Nucleic Acids 3.1.5.1

Question 1

Name to nucleic acids

Answer 1

DNA, RNA

Question 2

What is the monomer of nucleic acid

Answer 2

Nucleotides

Question 3

What are nucleotides formed from

Answer 3

A pentose sugar, a nitrogen-containing organic base and a phosphate group

Question 4

How are nucleotides joined together

Answer 4

Condensation reactions occur to join the pentose sugar to the phosphate group and the nitrogenous base to form a nucleotide. Water is removed in the process

Question 5

What does each DNA nucleotide consist of

Answer 5

Consists of a deoxyribose pentose sugar, phosphate and one of the four different nitrogenous bases: Adelaide, cytosine, guanine and Thymine

Question 6

What makes adenine and guanine different from thymine and cytosine in DNA

Answer 6

Adenine and guanine are classified as purines (double ring structure) and thymine and cytosine are classified as pyrimidines (single ring structure).

Question 7

What part of the nucleotide forms the ‘backbone’ of DNA

Answer 7

Sugar and phosphate make up the backbones would you help together by hydrogen bonds between spits specific complimentary base pairs; which are A = T and C ≡ G

Question 8

How is a polynucleotide chain formed

Answer 8

Each polynucleotide chain is formed during a condensation reaction from nucleotides. Each nucleotide is joined together by phosphodiester bond between the phosphate group of one nucleotide, to the carbon (C3) group of another nucleotide.

Question 9

What is DNA composed of

Answer 9

DNA is composed of two antiparallel nucleotide chains wound around each other, held in place by hydrogen bonds to form a double helix

Question 10

Why can nucleic acid only be synthesised in the 5’ to 3’ direction

Answer 10

Because the enzyme DNA polyamory is that assembled nucleotide into DNA molecules can only attach nucleotide to the hydroxyl (OH) group on the 3’ carbon molecule.

Question 11

What is the structure of DNA in a eukaryote

Answer 11

• In eukaryotes, DNA is linear and associated with proteins called histones to form chromosomes
• Histones keep the package and order the DNA into structural units called nucleosomes. They are the chief protein components of chromatin, acting as spools around which DNA winds, and playing a role in the gene regulation.
• Organelles such as mitochondria and chloroplasts also have small strands of DNA within them

Question 12

What is the structure of DNA in a prokaryotes

Answer 12

• In prokaryotes, DNA molecules are smaller, circular and are not associated with proteins.
• They do not have chromosomes.
• Prokaryotes have additional DNA in the form of plasmids

Question 13

What is the function of DNA

Answer 13

• DNA is a stable information-carrying molecule. It’s sequence of bases determines the structure of proteins, including enzymes.
• Responsible for inheritance in most living organisms

Question 14

How is DNA adapted to enable it to carry out its function

Answer 14

• It is very stable and can passed from generation to generation without change.
• It is two separate strands and needs a joint only with hydrogen bonds, which allow them to separate during DNA replication.
• Eating in an extremely large molecule and therefore carries immense amount of genetic information.
• By having the specific base pairs within the helical cylinder of the deoxyribose-phosphate backbone, they genetic information is protected from being corrupted, to an extent, from outside chemical and physical forces.

Question 15

What does each RNA nucleotide consist of

Answer 15

It consist of the pentose sugar rivals, phosphate and one of four different nitrogenous bases: adenine, cytosine, guanine and uracil

Question 16

What is RNA composed of

Answer 16

A SINGLE polynucleotide strand

Not like DNA which has a double.

Question 17

How does RNA compare to DNA in terms of length

Answer 17

RNA is relatively shorter than DNA

Question 18

What is the main function of RNA

Answer 18

The main function of RNA is to carry information of amino acid sequence from the genes to where proteins are assembled and ribosomes in the cytoplasm

Question 19

What are the different types of RNA

Answer 19

There are 3 major types of RNA:
mRNA - messenger RNA
rRNA - ribosomal RNA
tRNA - transfer RNA 
these are found in both eukaryotes and prokaryotes

Question 20

What percentage of the total RNA in the cell is Ribosomal RNA (rRNA)

Answer 20

80%

Question 21

What percentage of the total RNA in the cell is Messenger RNA (mRNA)

Answer 21

3-5% depending on the protein synthesis activity at that time

Question 22

What percentage of the total RNA in the cell is Transfer RNA (tRNA)

Answer 22

15%

Question 23

What’s Ribosomal RNAs use

Answer 23

It is involved with the formation of ribosomes and is therefore important as the site of protein synthesis in a cell

Question 24

What is Messenger RNAs use

Answer 24

It is single stranded and forms in the nucleus, using one strand of DNA as its template. It is used to communicate the genetic code in the allele to the ribosome during protein synthesis.

Question 25

What is Transfer RNAs use

Answer 25

It is a single-stranded, clover leaf shaped molecule, held in place by hydrogen bonds. It is involved in carrying the amino acids through the cytoplasm to their correct places in a growing polypeptide chain.

Question 26

Similarities between DNA and RNA

Answer 26

Uses a, C, and G

Has sugar and a phosphate backbone

Question 27

Differences between RNA and DNA

Answer 27

• RNAs single-stranded whereas DNA is double stranded
• DNA is pentose sugar is deoxyribose whereas RNAs pentose sugar is ribose
• DNA structured into chromosomes
• RNA uses Uracil whereas DNA uses thymine
• DNA stores genetic information whereas RNA stores information about protein structure
• DNA is read by polymerises whereas RNA is read by ribosomes
• DNA can self replicate
• RNA can have multiple structures (mRNA, rRNA, tRNA)
• DNA can last for a long time whereas RNA does not usually last for a long time