1.1 Biological Molecules: DNA

Question 1

What is DNA? What is it made up of?

Answer 1

DNA stands for deoxyribose nucleic acid.

It is made up of many nucleotides.

it is made up of 4 nitrogenous bases Adenine, Guanine, Cytosine, and thymine.

The DNA polymer is a double helix

Question 2

What is a nucleotide? What is it made up of?

Answer 2

the monomer that makes up DNA. it is made up of Deoxyribose (pentose sugar), a nitrogenous base and one phosphate group.

4 nitrogenous bases Adenine, Guanine, Cytosine, and thymine.

Question 3

What is a polynucleotide and how is it made?

Answer 3

A polynucleotide is a polymer of these nucleotides.

It is created by a condensation reaction between the deoxyribose sugar and the phosphate group creating a phosphodiester bond. Which are strong covalent bonds and therefore help to make sure the genetic code is not broken down.

Question 4

how does the structure of DNA relate to its function?

Answer 4

Stable structure

Double-stranded so replication can occur using one template strand

Weak hydrogen bonds making it easy to unzip strands

Large molecule to carry lots of information

Complementary base pairing allows identical copies to be made

Question 5

What is RNA? What is it made up of?

Answer 5

RNA is a polymer formed from nucleotides of Ribose, a Nitrogenous base and a phosphate group.

RNA has the base uracil instead of thymine . In comparison to the DNA polymer, the RNA p[polymer is a relatively short polynucleotide chain and is single-stranded.

Question 6

What is the function of RNA?

Answer 6

The function of RNA is to copy and transfer the genetic code from DNA in the nucleus to the ribosomes. Some RNA is also combined with proteins to create ribosomes.

Question 7

Name all the types of RNA.

Answer 7

mRNA
tRNA
rRNA

Question 8

What is the function of mRNA?

Answer 8

mRNA is a copy of a gene from DNA.

It is made in the nucleus and then it leaves the nucleus to copy the genetic code of one of the genes to a ribosome in the cytoplasm.

Question 9

What is the function of tRNA?

Answer 9

tRNA is transfer RNA is found only in the cytoplasm it is single-stranded but folded to create

Question 10

rRNA what is it and what is its function?

Answer 10

ribosomal RNA is the type of the RNA that makes up the bulk of ribosomes.

Question 11

Differences between the DNA and RNA monomers?

Answer 11

DNA contains the base thymine whereas RNA contains uracil instead.

DNA contains the pentose sugar deoxyribose, whereas RNA contains the pentose sugar ribose.

DNA is much larger

DNA is double-stranded

Question 12

DNA replication process?

Answer 12

Semi-conservative repication

Question 13

Step one of semi-conservative replication.

Answer 13

DNA helicase breaks the hydrogen bonds between the complementary base pairs between the two strands within a double helix. This causes the DNA double helix to unwind.

Question 14

Step two of semi-conservative replication.

Answer 14

Each of the separated parental DNA strands acts as a template.
free floating DNA nucleotides within the nucleus are attracted to their complementary base pairs on the template strands of the parental DNA.

Question 15

Step three of semi-conservative replication.

Answer 15

The adjacent nucleotides are joined together to from a phosphodiester bond by a condensation reaction.

DNA polymerase catalyses the joining together of the adjacent nucleotides.

Question 16

Step four of semi-conservative replication.

Answer 16

the two sets of daughter DNA contain one strand of parental DNA and one newly synthesised strand.

Question 17

Name the two DNA enzymes and their function.

Answer 17

DNA helicase unzips genes

DNA polymerase creates phosphodiester bonds between the free-floating nucleotides

Question 18

Who discovered the structure of DNA?

Answer 18

Watson and crick

Question 19

What did Meselson and Stahl find out?

Answer 19

that DNA replicates via semi-conservative replication.