Exam #3

Question 1

most important macromolecule for the continuity of life;

carry genetic material and instructions for functions

Answer 1

nucleic acid

Question 2

synthesis of mRNA–>movement of mRNA into the cytoplasm–>synthesis of protein

Answer 2

gene expression

Question 3

The DNA molecules never leave the nucleus but instead use this intermediary to communicate with the rest of the cell

Answer 3

messenger RNA (mRNA)

Question 4

components of nucleotides

Answer 4

a nitrogenous base, a pentose (five-carbon) sugar, and a phosphate group

Question 5

adenine and guanine

Answer 5

purines

Question 6

cytosine, thymine, and uracil

Answer 6

pyrimidines

Question 7

The relationship between proteins and genes

Answer 7

protein’s primary structure is determined by genes

Question 8

Characteristics of DNA

Answer 8

double-stranded, adenine,thymine, guanine, cytosine, deoxyribose sugar, genetic info

Question 9

Characteristics of RNA

Answer 9

single-stranded, adenine, uracil, cytosine, guanine

Question 10

Characteristics of DNA being double-stranded

Answer 10

two strands run antiparallel to each other; complementary to each other and form the structure of DNA; each stores the info necessary to reconstruct the other

Question 11

Applications of DNA in everyday life

Answer 11

genetic testing, GMO, used to determine evolutionarily relationships

Question 12

Experiment done to determine that DNA is genetic material:

Answer 12

• used streptococcus pneumonia
• infected mice with living S cells (pathogenic, killed the mice)
• infected mice with living R cells (nonpathogenic, did not kill the mice)
• Infected mice with heat killed s cells (did not kill the mice)
• Infected mice with mixture of heat killed S cells and living R cells (killed the mice)

Question 13

Bacteriophage

Answer 13

a virus that infects bacteria

Question 14

Bacteriophage Experiment:

Answer 14

• radioactive protein and DNA were tested to see if protein or DNA was caused the bacteria to be infected
• radioactive protein was not found inside the cell
• radioactive DNA was found to be inside the cell

Question 15

Helicase

Answer 15

enzymes that untwist the double helix at the replication forks, separating the parents strands

Question 16

Single-Stranded Binding Protein

Answer 16

Bind to unpaired DNA strands, prevent them from re-pairing

Question 17

Topoisomerase

Answer 17

Enzymes that help relieve the strain of twisting DNA

Question 18

Primase

Answer 18

synthesize RNA primers, which start the new strand

Question 19

DNA Polymerase III

Answer 19

enzymes that synthesize new DNA strands by adding nucleotides to the 3’ end of pre-existing chain, MAIN DNA POLYMERASE

Question 20

DNA Polymerase I

Answer 20

enzymes that synthesize new DNA strands by adding nucleotides to the 3’ end of a pre-existing chain, fills in DNA where RNA primers were

Question 21

DNA ligase

Answer 21

Joins Okazaki fragments together

Question 22

Mismatch Repair

Answer 22

enzymes remove and replace incorrectly paired nucleotides that have resulted from replication errors

Question 23

Damage Repair

Answer 23

DNA is repaired outside of replication

Question 24

Telomerase

Answer 24

enzyme that lengthens telomeres

Question 25

Histones

Answer 25

small proteins that contain a lot of positively charged amino acids that bind to the negatively charged DNA

Question 26

Heterochromatin

Answer 26

highly condensed chromatin during interphase

Question 27

Euchromatin

Answer 27

loosely compacted chromatin that is accessible to transcription machinery

Question 28

Genetic Code

Answer 28

- 4 nucleotides --> need to encode 20 amino acids - 3 nucleotides encode 1 amino acid = CODON - our bodies can read DNA sequences from other organisms

Question 29

RNA Splicing

Answer 29

modification of RNA after transcription

Question 30

Non-coding regions; intervening (get spliced out);

Answer 30

introns

Question 31

coding regions; expressing so they are left it

Answer 31

exons

Question 32

Point Mutation

Answer 32

replacing one nucleotide

Question 33

Insertions

Answer 33

inserting a nucleotide or nucleotides

Question 34

Deletions

Answer 34

deleting a nucleotide or nucleotides

Question 35

Nucleotide pair substitutions

Answer 35

replacement of one nucleotide pair and its partner with another pair of nucleotides

Question 36

Gene Expression

Answer 36

which genes are turned on and off

Question 37

Gene expression does not occur when

Answer 37

chromatin is tightly packed

Question 38

Gene expression does occur when

Answer 38

chromatin is loosely packed

Question 39

Promoters

Answer 39

The region directly in front of the start (ATG) of a gene that regulates its expression

Question 40

Enhancers

Answer 40

The region not directly in front of the start of a gene that regulates its expression

Question 41

p53

Answer 41

this protein is a transcription factor (mutated in 50% cancer)