-1B: DNA + RNA

Question 1

what does DNA stand for?

Answer 1

deoxyribonucleic acid

Question 2

function of DNA?

Answer 2

-codes for amino acid sequence in primary structure of a protein
-in turn determining the 3D structure of a tertiary structure protein

Question 3

what structure is DNA?

Answer 3

double helix

Question 4

polymer -> monomer of DNA?

Answer 4

polynucleotide -> nucleotide

Question 5

what is a nucleotide comprised of?

Answer 5

-phosphate group
-nitrogen base (adenine, thymine, cytosine, guanine)
-ribose sugar (deoxyribose)

Question 6

how is a polynucleotide formed?

Answer 6

-condensation reactions releasing a molecule of water between deoxyribose sugar and phosphate group of nucleotides
-forming a phosphodiester bond -> strong + covalent

Question 7

why are phosphodiester bonds strong + covalent?

Answer 7

to ensure genetic code doesn’t isn’t broken down

Question 8

what does a polynucleotide contain? what is it?

Answer 8

-sugar phosphate backbone
-describes the strong covalent bonds between the phosphate + deoxyribose that hold polymer in place

Question 9

DNA polymers occur in pairs…

Answer 9

-with weak hydrogen bonds between bases
-these chains twist -> double helix structure

Question 10

what can hydrogen bonds only form between?

Answer 10

-complementary bases
-A-T= 2 hydrogen bonds
-C-G= 3 hydrogen bonds

Question 11

why is complementary base pairing important?

Answer 11

to maintain order of genetic code when DNA replicates

Question 12

state + explain how the structures of DNA relates to their function

Answer 12

-stable structure -> sugar phosphate backbone (covalent bonds) + double helix
-weak hydrogen bonds -> easy unzipping between strands during DNA replication
-double strand -> one strand can act as template strand during DNA replication
-large molecule -> large amount of information can be transferred
-complementary base pairing -> allows for identical copies to be made

Question 13

what is the monomer of RNA? describe it

Answer 13

-nucleotide
-contains phosphate group, ribose sugar, bases
-> uracil (instead of thymine), cytosine -> adenine

Question 14

function of RNA?

Answer 14

copy + transfer genetic code from DNA in nucleus -> ribosomes

Question 15

structure of RNA?

Answer 15

-short stranded polynucleotide
-singe stranded

Question 16

RNA can also be combined with other proteins to create what?

Answer 16

ribosomes

Question 17

three types of RNA + what they stand for?

Answer 17

-mRNA, messenger
-tRNA, transfer
-rRNA, ribosomal

Question 18

mRNA?

Answer 18

-copy of a gene of DNA
-created in nucleus + leaves nucleus to carry a copy of genetic code for one gene to ribosomes in cytoplasm
-DNA is too large to leave nucleus + risk of being damaged by other enzymes -> would permanently damage genetic code
-short lived- only temporarily helps in creating proteins, by the time enzymes have broken it down -> already carried out its function
-single stranded -> every 3 bases in sequence -> coding for one specific amino acid -> ‘codon’

Question 19

tRNA?

Answer 19

-found only in cytoplasm
-single stranded -> folded into clover leaf shape, held together by hydrogen bonds
-attach to one of 20 amino acids + tranfers specific amino acid to ribosome to create polypeptide chain
-specific amino acids attach to specific tRNA molecules due to 3 bases found on tRNA which are complementary to 3 bases found in mRNA
-called anti-codon as complementary to codon on mRNA

Question 20

rRNA?

Answer 20

-type of RNA that makes up the bulk of ribosomes
-30S + 50S
-70S complete ribosome

Question 21

difference between DNA + RNA monomers?

Answer 21

-RNA = deoxyribose sugar instead of ribose in RNA
-RNA base uracil replacing thymine base in DNA

Question 22

difference between DNA + RNA polymers?

Answer 22

-RNA = single stranded, DNA = double stranded
-DNA much larger, contains approc 23k genes (genome), RNA much shorter because its the length of one gene

Question 23

define genome

Answer 23

the complete set of genes in a cell