2.3 Nucleic Acids

Question 1

genes

Answer 1

a sequence of nucleotide bases that codes for one (or more) polypeptides

Question 2

polypeptide

Answer 2

a larger polymer molecule made by many amino acids joined by peptide bonds

Question 3

human genome

Answer 3

25,000 genes, most found on the linear chromosomes within the nucleus, each gene occupies a specific locus on the chromosome, DNA in chromosome associated with histone proteins

Question 4

the genetic code

Answer 4

the sequence of nucleotide bases on a gene provides a code, with instructions for the construction of a polypeptide or protein

Question 5

DeoxyriboNucleic Acid (DNA)

Answer 5

contains instructions on how to build proteins used in the body, found in cell nucleus, codes for individual proteins, made up from chain of sugar-phosphates and one of four bases

Question 6

protein

Answer 6

polymer of units linked by peptide bonds, built up from 20 amino acids, created in ribosomes, perform nearly all biological functions

Question 7

messenger RNA

Answer 7

an intermediary form that dna uses to build protein in ribosomes outside the nuclear envelope as molecules are too large to escape the nucleus

Question 8

where are the nucleotides in transcription from

Answer 8

there are free dna nucleotides in the nucleoplasm and free rna nucleotides in the nucleolus

Question 9

base triplet

Answer 9

a triplet of bases on a dna molecule

Question 10

codon

Answer 10

a triplet of bases on a length of mRNA

Question 11

anticodon

Answer 11

a triplet of bases on a tRNA molecule complementary to the mRNA codon

Question 12

nucleotides

Answer 12

biological molecules that participate in nearly all biochemical processes

Question 13

RNAs nucelotide pentose sugar

Answer 13

ribose

Question 14

DNAs nucleotide pentose sugar

Answer 14

deoxyribose

Question 15

phosphodiester bond

Answer 15

covalent bond formed between sugar residue and phosphate group in nucleotide of DNA formed when polynucleotides synthesise

Question 16

examples of a purine (nitrogenous base)

Answer 16

adenine

guanine (2 rings)

Question 17

examples of a pyrimidine (nitrogenous base)

Answer 17

thymine

cytosine (1 ring)

Question 18

how bonds in DNA are formed

Answer 18

2 antiparallel DNA strands joined by hydrogen bonds between the nitrogenous bases

Question 19

semi-conservative replication

Answer 19

a product of 2 DNA molceules, identical to each and parent, containing 1 old strand and 1 new strand

Question 20

precipitation

Answer 20

when salty DNA becomes undissolved as it comes into contact with alcohol (DNA normally stays dissolved in water)

Question 21

in DNA what does Adenine pair with

Answer 21

Thymine

Question 22

in DNA what does Guanine pair with

Answer 22

Cytosine

Question 23

in DNA what does Thymine pair with

Answer 23

Adenine

Question 24

in DNA what does Cytosine pair with

Answer 24

Guanine

Question 25

how many hydrogen bonds between A and T

Answer 25

2

Question 26

how many hydrogen bonds between G and C

Answer 26

3

Question 27

the 5' end

Answer 27

where the phosphate group is attached to the 5th carbon molecule on the five-carbon sugar (deoxyribose)

Question 28

the 3' end

Answer 28

where the phosphate group is attached to the 3rd atom of the sugar (deoxyribose)

Question 29

function of gyrase

Answer 29

an enzyme that catalyses the process of the double helix untwisting a bit at a time to unwind each DNA molecule

Question 30

function of helicase

Answer 30

enzyme that catalyses breaking of hydrogen bonds between the nucleotide bases to unzip DNA molecule

Question 31

double helix

Answer 31

shape of DNA molecule, due to coiling of the 2 sugar-phosphate backbone strands into a right-handed spiral configuration

Question 32

polynucleotide

Answer 32

large molecule containing many nucleotides

Question 33

DNA polymerase

Answer 33

enzyme that catalyses formation of DNA from activated deoxyribose nucleotides using single-stranded DNA as a template

Question 34

transcription

Answer 34

the process of making messenger RNA from a DNA template

Question 35

translation

Answer 35

formation of a protein(polypeptide) by assembling amino acids into a particular sequence at ribosomes- according to the coded instructions carried from DNA by mRNA

Question 36

the starter codon of a polypeptide chain

Answer 36

AUG

Question 37

bond between 2 adjacent amino acids

Answer 37

peptide

Question 38

bond between codons and anticodons

Answer 38

hydrogen