Nucleotides and Nucleic acids

Question 1

What is a nucleotide made of?

Answer 1

-A pentose sugar- A nitrogenous base- A phosphate group

Question 2

What elements are nucleotides made up of?

Answer 2

-Carbon-Oxygen-Hydrogen-Nitrogen-Phosphate

Question 3

Why are nucleotides important?

Answer 3

-They’re the monomers that make up DNA and RNA

Question 4

What is DNA used for?

Answer 4

-To store genetic infomation, the instructions used to grow and develop.

Question 5

What is RNA used for?

Answer 5

-To make proteins from instructions in DNA

Question 6

What are ATP and ADP?

Answer 6

-Special types of nucleotides that are used to store and transport energy in cells

Question 7

What is ribose and what is it used in?

Answer 7

-A sugar that is used in RNA instead of deoxyribose

Question 8

What are the four phosphate groups in DNA?

Answer 8

-Adenine, Guanine, Cytosine, Thymine

Question 9

How do the phosphate groups in DNA pair?

Answer 9

• Adenine and Thymine

- Cytosine and Guanine

Question 10

What type of bases are adenine and guanine?

Answer 10

Purine

Question 11

What type of bases are cytosine and thymine?

Answer 11

Pyrimidine

Question 12

What pentose sugar is used in DNA?

Answer 12

Deoxyribose

Question 13

What does a purine base contain?

Answer 13

• Two carbon-nitrogen rings joined together

Question 14

What does a pyrimidine base contain?

Answer 14

• One carbon-nitrogen ring, making it a smaller base than purine

Question 15

What are the bases in RNA?

Answer 15

-Adenine, Uracil, Cytosine and Guanine

Question 16

What is a molecule of DNA made up of?

Answer 16

• Two polynucleotide chains

Question 17

What is a molecule of RNA made up of?

Answer 17

• A single polynucleotide chain

Question 18

How do you phosphorylate a nucleotide?

Answer 18

Add one or more phosphate groups to it

Question 19

What type of nucleotides are ATP and ADP?

Answer 19

Phosphorylated

Question 20

What does ADP contain?

Answer 20

-The base adenine, the sugar ribose, and two phosphate groups

Question 21

What does ATP contain?

Answer 21

-The base adenine, the sugar ribose and three phosphate groups

Question 22

How is ATP synthesised?

Answer 22

• From ADP and an inorganic phosphate group, using energy from an energy-releasing reaction e.g. the breakdown of glucose in respiration
• ATP is phosphorylated and a phosphate bond is formed

Question 23

What do nucleotides join together to form?

Answer 23

Polynucleotides

Question 24

How are polynucleotides formed?

Answer 24

• Nucleotides join up between the phosphate group of one nucleotide and the sugar of another
• A phosphodiester bond is formed

Question 25

What does a phosphodiester bond consist of?

Answer 25

-The phosphate group and two ester bonds

Question 26

What is the chain of sugars and phosphates known as?

Answer 26

The sugar phosphate backbone

Question 27

What do 2 polynucleotide strands join together to form?

Answer 27

A double helix

Question 28

What bonds joint the two polynucleotide strands together?

Answer 28

Hydrogen bonds between the bases

Question 29

Complementary base pairing

Answer 29

Each base only joining to it's specific partner

Question 30

How many hydrogen bonds form between A and T

Answer 30

2

Question 31

How many hydrogen bonds form between C and G

Answer 31

3

Question 32

How can DNA be purified?

Answer 32

Using a precipitate reaction

Question 33

When does DNA copy itself?

Answer 33

Before cell division

Question 34

Semi conservative replication

Answer 34

The copying of DNA so that half of the strands in each new DNA is made of original peices of DNA, new molecule contains half new DNA half old

Question 35

Why is DNA replication so accurate?

Answer 35

To ensure that genetic infomation is conserved each time the DNA in the cell is replicated

Question 36

Stage one of semi conservative replication

Answer 36

- DNA helicase breaks the hydrogen bonds between the two polynucleotide DNA strands - The helix unzips to form two single strands

Question 37

Stage two of semi conservative replication

Answer 37

- Each original single strand acts as a template for a new strand - Free-floating DNA nucleotides joint the exposed bases on each original strand by complementary base pairing

Question 38

Stage three of semi conservative replication

Answer 38

- The nucleotides of the new strands are joined together by DNA polymerase - This forms the sugar phosphate backbone - Hydrogen bonds form between the bases on the original and new strand - Strands twist to form a double helix