Gene Expression Glossary

Question 1

Anticodon

Answer 1

Three consecutive bases on the tRNA

Question 2

Codon

Answer 2

Three consecutive bases on the mRNA

Question 3

DNA

Answer 3

Deoxyribose nucleic acid, A joins with T, C joins with G. Double stranded, helix shaped large molecule, a whole chromosome. Deoxyribose sugar.

Question 4

Enzyme

Answer 4

A folded protein which acts as a biological catalyst to speed up the rate of a chemical reaction in an organism.

Question 5

Frameshift

Answer 5

Change in bases that the ribosome reads.

Question 6

Gene

Answer 6

A piece of DNA which codes for the making of a protein / feature.

Question 7

Gene expression

Answer 7

The process where the instructions on our DNA are converted into a functional protein, includes transcription, translation and protein folding.

Question 8

Genotype

Answer 8

The genetic make-up of an organism for a feature.

Question 9

Insertion mutation

Answer 9

A mutation on the DNA where a base(s) is added resulting in a frame shift.

Question 10

Metabolic pathway

Answer 10

A series of enzyme-controlled reactions, where the product of one reaction becomes the substrate of the next.

Question 11

Missense mutation

Answer 11

A change of the base on the DNA which codes for a different amino acid. This may or may not alter the shape of the protein and therefore it’s function.

Question 12

mRNA

Answer 12

Messenger RNA. Made during transcription in the nucleus. Carries the instructions to the ribosome to make a polypeptide change. Contains codons

Question 13

Mutagen

Answer 13

A permanent change in the bases on the DNA

Question 14

Mutation

Answer 14

A permanent change inthe bases on the DNA

Question 15

Non-sense mutation

Answer 15

A change of the base on the DNA which changes the instructions, so a STOP codon occurs in the wrong place. Protein is greatly affected.

Question 16

Peptide bond

Answer 16

Bond formed between 2 amino acids during translation

Question 17

Phenotype

Answer 17

The physical appearance of a new feature

Question 18

Point mutation

Answer 18

A change of only one or a few bases on the DNA

Question 19

Protein

Answer 19

A substance made up of many amino acids joined together to form a polypeptide change, which gets folded into a functional protein (enzymes are a type of protein)

Question 20

Redundancy

Answer 20

The fact that multiple codons code for the same amino acid eg. CCU, CCC, CCA and CCG all code of the amino acid Pro

Question 21

RNA

Answer 21

Ribonucleic acid. A bond with U and G bonds with C. Three types, tRNA, mRNA and rRNA. Single stranded and shorter than DNA. Sugar is ribose

Question 22

Same-sense mutation

Answer 22

A change of the base on the DNA where the bases still code for the same amino acid. This is due to teh redundancy of the genetic code.

Question 23

Silent mutation

Answer 23

A mutation that is neither favourable nor harmful, that remains in a population.

Question 24

Start codon

Answer 24

The start signals on the mRNA which initiates translation. Always AUG

Question 25

Stop codon

Answer 25

These 3 codons on the mRNA (UAA, UAG, UGA) do not code for an amino acid therefore telling the ribosome where to stop translation

Question 26

Substitution mutation

Answer 26

A mutation where the base(s) on the DNA are swapped.

Question 27

Transcription

Answer 27

The process by which DNA going to mRNA, occurs in the nucleus. Controlled by RNA polymerase.

Question 28

Translation

Answer 28

The process by which mRNA going to polypeptide chain, occurs in the cytoplasm on the ribosome.

Question 29

Triplet

Answer 29

Three consecutive bases on the DNA

Question 30

tRNA

Answer 30

Transfer RNA. Carries an amino acid to the ribosome. 3 bases on the mRNA = anticodon