Bio 30 DNA quiz

DNA

Deoxyribonucleic Acid

Watson and Crick

1953; concluded double helix structure; became accepted as molecular structure of DNA

Hershey and Chase

1952; used radioactive labeling to conclude DNA was genetic material not proteins

Chargaff

1949; discovered that DNA contains equal amount of A/T and C/G (pyrimidines = purines)

Avery, McCarty, Macleod

1944; identified Griffiths transforming principle as DNA

Frederick Griffiths

1928; discovered bacteria can transfer genetic information but didn’t know the agent of transformation

A deoxyribose sugar unit, A phosphate unit, and a nitrogen base

The DNA molecule is a "Double Helix", made up of nucleotide's. The nucleotide's is composed of?

Sugar-phosphate backbone

The deoxyribose sugar and phosphate unit form the outside of the molecule, called the?

The "rungs" of a ladder

The nitrogen bases are the inside of the molecule

4 Nitrogen bases in DNA

Adenine (A), Guanine (G) are called purines (double ringed structures). Thymine (T), and Cytosine (C) are called pyrimidines (single ringed structures)

Complementary base pairs

Refers to the hydrogen bonded, nitrogenous base pairs of adenosine and thymine, and of cytosine and guanine in the DNA double helix, or the base pairs of adenosine and uracil and cytosine and guanine in hybrid molecules that link complementary strands of RNA and DNA.

Chargaff's Rule

This person found that the nucleotides are not present in equal amounts. Instead, the nucleotides are present in varying, but characteristic proportions. This person found that the amount of adenine in any sample of DNA is approximately equal to the amount of thymine and the amount of cytosine is always approximately equal to the amount of guanine. The relationship is known as?

Rosalind Franklin

1953; bombarded DNA with x rays to determine DNA’s helical structure

3 things that make up a nucleotide

*Deoxyribose sugar unit

*Phosphate unit

*Nitrogen base

Purines

(Double ringed structures)

*Adenine

*Guanine

Pyrimidines

(Single ringed structures)

*Thymine

*Cytosine

Human Genome

(Sum of all DNA carried in each cell) is made up of 3 billion base pairs and is composed of 20000 - 25000 genes

Genes

Each chromosome is made up of DNA are called? (These code for proteins and polypeptides)

Non-sense DNA/Introns

Non-coding sections of DNA are often referred to as?

Semi-Conservative

DNA replication is called? because each DNA molecule has one strand from the original DNA molecule and one new strand

3 Stages of DNA replication

*Initiation

*Elongation

*Termination

5 to 3

Replication occurs in a ___ to ___ direction?

Helicases

Unzips the DNA in order for the DNA to make a replication of itself. It unwinds the parental double helix.

Single-Strand binding

Proteins that protect and bind to the DNA strands and keep them separated.

DNA Polymerase III

-Replicates DNA molecules to build a new strand of DNA.

-During DNA replication, an enzyme that slips into the space between the two strands, uses the parent strands as a template and adds nucleotides to make complementary strands

DNA Polymerase I

removes RNA primers to replace them with DNA nucleotides

Primase

creates primer (comes in and makes RNA primers on both strands to help DNA polymerase get started)

Leading Strand

This strand is synthesized continuously in the 5 to 3 direction by DNA polymerase.

Lagging Strand

Is synthesized discontinuously. Primase synthesizes a short RNA primer, which is extended by DNA polymerase to form an Okazaki fragment.

Okazaki Fragments

short Pieces of DNA that aren't properly synthesized

RNA primer

It starts the process of getting DNA polymerase to do it's job

DNA ligase

Glues together the Okazaki fragments until the DNA polymerase properly synthesizes.

RNA

*Ribonucleic Acid (Single Stranded Molecule)

Contains Ribose sugar instead of deoxyribose

Does not contain Thymine (T) but contains Uracil (U)

U is complementary to A

Replication Bubbles

Due to the presence of various replication origins on a chromosome, these bubbles form throughout the chromosome during replication. These eventually join up forming duplicate strands.

Replication Origins

Replication begins at specific nucleotide sequences which are called.

Error Rate

DNA polymerase proof reads the new daughter DNA molecules and fixes any problems that it detects. 1 mistake per 1 billion nucleotides!

2 Stages Of Protein Synthesis

Transcription - Occurs in the nucleus

DNA - mRNA (messenger RNA)

Translation - Occurs in the cytoplasm

mRNA - Protein

3 types of RNA

*mRNA (messenger)

*tRNA (transfer)

*rRNA (ribosomal)

Topoisomerase

relieves tension from unwinding - keeps DNA from recoiling