Gene Function

Question 1

Prototrophic strain

Answer 1

can grow on minimal medium (is
able to make its own arginine and other amino acids)

Question 2

Auxotrophic strain

Answer 2

requires nutritional supplementation

Question 3

One Gene-One Polypeptide Hypothesis

Answer 3

an extension based on the
fact that not all proteins are made of up one polypeptide subunit

Question 4

Two Key Processes in Gene Function

Answer 4

Transcription and Translation

Question 5

Function of a Gene

Answer 5

our genes contain instructions that tell your cells to make molecules called proteins.

Question 6

One Gene-One Enzyme Hypothesis

Answer 6

genes encode enzymes

Question 7

One Gene-One Protein Hypothesis

Answer 7

an extension based on the fact
that not all proteins are enzymes

Question 8

What process is initiated by the start codon?

Answer 8

the translation of the first amino acid in the polypeptide chain.

Question 9

What process is terminated by the stop codons?

Answer 9

a signal to terminate protein synthesis.

Question 10

In what way is the genetic code “redundant”?

Answer 10

the same amino acid residue can be encoded by multiple, so-called synonymous, codons.

Question 11

In what way is the genetic code “universal”?

Answer 11

every known living organism has genes made of DNA.

Question 12

In what way is the genetic code “non-overlapping”?

Answer 12

one amino acid can be coded by several different codons; however, each codon ONLY codes for one amino acid, not more. Hence the unambiguity of the genetic code.

Question 13

Hershey Chase Experiment

Answer 13

-studied E-Coli
-location of radioactive protein (capsid or intracellular)
-Conclusion: DNA hereditary material

Question 14

Deoxyribonucleotide contains:

Answer 14

deoxyribose sugar, phosphate group, nitrogenous base

Question 15

How do deoxyribonucleotides link?

Answer 15

a hydroxyl group on the 3’ carbon of one deoxyribose and the phosphate group attached to the 5’ carbon of another deoxyribose are joined by a covalent bond (phosphodiester bond)

Question 16

Null alleles

Answer 16

alleles that do not function at all

Question 17

Beadle and Tatum experiment

Answer 17

-used a model organism in their work, mold Neurospora crassa.
-exposed crassa cells to radiation
-analyzed the cells, looking for mutant that failed to make specific compounds.
-inspired the one gene, one enzyme hypothesis.

Question 18

Central Dogma

Answer 18

DNA-> RNA -> Proteins

Question 19

Reading frame

Answer 19

sequence of codons. A single base pair deletion will throw off the whole frame, but a set of three (whole codon) can be removed and still produce functional proteins.

Question 20

Start codon

Answer 20

AUG

Question 21

Stop Codon

Answer 21

UAA, UAG, and UGA

Question 22

Key properties of the genetic code:

Answer 22

-it is redundant
-it is unambiguous
-is non-overlapping
-is nearly universal
-is conservative

Question 23

Point mutations

Answer 23

mutation that alters the sequence of one or a small number of base pairs.

Question 24

missense mutations

Answer 24

point mutations that change the identity of an amino acid in a protein

Question 25

silent mutation

Answer 25

a point mutation that does not change the amino acid sequence of the gene product.

Question 26

frameshift mutation

Answer 26

mutation that shifts the reading frame, usually destroying all function of the protein.

Question 27

nonsense mutation

Answer 27

occur when a codon that specifies an amino acid is changed by mutation to one that specifies a stop codon.

Question 28

Mutation categories of effect:

Answer 28

-Beneficial
-Neutral
-Deleterious

Question 29

Chromosomal mutations

Answer 29

-change in number (aneuploidy)
-change in structure