Chapter 4 vocab

Question 1

complimentary base pairing

Answer 1

hydrogen bonding between purines (a and t), and pyrimidines (c and g)

Question 2

DNA helicase

Answer 2

enzyme that unwinds the DNA strands by breaking H-bonds between base pairs

Question 3

DNA polymerase

Answer 3

enzyme that positions and joins new complimentary DNA nucleotides into place during DNA replication

Question 4

nucleotide

Answer 4

a molecular complex of three subunits; phosphate, pentose sugar and a nitrogen containing base

Question 5

recombinant DNA

Answer 5

contains DNA from two or more different sources

Question 6

replication

Answer 6

the process of copying one DNA helix into two identical helices

Question 7

semi-conservative replication

Answer 7

after DNA replication, a new double helix has one conserved old template strand and one new strand

Question 8

amino acid

Answer 8

an organic molecule composed of an amino group and an acidic group

Question 9

anti-codon

Answer 9

a triplet of three bases complimentary to the mRNA codon

Question 10

codon

Answer 10

a triplet nucleotides in mRNA that either codes for a particular amino acid or signals polypeptide termination

Question 11

DNA sequence

Answer 11

a succession of letters that indicate the order of nucleotides within a DNA molecule

Question 12

elongation

Answer 12

the second step of protein synthesis where the polypeptide chain is created one amino acid at a time

Question 13

environmental mutagen

Answer 13

environmental influences that cause mutations in humans

Question 14

genetic disorder

Answer 14

an illness caused by one or more abnormalities in the genome i.e. sickle cell mutation

Question 15

initiation

Answer 15

first step of protein synthesis, all translation components are brought together

Question 16

mRNA function

Answer 16

a RNA molecule is formed by copying DNA (with uracil instead of thymine). RNA travels through the nuclear pores to the ribosome where proteins are formed.

Question 17

mutation

Answer 17

a permanent change in the sequence in the sequence of bases in the DNA; either germ-like or somatic

Question 18

polypeptide chain

Answer 18

a chain of amino acids that are joined by peptide bonds

Question 19

ribosomes

Answer 19

composed of two subunits, involved in synthesis of proteins using mRNA as a template

Question 20

termination

Answer 20

final step of protein synthesis, polypeptide and assembled components that carried out protein synthesis are separated from one another

Question 21

transcription

Answer 21

the first step of gene expression; process where ta portion of DNA serves as a template for mRNA formation

Question 22

tRNA

Answer 22

a nucleic acid containing a sugar ribose responsible for bringing the amino acid to the ribosome for protein formation

Question 23

translation

Answer 23

during gene expression, the process where the sequence of mRNA bases determine the sequence of amino acids in a polypeptide