DNA & RNA

Why do we add detergent or soap to the squished strawberries in the DNA extraction lab?

To dissolve the nuclear membrane

In prokaryotic cells, where is the DNA found in the cell?

Cytoplasm

What was the source of your DNA in the DNA extraction lab?

DNA contained in your cheek cells

Which nitrogenous bases are pyrimidines?

* Cytosine
* thymine
* uracil

Which nitrogenous bases are purines?

* Guanine


* Adenine

What are the nucleotides made of?

* Sugar
* phosphate
* nitrogen base

Guanine bonds with ________.

Cytosine

The shape of an entire DNA molecule is?

Double helix

Which parts of the nucleotide are connected by a covalent bond?

* Sugar group
* phosphate group

What type of bond connects nitrogenous bases?

Hydrogen bonds

What is similar between a strawberries, DNA and human DNA?

* The “backbone” is made of sugars and phosphates
* The number of strands in the DNA molecule

Adenine bonds with _______

Thymine

Cytosine bonds with ________

Guanine

Thymine bonds with ______

Adenine

\
Why do we had alcohol to the solution of detergent and strawberries in the DNA extraction lab?

To isolate the DNA, which is repelled by alcohol

Why do we smash the strawberry very well for a few minutes in the DNA extraction lab?

To the break the cell walls

What is the sugar in DNA?

deoxyribose

What is the sequence of DNA bases that would pair with this partial strand— ATG TGA CAG?

TAC ACT GTC

In eukaryotic cells, where is DNA found in the cell?

Nucleus

What about a strawberries DNA is different from your human DNA?

* The arrangement of the bases

What part of the DNA molecule makes up the rungs of the ladder?

Nitrogenous bases

X outlines a(n)

Nucleotide

Identify #2

Deoxyribose sugar

Identify #1

Base pairs

Identify #3

Phosphate

Identify #4

Nucleotide

A single subunit of DNA is called a:

Nucleotide

What is an organism’s genome?

all the genes in an organism

What are genes?

Information about how cells function and information about characteristics

What is the genome made up of?

chromosomes and chromatin

What are chromosomes made of?

Nuclear DNA

What is in the prokaryotic genome?

singular circular DNA molecule

What is the eukaryotic genome made of?

multiple chromosomes and histones

What are histones?

The silver thing wrapping around

They help “pack in” the genetic material

Wrap or spool the DNA into nucleosomes

What does DNA stand for?

Deoxyribonucleic Acid

What is the structure of DNA?

Double helix and nucleotides

What nucleotides made of?

Sugar, Phosphate, Nitrogenous Base

Which bases are purines?

Adenine and Guanine

What bases are the pyrimidines?

thymine, cytosine, and uracil

Where is uracil located?

in RNA

What is the formation of the double helix?

sides and rungs

What are the sides of the double helix made out of?

sugar (deoxyribose) and phosphate group

What are the rungs of the double helix made of?

nitrogenous bases

What are the two sides of the DNA ladder held together with?

hydrogen bonds?

How many hydrogen bonds hold Adenine and Thymine together?

2 hydrogen bonds

How many hydrogen bonds hold Cytosine and Guanine together?

3 hydrogen bonds

What forms 2 complimentary sides to the DNA ladders?

the base pairings

How many base pairs are in each full turn of the helix?

10

Describe the chains that run in opposite directions

One strand has an exposed phosphate and one strand has an exposed hydroxyl group (-OH)

What is mitochondrial DNA (mtDNA)?

genetic material unique to the mitochondria

What does mitochondrial DNA contain?

Contains information for 37 genes. The instructions for making enzymes in ATP production and for making transfer and ribosomal RNA.

Who is mitochondrial DNA inherited from?

the mother, it is a key indicator for tracing human heritage and migrations

What are the key components in the construction of a DNA molecule?

Deoxyribose, Phosphate, Hydrogen Bonds, Nitrogen Bases (Purines and Pyrimidines), the Nucleotide made of the sugar, phosphate, and the base.

What is the purpose of replication?

A way to copy the DNA during cell division. The cell can’t reproduce or grow without replication.

What kind of process is the replication process?

Semiconservative Process

What is a semiconservative process?

Each side pairs with a new “side”

It keeps 1/2 the DNA to make new DNA

What is the replication process (generally)?

Each side of the helix serves as a template for copying

What results from the replication process?

2 new strands that are identical to the original strand

Where does replication begin?

specific sites on the DNA molecule

What are the spots replication begins at called?

Origins of Replication

What is the first step of replication?

The enzyme DNA **helicase** breaks the bonds between the nitrogenous bases?

What does the enzyme DNA helicase do?

destabilizes hydrogen bonds

What is the second step of replication?

the DNA strand unzips and forms a replication fork

What is the third step of replication?

The SSB protein joins in

What does SSB stand for?

Single Strand Binding protein

What is the role of SSB?

prevent the double helix from reforming

What is step four of replication?

Free nucleotides bond to the single strands using DNA polymerases

How do free nucleotides bond to the single strands in the 5’ to 3’ direction?

It starts at the 5’ end and adds nucleotides only to the 3’ end

Which strand goes in the 5’ to 3’ direction?

leading strand

Which strand is more efficient and how fast is it?

the leading strand (5’ to 3’) with about 1200 nucleotides per minute

What is the fifth step of replication?

On the lagging strand, RNA primer is used to start replication at the 3’ end. RNA primer is formed by DNA primerase and is quickly replaced by DNA polymerases.

Describe the leading strand in replication.

(5’-3’) Adds nucleotides to the 3’ end of the NEW strand, toward the replication fork, DNA polymerase, SMOOTH

Describe the lagging strand in replication.

(3’-5’) Adds nucleotides to the 3’ end of the NEW strand, going AWAY from the replication fork, short segments at a time, DNA polymerase, DISCONTINUOUS

What are the short segments formed on the lagging strand called?

Okazaki fragments

What is the sixth step of replication?

DNA polymerases also “proofread” filling in gaps or fixing mismatched sections

What is the seventh step of replication?

DNA ligase zips up the new helixes (re-establishes hydrogen bonds)

What is the role of DNA polymerases?

helps free nucleotides bond to the single strands and “proofread” the replicated DNA

What is the role of DNA primerase?

create the RNA primer to start replication on the lagging strand

What is the role of DNA ligase?

re-establish the hydrogen bonds in DNA

How many points of origins of replication are there?

There are multiple on one strand of DNA

Describe what happens because of multiple points of origin of replication

more than one replication fork per strand of DNA, the replication continues until meets another origin, speeds up the process

What is the end result of replication?

2 new identical DNA strands are formed

What are Telomeres? (physical)

protective end caps

T/F Telomeres contain protein coding genes

False

What are telomeres? (in terms of dna)

short simple noncoding DNA sequences that repeat many times

What is the role of telomeres?

protective advantage due to the lagging strand not being completely replicated

What does the length of a telomere sequence depend on?

cell type and age of the cell

What makes each organism or individual unique?

nucleotide sequences in DNA

What do similarities in DNA code show?

evolutionary relationships

What are proteins made from?

long chains of amino acids

What makes up the sequence for protein synthesis?

nitrogenous bases in DNA (&RNA)

How many Amino Acids are there?

20

What are the functions of proteins?

growth, repair, and control reactions

How do we get 20 amino acids from just 4 bases?

Bases are put together in different combinations of three.

What is a codon?

combination of three bases is used to code for all the amino acids

What is codon specific too?

mRNA

What are the two special codons?

Stop and Start Codons

What is the role of a start codon?

Signals the beginning of Transcription/Translation

What is the role of a Stop Codon?

Signals the end of the process of Transcription/Translation

What do codons tell us about all organisms?

They demonstrate that ALL organisms are linked to a common ancestor