Nucleotides And Nucleic Acids

Question 1

Nucleotides structure

Answer 1

• A pentose sugar (5 carbon atom)
• A phosphate group.
• A nitrogenous base.
  Example of Nucleotide= ADP and ATP.

Question 2

Importance of Nucleotides

Answer 2

• 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.

Question 3

DNA nucleotides structure.

Answer 3

• 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).

Question 4

RNA nucleotides.

Answer 4

• 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.

Question 5

What are the two types of bases called in DNA and RNA nucleotides called?

Answer 5

• Purines.

- Pyrimidines.

Question 6

Which bases are Purines?

Answer 6

• Adenine and Guanine.

Question 7

Which bases are pyrimidines?

Answer 7

• Cytosine,Thymine, and Uracil.

Question 8

Difference between Purines and Pyrimidines

Answer 8

• A purine base contains 2 carbon-nitrogen rings joined together, whereas a pyrimidine base only has 1 carbon-nitrogen ring.

Question 9

How to phosphorylate a nucleotide

Answer 9

• Add one or more phosphate groups to it.

Question 10

ADP structure.

Answer 10

• Contains the base Adenine.
• Has two phosphate groups.
• contains a sugar ribose.

Question 11

ATP structure.

Answer 11

• Contains the base adenine.
• Contains the sugar ribose.
• Has three phosphate groups.

Question 12

What’s the structural difference between ATP and ADP

Answer 12

• ATP has 3 phosphate groups, whereas ADP has 2 phosphate groups.

Question 13

How is ATP synthesised?

Answer 13

• ADP is phosphorylated to form ATP and a phosphate bond if formed.

Question 14

How it ATP energy used?

Answer 14

• When energy is needed, ATP is broken back down into ADP.

- Energy is released from the phosphate bond and used by the cell.

Question 15

Polynucleotide structure

Answer 15

• 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.

Question 16

DNA structure.

Answer 16

• 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.

Question 17

How to purify DNA.

Answer 17

• 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.

Question 18

Why does DNA replicate?

Answer 18

• Means each new cell has the full amount of DNA.
• Important for making new cells.
• Important for passing genetic information from generation to generation.

Question 19

How is DNA replicated?

Answer 19

• 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.

Question 20

Why is DNA replication so important?

Answer 20

• It is very accurate and it is important for the conservation of energy.

Question 21

What is a gene?

Answer 21

• A sequence of DNA nucleotides that codes for a polypeptide.

Question 22

mRNA function

Answer 22

• Carried the genetic code from the DNA in the nucleus to the cytoplasm.

Question 23

tRNA structure

Answer 23

• 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.

Question 24

tRNA function

Answer 24

• Carries the amino acids that are used to make proteins to the ribosomes.

Question 25

rRNA function

Answer 25

• Helps to catalyse the formation of peptide bonds between the Amino acids.

Question 26

What are the 3 features of genetic coding?

Answer 26

• The code is non-overlapping.
• The code is degenerate.
• The code is universal.

Question 27

What does non-overlapping mean?

Answer 27

• The base triples do not share their bases.

Question 28

What does degenerate mean?

Answer 28

• There are more possible combinations of triplets than amino acids.
• This means that some amino acids are coded for by more than 1 base.

Question 29

What does universal mean?

Answer 29

• The same specific base triplets code for the same amino acid in all living things.

Question 30

Where does transcription occur?

Answer 30

• In the nucleus

Question 31

Where does translation occur?

Answer 31

• In the cytoplasm.

Question 32

Transcription process

Answer 32

• 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.

Question 33

Translation process

Answer 33

• 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.