purine base?
Two
How many rings are there in a pyrimidine base?
1
What is a nucleoside?
Only contains the sugar and base of a nucleotide not the phosphate
What binds to a silencer?
A repressor
What binds to an enhancer?
An activator
The enzyme needed to produce cDNA from an mRNA transcript is?
Reverse transcriptase
What does cDNA stand for?
Complementary DNA
