Dna structure function

Question 1

What does DNA stand for

Answer 1

Deoxyribonucleic acid

Question 2

DNA is a type of

Answer 2

Nucleic acid

Question 3

DNA is a found in living cells and is needed to build and carry

Answer 3

to build proteins, which are essential for the proper functioning of cells

DNA and RNA are both important information-carrying molecules, although their functions are slightly different

Question 4

The function of DNA is to

Answer 4

hold or store genetic information

Question 5

DNA is the molecule that contains the

Answer 5

that contains the instructions for the growth and development of all organisms

Question 6

Like DNA, the nucleic acid RNA (ribonucleic acid) is a …………….. – it is made up of many nucleotides linked together in a chain in repeating units

Answer 6

polynucleotide

Question 7

DNA molecules are made up of two

Answer 7

polynucleotide strands lying side by side, running in opposite directions – the strands are said to be antiparallel

Question 8

Each DNA polynucleotide strand is made up of

Answer 8

alternating deoxyribose sugars and phosphate groups bonded together to form the sugar-phosphate backbone.

These bonds are covalent bonds known as phosphodiester bonds

Question 9

The phosphodiester bonds link the

Answer 9

5-carbon of one deoxyribose sugar molecule to the phosphate group from the same nucleotide, which is itself linked by another phosphodiester bond to the 3-carbon of the deoxyribose sugar molecule of the next nucleotide in the strand

Question 10

Each DNA polynucleotide strand is said to have a ……… (these numbers relate to which carbon on the pentose sugar could be bonded with another nucleotide)

As the strands run in opposite directions (they are antiparallel), one is known as the …………..strand and the other is known as the …………. strand

Answer 10

3’ end and 5 ‘ enf

5’ to 3’

3’ to 5’

Question 11

The nitrogenous bases of each nucleotide project ……

Answer 11

out from the backbone towards the interior of the double-stranded DNA molecule

Question 12

The two antiparallel DNA polynucleotide strands that make up the DNA molecule are held together by ……………… between the nitrogenous bases

Answer 12

hydrogen bonds

Question 13

These hydrogen bonds always occur between the same pairs of bases:
The purine adenine(doubelring) (A) always pairs with ……….

and how many hydrogen bonds formed between bases

Answer 13

(single ring)the pyrimidine thymine (T) –

two hydrogen bonds are formed between these bases

Question 14

The purine guanine (G) always pairs with

and how many hydrogen bonds formed between bases

Answer 14

the pyrimidine cytosine (C) –

three hydrogen bonds are formed between these bases

Question 15

The purine adenine (A) always pairs with the pyrimidine thymine (T) – two hydrogen bonds are formed between these bases

The purine guanine (G) always pairs with the pyrimidine cytosine (C) – three hydrogen bonds are formed between these bases

This is known as c

Answer 15

complementary base pairing

These pairs are known as DNA base pairs

Question 16

DNA is described as a double helix
This refers to the

Answer 16

three-dimensional shape that DNA molecules form