structure of DNA and RNA

Question 1

what is DNA?

Answer 1

the hereditary material in human and almost all other organisms

Question 2

where is DNA located?

Answer 2

most in the cell nucleus but some is found in the mitochondria

Question 3

how is the information in DNA stored?

Answer 3

in codes

Question 4

what are the four chemical bases?

Answer 4

-adenine (A)
-guanine (G)
-cytosine (C)
-thymine (T)

Question 5

what bases pair up with each other?

Answer 5

A and T
C and G

Question 6

what are the pairs called?

Answer 6

base pairs

Question 7

each base is also attached to a what and a what?

Answer 7

a sugar molecule and a phosphate molecule

Question 8

together, a base, sugar and phosphate are called a what?

Answer 8

nucleotide

Question 9

how are nucleotides arranged?

Answer 9

in two long strands that form a spiral called a double helix, base pairs form horizontal rungs, the sugar and phosphate molecules form the vertical side pieces

Question 10

what is an important property of DNA?

Answer 10

that it can replicate/make copies of itself

Question 11

each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases, this is critical when cells divide because…

Answer 11

because each new cell needs to have an exact copy of the DNA present in the old cell

Question 12

what three components are nucleotides made up of?

Answer 12

-deoxynbase
-phosphate group
-nitogen containing organic base

Question 13

what is a deoxynbase?

Answer 13

a pentose sugar, has 5 carbon atoms

Question 14

how are nucleotides formed?

Answer 14

by a condensation reaction between their three component parts (a mono nucleotide)

Question 15

what is RNA?

Answer 15

contains the sugar ribose (another pentose)

Question 16

what is DNA made up of?

Answer 16

two polynucleotide strand joined together by hydrogen bonds formed between the bases on each nucleotide

Question 17

adenine and thymine always join together using what?

Answer 17

two hydrogen bonds

Question 18

cytosine and guanine alway join together using what?

Answer 18

three hydrogen bonds

Question 19

what are the two distinct ends of a polypeptide chain?

Answer 19

three prime end (3’)
five prime end (5’)

Question 20

each base pair is how long apart?

Answer 20

0.34 nm

Question 21

what is a phosphdiester bon?

Answer 21

a bond between a sugar group and a phosphate group

Question 22

what is a polypeptide chain?

Answer 22

a string of amino acids connected together by peptide bonds

Question 23

what are deoxyribose molecules?

Answer 23

a pentose (5 carbon sugar) biological molecule

Question 24

what is a phosphate group?

Answer 24

a functional group characterised by a phosphorus atom bonded to four oxygen atoms (three single bonds and one double bond)

Question 25

what is a cistron?

Answer 25

a sequence of bases that is the equivalent to one gene

Question 26

what is a locus?

Answer 26

on a molecule of DNA each particular gene (cistron) occupies a specific position

Question 27

what are alleles?

Answer 27

different forms of the same genes

Question 28

what is RNA?

Answer 28

a similar material to DNA, it is made up of a pentose sugar, a phosphate group and one of four bases. the RNA bases are slightly different from DNA which has uracil instead of thymine

Question 29

what is uracil?

Answer 29

uracil bonds to adenine in the same way that thymine does in DNA. Unlike DNA, RNA is just single polynucleotide strand

Question 30

what is messenger RNA (mRNA) responsible for?

Answer 30

transcription

Question 31

what happens during transcription? and what happens during the process?

Answer 31

the DNA helix splits and unwinds, the process is catalysed by the enzyme RNA polymerase

Question 32

what is a polynucleotide?

Answer 32

a combination of nucleotide monomers which are connected to each other through covalent bonds

Question 33

what are introns?

Answer 33

non coding regions of the gene that do not contain codons needed to make the final protein AND are found between exons

Question 34

what is splicing?

Answer 34

biological process where a newly synthesised pre-mRNA is transformed into a mature mRNA OR in splicing, some sections of RNA transcript (introns) are removed and the remaining sections (exons) are stuck back together

Question 35

what are exons?

Answer 35

a sequence of DNA that codes for an amino acid sequence.

Question 36

what is mRNA?

Answer 36

a type of RNA molecule that carries the genetic information from DNA to the ribosome, where it is used to make proteins

Question 37

the mature mRNA molecule then exits the nucleus and is transported to a what?

Answer 37

ribosome

Question 38

the mRNA then combines with the ribosome, here it directs the the next process in what?

Answer 38

polypeptide synthesis translation