DNA (full/test)- Bio 22-23

What does DNA stand for?

Deoxyribonucleic Acid

Genes

segments of DNA that code for particular body proteins

Introns

Genomes that do not code or "Junk DNA"

Exons

DNA that codes for proteins

Histones

Proteins that keep DNA tightly coiled

Humans have how many chromosomes?

46

How many gametes do humans have?

23

DNA is a polymer that is made up of......

Nucleotide monomers

Nucleotide monomers consist of...

• Deoxyribose sugar

• Phosphate molecule

• Nitrogen bases

Nitrogen Bases are...(DNA)

• Adenine

• Thymine

• Guanine

• Cytosine

When extracting DNA, what does Detergent do?

break open that cell membrane and nuclear membrane

“A” stands for…

Adenine

“T” stands for…

Thymine

“G” stands for…

Guanine

“C” stands for…

Cytosine

The base pairs would type…

200 telephone books (3 billion base pairs long)

Nucleotide monomers

monomer that makes up DNA

What is the purpose of adding meat tenderizer?

to extract the protein from the nucleus and to stretch the DNA

What happened when the cold ethanol was added?

the DNA floated to the top

Would it make a difference if warm ethanol was added.

There would be less DNA floating to the top.

How to isolate DNA from fruit?

1. mush fruit

2. add dish soap, salt, & meat tenderizer

3. mush again

4. separate juice with coffee filter

5. add juice to cold alcohol

Describe in detail how DNA was extracted from a cheek cell (7 steps)

1. Salt water is swished around in the mouth for 30 seconds

2. Spit salt water out back in cup

3. Pour salt water into a test tube containing 1 teaspoon 25% liquid detergent

4. Cap the test tube and gently rock it back and forth for 2-3 minutes

5. Pour 1 teaspoon of 95% percent ethanol down the side of the test tube

6. The the test tube sit for 1 minute

7. Place a rode into the rube and gently pick up the DNA

How was the strawberry DNA extraction different from the cheek cell DNA extraction?

• had to break the strawberry’’s cell wall

• had to use meat tenderizer

What are the sides of the DNA ladder made up of?

The sides of the DNA ladder are made up of deoxyribose sugars and phosphate molecules.

What type of bond holds the nitrogenous bases together?

Hydrogen bonds

3 ways RNA differs from DNA.

1. RNA is single stranded

2. RNA codes for amino acids

3. RNA contains U instead of T

List the four nitrogenous bases found in RNA.

Adenine, Uracil, Guanine, Cytosine

What is transcription and where does it occur? 

the process of transferring info from a strand of DNA to a strand of RNA. This occurs in the nucleus.

Three RNA bases together is known as a….

Codon

What is translation and where does it occur?

the assembly of a protein by the code provided by the mRNA. This occurs in the ribosome.

Start Codon

AUG

Stop Codon

UGA

“U” stands for

Uracil

What sugar is found in DNA?

Deoxyribose sugar

 How many nitrogenous bases do you have in one of your cheek cells?

3 Billion

What role does mRNA play in protein synthesis?

mRNA brings the message of DNA to the ribosome and has the instructions for making proteins. 

Why is transcription necessary?

DNA needs to be protected in the nucleus so the info is transcribed into RNA. RNA is also single stranded so it can fit through the nucleus.

A chain of amino acids is called a….

Protein

The three bases on the tRNA molecule that match up with the mRNA codon is called a…..

anticodon

How does the ribosome know when to release the polypeptide/protein?

When the ribosome reaches a stop codon

The order of transcribing DNA to a protein

1. mRNA is transcribed from DNA in the cell’s nucleus

2. mRNA leaves the nucleus and enters the cytoplasm

3. the ribosome attaches to the start codon of the mRNA molecule

4. tRNA carries the amino acid to the ribosome

5. ribosome encounters the stop codon and falls off the mRNA

6. completed protein is released and ready for use

What charge does DNA have?

A negative charge

Do larger DNA fragments move more quickly or slowly through the gel?

Slowly

Mutation

change in a DNA sequence

Point mutation

one letter is exchanged for another

A point mutation is also called….

substitution

Frameshift mutation

the insertion or deletion of a base

Missense mutation

The wrong amino acid is coded for

Nonsense mutation

Premature stop codon is coded for

Silent Mutation

Amino acid that is coded for is the same