Nucleotides And Nucleic Acids Flashcards
1
Q
Nucleotides structure
A
- A pentose sugar (5 carbon atom)
- A phosphate group.
- A nitrogenous base.
Example of Nucleotide= ADP and ATP.
2
Q
Importance of Nucleotides
A
- They are monomers which make up DNA and RNA.
- DNA is needed for an org Siena to grow as it stores genetic information.
- RNA is used to make proteins.
3
Q
DNA nucleotides structure.
A
- Contains a pentose sugar called deoxyribose.
- They all have the same phosphate group.
- Each nucleotide can have 4 possible bases, adenine(A),Thymine (T),Cytosine(C), or guanine (G).
4
Q
RNA nucleotides.
A
- Ribose sugar, not deoxyribose.
- contains the same phosphate group.
- Has the same bases as DNA nucleotides (A,adenine.//C,cytosine//G,guanine). However, T,thymine is replaced with U,uracil.
5
Q
What are the two types of bases called in DNA and RNA nucleotides called?
A
- Purines.
- Pyrimidines.
6
Q
Which bases are Purines?
A
- Adenine and Guanine.
7
Q
Which bases are pyrimidines?
A
- Cytosine,Thymine, and Uracil.
8
Q
Difference between Purines and Pyrimidines
A
- A purine base contains 2 carbon-nitrogen rings joined together, whereas a pyrimidine base only has 1 carbon-nitrogen ring.
9
Q
How to phosphorylate a nucleotide
A
- Add one or more phosphate groups to it.
10
Q
ADP structure.
A
- Contains the base Adenine.
- Has two phosphate groups.
- contains a sugar ribose.
11
Q
ATP structure.
A
- Contains the base adenine.
- Contains the sugar ribose.
- Has three phosphate groups.
12
Q
What’s the structural difference between ATP and ADP
A
- ATP has 3 phosphate groups, whereas ADP has 2 phosphate groups.
13
Q
How is ATP synthesised?
A
- ADP is phosphorylated to form ATP and a phosphate bond if formed.
14
Q
How it ATP energy used?
A
- When energy is needed, ATP is broken back down into ADP.
- Energy is released from the phosphate bond and used by the cell.
15
Q
Polynucleotide structure
A
- Nucleotides join together to form polynucleotides.
- Nucleotides join up between the phosphate group of one nucleotide and the sugar of another.
- This forms a phosphodiester bond.
16
Q
DNA structure.
A
- Composed of two polynucleotide strands.
- Strand are joined together by hydrogen bonds.
- Forms a Double-helix shape.
- Each base can only pair with one particular partner (complementary base paring)… A-T(two hydrogen bonds formed). G-C (Three hydrogen bonds formed).
- Polynucleotide strands are antiparallel.
17
Q
How to purify DNA.
A
- Break up the cells in the sample.
- Make up a solution of detergent,salt and distilled water.
- Add the broken up cells to a beaker with the solution.
- incubate the beaker in water bath
- Put the beaker in an ice bath to cool the mixture down.
- Filter the mixture and transfer it to a clean boiling tube.
- Add protease enzymes to the filtered mixture.
- Dribble down some cold ethanol down the side of the tube to form a layer on top of the mixture.
- The DNA will then form a white precipitate after a few minutes.
18
Q
Why does DNA replicate?
A
- Means each new cell has the full amount of DNA.
- Important for making new cells.
- Important for passing genetic information from generation to generation.
19
Q
How is DNA replicated?
A
- DNA helicase breaks the hydrogen bonds between the two polynucleotide DNA strands.
- The helix unzips to form two single strands.
- The original strand acts as a template for a new strand.
- Free-floating nucleotides join to the exposed bases on the template strand by complementary base pairing.
- The bases are joined together by DNA polymerase.
- Hydrogen bonds form between the bases.
- The new strands twist to form a double helix.
20
Q
Why is DNA replication so important?
A
- It is very accurate and it is important for the conservation of energy.
21
Q
What is a gene?
A
- A sequence of DNA nucleotides that codes for a polypeptide.
22
Q
mRNA function
A
- Carried the genetic code from the DNA in the nucleus to the cytoplasm.
23
Q
tRNA structure
A
- Single polynucleotide strand which is folded into a clover shape.
- hydrogen bonds between specific base pairs hold the molecule in shape.
- Has a specific sequence of three bases at one end (anticodon).
- Have an amino acid binding site at the other end.
24
Q
tRNA function
A
- Carries the amino acids that are used to make proteins to the ribosomes.
25
Q
rRNA function
A
- Helps to catalyse the formation of peptide bonds between the Amino acids.
26
Q
What are the 3 features of genetic coding?
A
- The code is non-overlapping.
- The code is degenerate.
- The code is universal.
27
Q
What does non-overlapping mean?
A
- The base triples do not share their bases.
28
Q
What does degenerate mean?
A
- There are more possible combinations of triplets than amino acids.
- This means that some amino acids are coded for by more than 1 base.
29
Q
What does universal mean?
A
- The same specific base triplets code for the same amino acid in all living things.
30
Q
Where does transcription occur?
A
- In the nucleus
31
Q
Where does translation occur?
A
- In the cytoplasm.
32
Q
Transcription process
A
- DNA copied into mRNA.
Free RNA nucleotides line up //by complementary base paring//to the template strand of DNA//This is catalysed by RNA polymerase.
33
Q
Translation process
A
- mRNA moves to the ribosomes.
- tRNA molecule binds to mRNA.
- Anticodons pair with codons.
- Specific amino acids attached to tRNA.
- formation of peptide bond between amino acids.
