Biochemisty/ Molecular Biology

What organelle replicates DNA?

Nucleus

Which organelle transcribes RNA?

Nucleus

Which organelle translates mRNA into proteins?

Ribosomes

Which organelle deals with protein secretion?

Gogli Complex

What is the Central Dogma?

replication of DNA, transcription into RNA, and translation into proteins

Which direction is DNA read in?

5 to 3

Which strand reads 5 to 3?

Coding strand

Which direction is the template strand read in?

Template strand

Which strand is use to make RNA?

Template Strand

What is the only difference between DNA and RNA?

Uracil is in RNA and thymine is in DNA

What is the starting code?

AUG

What does an nucleoside contain?

Heterocyclic base, pentose sugar, Phosphate ether

What is the difference between a nucleoside and a nucleotideIS RNA?

A nucleosie does NOT have a phospahte group

Is RNA or DNA less stable? Why is that?

RNA, an extra OH group ( Hydroysis)

What are the forces that hold DNA in a double helix? List them in strongest to weakest

• Covalent

  • Phosphodiester linkages

• Pi bond stacking

• Hydrophobic forces

• Watson-Crick hydrogen bonds

What Code goes with G?

C

What code goes with A?

T

What is denaturation?

Hydrophobic forces undergo heat, and the W/C bonds break. Single strands are made as a result.

What is renaturation?

W/C bonds reconnect, and sequences are put together.

What is found at the start of a gene? Why is that?

TATA box, and bc A-T has only 2 H-bonds, as opposed to 3 H-bonds

Is RNA or DNA more short lived?

RNA

What is mRNA?

Modified RNA that carries genic information to a ribosome when it exits the nucleus

How is DNA made up in terms of schematics?

1. Exon 1

2. Intron A

3. Exon 2

4. Intron B

5. Exon 3

How is mRNA transcript made up in terms of schematics?

1. Exon 1

2. Intron A

3. Exon 2

4. Intron B

5. Exon 3

6. Poly (A) tail

How is mature mRNA made up in terms of schematics?

1. Exon 1

2. Exon 2

3. Exon 3

4. Poly (A) tail

What is a semi-conservation DNA?

One strand is from the orginal DNA and the other is new

What does DNA replication consist of?

• Replication fork

• Replication

• Polarity problem

• Clean up

What does the replication fork consist of?

• Separation of parent strands

• Helicase

• SSB

• Topoisomerase

What does repliction consist of?

• Primer

• Polymerase

  • Prooreading

What is the polarity problem?

Continuous and discontinuous strands

What does the clean up in DNA replication?

• Primers

• Gaps

• Ligation

Where does repliction start on the DNA strand?

The origin

What is a helicase, and what does it do?

An enzyme and it opens the repliction fork

What is SSB and what does it do?

Single-strand binding proteins and it keeps the fork open

What are the difference types Topoisomerase and what does it overall do?

• Topo I

  • Cuts one time

• Topo II

  • Cuts two times

Relieves the tension on the DNA strands during unwinding and then rejoins them

Topoisomerase uses Ligase?

False

Where is the Primer added on the template strand?

3’ end

How are nucleotides added using DNA polymerase III?

5’ end to the 3’ end

What does DNA polymerase do in general?

• Brings in the correct nucleotide

• Proofreads the base pair connectivity

  • If wrong, exonuclease occurs

    • 3’ to 5’ ( removes the incorrect nucleoside from the 3’ end)

How is the leading strand read and how it is made?

3’ to 5’

Continuous and uninterrupted

How is the lagging strand read and how it made?

5’ to 3’

Fragments called Okazaki fragments

What does RNase H and DNA Polymerase I do?

removes primers from the Okazaki fragments and replaces them with the correct Deoxynucleotides to fill the gaps

How are the nicks “filled”?

Ligase enzymes

How does Ligase fill the nicks in the lagging strand?

uses ATP to cause a connection between 3’ OH and 5’ phosphate, releasing AMP

What are the four principles of Biomolecules?

• Carbohydrates = Simple Sugars

• Proteins = Amino Acids

• Lipids = Fatty Acids

• Nucleic acids = Nucleotides

What is the general structure of Amino Acids?

• A Amino Group

• A carboxylic Acid group

• A side Chain

  • This is the only thing that changes

Are L-amino Acids or D-amino Acids incorporated into proteins?

L-amino acids

What are the 9 essential amino acids?

• Histidine

• Isoleucine

• Leucine

• Lysine

• Methionine

• Phenylalanine

• Threonine

• Tryptophan

• Valine