Dna

Question 1

what is dna made of

Answer 1

phosphate group , pentose sugar (deoxyribose) and a nitrogen-containing base

Question 2

how are the nucleotides joined together?

Answer 2

my phosphodiester bonds between the sugar and another nucleotides phosphate group by condensation

Question 3

what is DNA polymerase

Answer 3

an enzyme which creates the phosphodiester bond

Question 4

describe the structure of DNA

Answer 4

a double helix structure which has two polynucleotide chains joined by hydrogen bonds between the base pairs

Question 5

describe the bonding between the bases

Answer 5

adenine forms 2 hydrogen bonds with thymine and guanine forms 3 hydrogen bonds between cytosine

Question 6

what does anti parallel mean ?

Answer 6

the strands run in opposite directions of each-other
one strand starts with C5 and ends with C3
another starts with C3 and ends with C5
Reads it in the 5 to 3 direction

Question 7

what is the function DNA replication

Answer 7

to create more copies so that when cells divide they have exact copies of DNA

Question 8

what is the function of protein synthesis?

Answer 8

contains genes which code for the order of amino acids in a protein

Question 9

describe the structure of DNA and its advantages

Answer 9

long - stores a lot of information
helical - compact
double stranded - each stand acts as a template for DNA replication
sugar phosphate backbone - provides strength and stability and protects the bases within the helix
weak hydrogen bonds- easily broken and unzipped for DNA replication or protein synthesis
lots of hydrogen bonds - makes the molecule stable and strong

Question 10

describe the nucleotide of RNA

Answer 10

single molecule , relatively short
made up of phosphate group , ribose pentose sugar and nitrogen containing base

Question 11

describe mRNA and its role in

Answer 11

single stranded straight chain molecule made of bases which are read in co-dons
role is to carry the genetic code out of the nucleus to the ribosome for the formation of 1 polypeptide chain

Question 12

describe tRNA and its role

Answer 12

single strand of RNA folded into many places forming complementary base pairs
cover leaf shape
has an amino acid binding site and a triplet of bases called an anticodon complementary to mRNA codon
role is to carry specific amino acids to the mRNA at ribosomes for formation of polypeptide chain

Question 13

describe RRNA and its role

Answer 13

rRNA is found in the cytoplasm
role- along with a protein molecule it forms ribosomes

Question 14

DNA VS RNA

Answer 14

DNA
two strands
very long
thymine
stores genetic information
RNA
one strand
relatively short
uracil
transfers genetic information in the formation of proteins and helps form ribosomes

Question 15

what’s the stage during the cell cycle where DNA replication happens

Answer 15

interphase

Question 16

what does semi conservative mean?

Answer 16

means that each strand acts as a template and that each new molecule of dna contains one original strand and one new

Question 17

DNA helicase

Answer 17

unwinds DNA and breaks hydrogen bonds between bases allowing nucleotides to attach to each strand and for each stand to act as a template

Question 18

DNA polymerase

Answer 18

joines adjacent nucleotides together forming phosphodiester bonds in the sugar-phosphate backbone

Question 19

stages of DNA replication

Answer 19

1. dna helicase separates DNA by breaking hydrogen bonds
2. each strand acts as template
3. free nucleotides attach to the exposed bases by complementary base pairing
4. DNA polymerase joins nucleotides forming a phosphodiester bond

Question 20

how is DNA replicated direction wise

Answer 20

5th carbon to 3rd carbon
polymerase enzymes have an active site which is complimentary and specific to the 3rd carbon end of the chain
this means that new nucleotides are added in the 5th carbon to 3rd carbon direction