Chapter 14 DNA The Genetic Material

Question 1

Functions of DNA

Answer 1

-Long-term storage of genetic information
- Gene: Section of DNA with a specific function (look at notes)
-Chromosome: Long double helix of DNA organized around proteins
-Genome: All of the genetic material (chromosomes) in an organism

Question 2

Nucleotide Composition

Answer 2

Nucleotide Base: Monomer of nucleic acids, Variants: A, T, C, or G
Components of a nucleotide: 5’ carbon of sugar, Phosphate group, Nitrogenous Base: Purine and Pyramidine

Question 3

Primary Structure of DNA

Answer 3

The sequence of nucleotides, nucleotides linked by Covalent (phosphodiester) bonds
1. Phosphate group links 3’ carbon of sugar
2. Creates sugar-phosphate backbone

Question 4

Directionality

Answer 4

5’—>3’
a. Nucleotide bases always added to 3’ end

Question 5

Secondary Structure

Answer 5

Double helix of two DNA strands

Question 6

Nucleotide Pairing

Answer 6

Base pairing: Apairs with T; C pairs with G
Called Chargaff’s rule

Question 7

Antiparallel Configuration

Answer 7

-Strands in a double helix are complementary strands result from base pairing-if you know one, you know the other
- Strands are antiparallel- the run in opposite directions

Question 8

Purpose of Replication

Answer 8

-To copy/synthesis to make
-Purpose: Prepare for cell division by making a copy of genome

Question 9

Copied chromosomes

Answer 9

Held together by a centromere (revisit in cell division)

Question 10

Polymerization Reaction

Answer 10

-Polymerization via dehydration reactions
-Requires Energy: Endergonic reaction, Anabolic reaction (look through notes)

Question 11

Semi Conservative

Answer 11

Each new chromosome contains one original DNA strandand one new DNA strand

Question 12

Origin of replication

Answer 12

Prokaryotes: One origin of replication
Eukaryotes: Many origins per chromosome

Question 13

DNA unwinds from the origin of replication to form a

Answer 13

replication bubble

Question 14

Two Key enzymes of the replisome

Answer 14

Primase and DNA polymerase

Question 15

Primase

Answer 15

1. Adds RNAprimers: Starting nucleotide sequence
2. RNA primers give DNA polymerase a place to start

Question 16

DNA Polymerase

Answer 16

a. Main replication enzymes
b. Adds nucleotides basses in 5’ to 3’ direction
c. That is, always add to 3’ OH
d. RNA primer provides starting 3’OH

Question 17

DNA replication Direction

Answer 17

5’ to 3’ direction

Question 18

Leading Strand

Answer 18

Built continuously towards replication fork

Question 19

Lagging Strand

Answer 19

Built discontinuously (in sections) AWAY from the replication fork

Question 20

Sections are called

Answer 20

Okazaki fragments

Question 21

Linear chromosome replication issue

Answer 21

Unable to Synthesize lagging strand to the end

Question 22

Solution to Issue

Answer 22

Add extra non-coding DNA (telomeres) to end

Question 23

Telomeres added by

Answer 23

Enzyme telomerase

Question 24

Telomere only occurs in

Answer 24

Gametes, stem cells, and Cancer cells