2 Nucleic Acids

Question 1

Draw the structure of a nucleotide, what are the components in it?

Answer 1

Phosphate, pentose sugar, organic base

Question 2

What is the difference between RNA and DNA?

Answer 2

DNA- without the oxygen (sugar is deoxyribose
RNA- with oxygen (ribose sugar)

Question 3

What are the bases called?

Answer 3

DNA - Adenine, thymine, Guanine and Cytosine
RNA- Adenine, Uracil, Guanine and Cytosine

Question 4

Describe the structure of DNA.

Answer 4

Made upon two strands that are help together by hydrogen bonds formed between complimentary base pairs. These are twisted into a double helix shape. Phosphodiester bonds hold together the nucleotides.

Question 5

Describe the process of transcription

Answer 5

-Takes place in the nucleus.
-An enzyme unwinds the strands of DNA, breaking the hydrogen bonds between complimentary base pairs.
-One o the strands is a template strand, free RNA nucleotides are attracted to their complimentary base pairs and form hydrogen bonds together.
-RNA polymerase Cretes these hydrogen bonds, mRNA is formed and spliced.
-It leaves the nucleus via the nuclear pore and searches for a ribosome.

Question 6

Describe the process of translation

Answer 6

-Takes place in the ribosome
-The mRNA associates with a ribosome
-Each tRNA is specific to an amino acid, the anticodon on it binds to the codon on the mRNA. 2 amino acids form a peptide bond through a condensation reaction.
-process repeats until a stop codon is reached on the mRNA, meaning the full polypeptide hs been formed.
-Polypeptide leaves ribosome and will form a tertiary structure/ associate with another polypeptide.

Question 7

Describe the process of semi-conservative replication

Answer 7

-DNA helices breaks hydrogen bonds that link the base pairs of DNA.
-As a result, the double helix is separated into two strands.
-Each strand then acts as a template and free DNA nucleotides are attracted to their complimentary base pairs and are joined together in a condensation reaction by DNA polymerase.
The strands are wound back together.

Question 8

Watson-Crick model of DNA replication

Question 9

Draw ATP, What are its components?

Answer 9

Adenine- organic base
ribose- 5 carbon ring structure sugar
phosphates- a chain of three phosphate groups

Question 10

Give the equation for the hydrolysis/synthesis of ATP

Answer 10

ATP + h20 = ADP + Pi + E
adenosine triphosphate + water = adenine diphosphate + inorganic phosphate + energy

Question 12

What does DNA stand for?

Answer 12

Deoxyribonucleic acid

Question 13

What are the four DNA bases and RNA bases?

Answer 13

DNA: adenine, thymine, cytosine and guanine
RNA: adenine, uracil, cytosine and guanine

Question 14

describe DNA structure

Answer 14

double helix with a sugar phosphate backbone

Question 15

what is the function of DNA in cells

Answer 15

stores genetic information

Question 16

define transcription

Answer 16

DNA to mRNA conversion

Question 17

what is the function of RNA

Answer 17

protein synthesis messenger

Question 18

name three types of RNA

Answer 18

mRNA
tRNA
rRNA

Question 19

describe the structure of RNA

Answer 19

single stranded nucleotide chain

Question 20

define translation

Answer 20

mRNA to protein conversion

Question 21

name the enzymes involved in DNA replication

Answer 21

DNA helicase
DNA polymerase

Question 22

describe the semi conservation model?

Answer 22

parental strand separation
new synthesis

Question 23

what are replication forks?

Answer 23

y shaped regions of replication

Question 24

what are the roles of the enzymes in replication?

Answer 24

DNA polymerase: builds new DNA strands
DNA helicase: unwinds the DNA double helix

Question 25

define the leading strand

Answer 25

continuous DNA synthesis strand