Chapter 7

Question 1

4 Nucelotides

Answer 1

Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G

Question 2

Genome

Answer 2

complete set of genetic information
Chromosome plus technically plasmids
All cells: DNA
Viruses may have RNA
Functional unit is gene
Encodes gene product, usually a protein
Study of nucleotide sequence is genomics

Question 3

2 Tasks cell must do to multiply

Answer 3

1.Dna Replication
2. Gene Expression (transcription and translation)
DNA-RNA-Protein

Question 4

DNA doublestranded helix is jioned by

Answer 4

5’PO4 and 3’OH, forms sugar phosphate backbone.

Single strand will have 5’ and 3’ end. Strands are complementary and antiparallel

Question 5

How are strands held together?

Answer 5

Hydrogen bonds between nucleobases

Question 6

How many hydrogen bonds in base pair AT and CG

Answer 6

AT-2

CG-3

Question 7

Melting/Denaturing

Answer 7

separating of strands

Question 8

RNA characteristics

Answer 8

Uracil instead of thymine, shorter strand and synthesized from DNA template strand

Question 9

3 types of required gene expression for RNA

Answer 9

Messenger RNA mrna
Ribosomal rRna
Transfer RNA trna

Question 10

Dna characteristics

Answer 10

creates two replication forks. replicatoin is semiconservative, dna contains 2 original, new synthesized stran,
replication begins in origin of replication

Question 11

Steps in Dna Replicatoin

Answer 11

1. Untwisting the DNA strand and forming a replication fork
   Enzyme: helicase (unwinds the strands), single-strand binding proteins to help stabilize the strand
2. Untangling the DNA strands
   Enzyme: topoisomerase (breaking and rejoining the strands)
3. Adding nucleotides to the leading strand
   Enzyme: DNA polymerase III (adding nucleotides from the RNA primer), primase (to produce primers at 5’ end)
4. Adding nucleotides to the lagging strand
   Enzyme: primase (produces primers at each Okazaki fragment), DNA polymerase I and III
5. Rejoining the strands
   Enzyme: DNA ligase (rejoins the Okazaki fragment

Question 12

Replisomes

Answer 12

“assembly line” complex of enzymes and other proteins that synthesize dna

Question 13

Dna Gyrase

Answer 13

breaks strands of dna, releiving tensions

Question 14

Dna Ligase

Answer 14

joins two dna fragments by covalent bonds

Question 15

DNA Polymerase

Answer 15

enzymes that synthesize dna, use one strand of dna as a template to make another complementary strand. New nucleotides are added only at the 3’end, occurs 5’to3’ direction

Question 16

Helicases

Answer 16

Unwind dna strand ahead of replication fork

Question 17

Okazaki fragments

Answer 17

fragments produced during discontinous synthesis of lagging strand

Question 18

Origin of replication

Answer 18

region where dna molecules are being replicated

Question 19

Primase

Answer 19

enzymes that synthesize fragments of RNA to serve as primers for dna synthesis

Question 20

Primer

Answer 20

framgents of nucleic acid to which dna polermase can add nucleotides

Question 21

Leading strands

Answer 21

synthesized continously

Question 22

Lagging Strands

Answer 22

synthesize discontinously, production of Okazaki fragments, different dna polyermase replace primers

Question 23

Transcription

Answer 23

Rna polyermase synthesizes single strand rna, uses dna template and synthesizes 5’3’ direction
can initiate without primer
Binds to promoter-found upstream of genes and stops at Terminator-transcription ends

Question 24

Promoter

Answer 24

nucleotide sequence eto which rna polymerase binds to initiate transcriptions

Question 25

3 steps in Transcription

Answer 25

1. Initiation, RNA polyermase binds to the promoter and mets a shoot stretch of dna,
2. Elongation, Sigma factor dissociates from RNA polymerase, leaving the core enzyme to complete transcription.
3. Termination: RNA polymerase finds terminator, falls off the template and releases new Rna

Question 26

TRNA job

Answer 26

delivery correct amino acid, acts as a key that interprets the genetic code,

Question 27

Translation in prokayries

Answer 27

Begings before transcription is complete