CPA #11 Questions

Question 1

define: 5 prime

Answer 1

the 5’ end terminates in a phosphate group attached to a 5’ carbon

Question 2

define: 3 prime

Answer 2

the 3’ end terminates with a hydroxyl group bound to a 3’ carbon of deoxyribose

Question 3

define: antiparallel

Answer 3

one strand runs 5’-3’ and the other strand runs 3’-5’

Question 4

define: plasmids

Answer 4

• small molecules of DNA that replicate separate from chromosomes
• 1%-20% the size of a chromosome
• not essential for normal metabolism, growth, or cellular respiration

Question 5

what are the 4 types of plasmids?

Answer 5

1. fertility plasmids
2. resistance plasmids
3. bacteriocin plasmids
4. virulence plasmids

Question 6

define: fertility plasmids

Answer 6

carry instructions for conjugation; the transfer if DNA to other bacterial cells

Question 7

define: resistance (R) plasmids

Answer 7

carry genes for resistance to one or more antimicrobial drugs or heavy metals

Question 8

define: bacteriocin plasmids

Answer 8

carry genes for proteinaceous toxins called bacteriocins (kill bacterial cells of the same species that lack the plasmids)

Question 9

define: virulence plasmids

Answer 9

carry instructions for structures, enzymes, or toxins that enable a bacterium to become pathogenic.

Question 10

explain how eukaryotic genomes consist of both nuclear and extranuclear DNA

Answer 10

eukaryotes also have mitochondria (or chloroplasts) which are outside of the nucleus and they contain chromosomes.

Question 11

define: histones

Answer 11

positively charged; stabilize and package DNA.

Question 12

define: nucleosomes

Answer 12

negatively charged DNA wraps around a positively charged histone protein to form a 10-nm-diameter bead

Question 13

define: chromatin fibers

Answer 13

nucelosomes clump with other proteins; dispersed throughout the nucleus

Question 14

define: euchromatin

Answer 14

active DNA; loosely packed chromatin fibers

Question 15

define: heterochromatin

Answer 15

inactive DNA; tightly packed chromatin fibers

Question 16

explain how DNA replication is an anabolic polymerization process

Answer 16

adding nucleotides to the end

Question 17

define: genotype

Answer 17

actual set of genes inside genome; consists of all the series of DNA nucleotides that carry instructions for an organisms life

Question 18

define: phenotype

Answer 18

refers to the physical features and functional traits of an organism (structure, function, morphology)

Question 19

define: RNA primer

Answer 19

molecules for DNA polymerase to use during DNA replication

Question 20

define: mRNA

Answer 20

messenger; carry genetic info from chromosomes to ribosomes

Question 21

define: rRNA

Answer 21

ribosomal; combine with ribosomal polypeptides to form ribosomes (organelles that synthesize polypeptides)

Question 22

define: tRNA

Answer 22

transfer; which deliver the correct amino acids to ribosomes based on the sequence of nucleotides in mRNA

Question 23

how is mRNA processed before translation?

Answer 23

• undergoes polyadenylation
• ribosomes remove introns and splice together exons
• forms a molecule that codes for a single polypeptide

Question 24

how is DNA replication semiconservative?

Answer 24

take old strand and rip it open (creating two separate strands) and act as a template to build a new complementary strand to match (two new complementary strands)

Question 25

summarize the process of transcription

Answer 25

1. initiation of transcription
2. elongation of RNA transcript
3. termination of transcription (release RNA polymerase by one of 2 methods)

Question 26

what are the 2 ways to terminate transcription?

Answer 26

1. self-termination
2. Rho-dependent termination

Question 27

summarize DNA replication

Answer 27

1. Initial process
2. synthesis of leading strand (continuous)
3. synthesis of lagging strand (discontinuous)

Question 28

define initial process (DNA)

Answer 28

cell removes proteins from the DNA molecule; helicase unzips double helix

Question 29

define: continuous synthesis (leading strand)

Answer 29

synthesis toward the replication fork (5’ toward 3’)

Question 30

define: discontinuous synthesis (lagging strand)

Answer 30

synthesis away from the replication fork (3’ toward 5’)