• Created by: Davina1st
  • Created on: 17-11-20 19:04
What are the two types of nucleic acid?
1 of 37
What elements do nucleic acids contain?
Carbon, hydrogen, oxygen, nitrogen and phosphorus
2 of 37
What are the nucleotides three components?
A pentose monosaccharide (DNA/RNA), a phosphate group po42- and a nitrogenous base
3 of 37
How are nucleotides linked together?
By condensation reactions, to form a polymer, a polynucleotide.
4 of 37
What is a phosphodiester bond and how does it form?
The fifth carbon on the pentose sugar (5') forms a covalent bond with the third carbon (3') on an adjacent nucleotide. This forms a long sugar phosphate backbone.
5 of 37
How are phosphodiester bonds broken?
A hydrolysis reaction
6 of 37
What does DNA stand for?
Deoxyribonucleic acid
7 of 37
How many different bases are there in DNA?
8 of 37
What are the four bases in DNA?
Adenine, cytosine, thymine and guanine
9 of 37
What is a pyrimidine/ which bases?
The smaller bases which have a single carbon ring structure - Thymine and cytosine
10 of 37
What is a purine/ which bases?
The larger bases, with a double ring structure - Adenine and Guanine
11 of 37
What bases are complimentary and go together?
A-T and C-G
12 of 37
How many strands are there of DNA, What shape does this make it?
2 strands which forma double helix, held together by hydrogen bonds. The two strands are antiparallel.
13 of 37
What does RNA stand for?
Ribonucleic acid
14 of 37
How are RNA nucleotides different to DNA nucleotides?
RNA has a ribose sugar instead of a deoxyribose, it is only composed of one strand so cannot form a double helix. It also replaces the base Thymine with Uracil.
15 of 37
RNA nucleotides form polymers the same way as DNA, True or False?
True, phosphodiester bonds by condensation reactions.
16 of 37
How many hydrogen bonds are in-between each base?
A-T(U)= 2 H bonds C-G= 3 H bonds
17 of 37
Describe how you would extract DNA from a strawberry, give reasons for each stage
Grind up the strawberry (breaks cell walls), MIx with detergent (breaks down cell membrane), add protease enzyme (break down proteins in cell) add ethanol slowly as a layer on top (causes DNA to form precipitate). DNA can then be picked up
18 of 37
What type of replication is DNA replication?
Semi conservative
19 of 37
What experiment is proof for semi conservative replication?
Meselson and Stahl
20 of 37
What does semi conservative replication mean?
Two new molecules of DNA are produced, each one consists of one old strand of DNA and one new strand.
21 of 37
What is the role of DNA helicase in DNA replication?
Unwinding and separation of the two strands of DNA double helix is carried out by enzyme DNA helicase. Travels along DNA backbone catalysing reactions that break the H bonds between base pairs as it reaches them.
22 of 37
What is the role of DNA polymerase in DNA replication?
Catalyses the formation of phosphodiester bonds between free nucleotides and the exposed base.
23 of 37
Describe continuous replication and the leading strand
DNA polyermase moves in one direction from 3' to 5'. As DNA only unwinds in one direction, DNA polymerase has to replicate the strands in opposite directions. The strand unzipped from 3' end in leading strand, replicated continously.
24 of 37
Describe discontinuous replication and the lagging strand
The other strand, unzipped from 5' end, so DNA polymerase has to wait for a section of the strand to unzip to work back along the strand. This results in DNA being produced in segments called Okazaki fragments, which then have to join.
25 of 37
What is a mutation?
When there is a fault in the pairing of bases during DNA replication. They occur randomly and spontaneously.
26 of 37
What is a gene?
A section of DNA that contains the complete sequence of bases to code for a protein.
27 of 37
What is the genetic code?
The idea that DNA must code for a sequence of amino acids which in turn make tertiary and quaternary struct proteins.
28 of 37
What is a triplet code?
Codon, Sequence of three bases, each codon codes for an amino acid.
29 of 37
What does a degenerate code mean?
More than one codon can code for the same amino acid, but codons never overlap.
30 of 37
Why does transcription in protein synthesis take place?
DNA is too large to leave the nucleus and travel to a ribosome where translation takes place, so the base sequence of genes is copied to create mRNA which
31 of 37
Describe the process of transcription
Antisense strand, running 3' to 5' acts as a template strand, so the complimentary RNA strand formed carries the same base sequence as the sense strand. Free RNA nucleotides pair with DNA, phosphodiester bonds formed. = mRNA.
32 of 37
Describe the process of translation
mRNA binds to small subunit of ribosome at start codon AUG, tRNA with complimentary anticodon (UAC) bind to mRNA. Another tRNA with anticodon UGC binds to next codon on mRNA. First aa is transferred to the second by peptide bond. Ribosome moves along
33 of 37
What do cells require energy for?
Synthesis, transport and movement.
34 of 37
What does ATP stand for and what is its structure like?
Adenosine triphosphate, 3 phosphate groups a pentose sugar (ribose) and a nitrogenous base (always adenine)
35 of 37
How does ATP release energy?
Hydrolysis reaction, one phosphate group is broken off by water. This creates adenosine diphosphate (ADP)
36 of 37
What are some properties of ATP?
Small, water soluble, releases energy in small quantities, easily regenerated, contains bonds between phosphates with immediate energy
37 of 37

Other cards in this set

Card 2


What elements do nucleic acids contain?


Carbon, hydrogen, oxygen, nitrogen and phosphorus

Card 3


What are the nucleotides three components?


Preview of the front of card 3

Card 4


How are nucleotides linked together?


Preview of the front of card 4

Card 5


What is a phosphodiester bond and how does it form?


Preview of the front of card 5
View more cards


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all DNA, genetics and evolution resources »