A1.2 Nucleic Acids

Question 1

2 main functions of nucleic acids

Answer 1

• pass information between generations
• code for protein production

Question 2

types of nucleic acids

Answer 2

dna rna

Question 3

types of RNA

Answer 3

tRNA - transfer
rRNA - ribosome
mRNA - messenger

Question 4

main role of Dna

Answer 4

carries genetic code in all living organisms
passes hereditary information between generations of cells

Question 5

main role of rna

Answer 5

protein synthesis
codes for making protein

Question 6

difference between nucleotide bases in RNA and DNA

Answer 6

A C G is the same
in RNA the T is replaced by a U

Question 7

structure of nucleotides

Answer 7

pentose sugars

Question 8

structure of DNA

Answer 8

double helix

Question 9

difference in DNA and RNA structure

Answer 9

there is an extra oxygen in 2’ of RNA

Question 10

Components of a nucleotide

Answer 10

A pentose sugar (a sugar with 5 carbon atoms)
A nitrogen-containing organic base (with either 1 or 2 rings of atoms)
A phosphate group (this is acidic and negatively charged)

Question 11

purine bases

Answer 11

Adenine and guanine are purine bases

Question 12

pyrimidine bases

Answer 12

Cytosine, thymine (in DNA) and uracil (in RNA) are pyrimidine bases

Question 13

how are the two strands in DNA connected

Answer 13

hydrogen bonds connecting the nucleotide bases

Question 14

structure of purines

Answer 14

double ringed structures

Question 15

structure of pyramidines

Answer 15

single ringed structures

Question 16

how many bonds do A & T have in between them

Answer 16

2 hydrogen bonds

Question 17

how many bonds do C & G have in between them

Answer 17

3 hydrogen bonds

Question 18

what is the backbone

Answer 18

sugar - phosphate

Question 19

polynucleotides

Answer 19

phosphate group of one nucleotide forms a covalent bond to the pentose sugar of the next one

a long unbranched chain of nucleotides as found in DNA and RNA

Question 20

how are the phosphate groups linked

Answer 20

condensation reaction

Question 21

where is (mRNA) formed and transported

Answer 21

formed in the nucleus and transported to the ribosomes in the cytoplasm

Question 22

what is transfer RNA resposible for (tRNA) - function

Answer 22

which is responsible for transporting amino acids to ribosomes during protein synthesis

Question 23

ribosomal RNA (rRNA)

Answer 23

forms part of ribosomes

Question 24

anti parallel

Answer 24

DNA molecules are made up of two polynucleotide strands lying side by side, running in opposite directions

Question 25

direction of strands in dna

Answer 25

**5'-3'** 3'-5' - antiparallel

Question 26

what does 5' end with

Answer 26

phosphate

Question 27

what does 3' end with

Answer 27

pentose

Question 28

what creates structural support In back bone and why is it necessary?

Answer 28

sharing of electron in the covalent bond between sugar and phosphate - provides strength to structure strength maintains nucleotides in their specific sequence which is necessary for storing, replication and expression of genetic information

Question 29

what is complementary base pairing

Answer 29

A with T C with G allows genetic information to be replicated and expressed

Question 30

a

Answer 30

adenine

Question 31

t

Answer 31

thymine

Question 32

c

Answer 32

cytosine

Question 33

u

Answer 33

uracil

Question 34

g

Answer 34

guanine

Question 35

genetic code

Answer 35

the order of bases in DNA that determines the sequence of amino acids in a protein

Question 36

coding strand

Answer 36

the strand that will carry the base sequence to be read by enzymes

Question 37

codon

Answer 37

triplet of bases which codes for one animo acid

Question 38

how many bases code for one amino acid

Answer 38

3

Question 39

how many amino acids are there

Answer 39

20

Question 40

gene

Answer 40

heritable factor that consists of a length of DNA that codes for a protein

Question 41

chromosome

Answer 41

length of DNA that carries specific genes in a linear sequence

Question 42

locus

Answer 42

particular position of a gene on the homologous chromosomes

Question 43

what does the sequence of amino acids determine

Answer 43

determine the shape and function of the protein that is synthesised from the code

Question 44

The genetic code is universal

Answer 44

meaning that almost every organism uses the same code (there are a few rare and minor exceptions)

Question 45

allele

Answer 45

different versions of the same gene alternative form

Question 46

homologous chromosomes

Answer 46

pairs of chromosomes one from each parents that carry the same sequences of genes

Question 47

genome

Answer 47

whole of the genetic information of an organism or cell

Question 48

mutation

Answer 48

a change in the amount or the structure of DNA of a chromosome

Question 49

process of decoding a gene consists of

Answer 49

transcription translation

Question 50

transcription

Answer 50

formation of mRNA molecules from the DNA that makes up a particular gene. first stage of protein synthesis

Question 51

translation

Answer 51

the later part of protein synthesis when the mRNA is used as a template to which complementary tRNA molecules attach and the amino acids link to form a polypeptide

Question 52

where is DNA found

Answer 52

nucleus - eukaryotic cell nucleic or plasmids - prokaryotic can be found in mitochondria and chloroplasts as well

Question 53

where is RNA found

Answer 53

made in nucleus during transcription and then transported to cytoplasm

Question 54

complementary base pairing meaning

Answer 54

base sequence on one DNA strand determines the sequence of the other strand

Question 55

what does complimentary base pairing allow

Answer 55

allows DNA to be copied very precisely during DNA replication which in turn ensures that the genetic code is accurately copied and expressed in newly formed cells

Question 56

dna storage ability and why

Answer 56

limitless capacity to store information because there is a very diverse range of DNA base sequences in DNA molecules of different lengths