3. Gene expression and RNA notes

Question 1

What functions as an instruction to make protein.

Answer 1

The DNA sequence of a gene contains the instructions for building a protein: proteins are involved in the expression of a trait.

Question 2

instruction What is the monomer of a protein?

Answer 2

Amino Acids are monomers of a protein.

Question 3

How many different amino acids are there

Answer 3

There are 20 different amino acids linked in different orders.

Question 4

Differentiate between DNA& RNA

Answer 4

DNA is double-stranded- Double helix and RNA is single-stranded.

Question 5

Describe the structure and function of mRNA

Answer 5

1. Long Straight hain of nucleotides made in the nucleus.
2. Copies DNA & leaves through nuclear pores.
3. contains the Nitrogen Bases A, G, C, and U (no T)
4. Carries the information for a specific protein.
5. Made up of 500 to 1,000 nucleotides long.

Question 6

What are codons

Answer 6

A sequence of 3 bases in an mRNA that codes for an amino aid of stop signal.

Question 7

Which codons are start and which codons are stop codons.

Answer 7

AUG-Start codon
UAA, UAG, UGA- stop codons.

Question 8

Describe the function of rRNA

Answer 8

1. Makes up the ribosome along with proteins
2. Globular in shape
3. Ribosomes are found in the cytoplasm and on the rough ER
   4.rRNA is single strand 100 to 3,000 nucleotides long
4. Made inside the nucleus of a cell
5. Site of protein synthesis.
   Overall: Build protiens

Question 9

Describe the structure and fucntion of tRNA. Mention anitcodons

Answer 9

1. Clover-leaf shape
2. Single-stranded molecule with attachment site at one end for an amino acid.
3. The opposite end has three nucleotide bases called the anticodon
4. The 3 bases of an anticodon are complementary to the 3 bases of a codon.
   EX: Codon: ACU
   Anticodon UGA

Question 10

What are the steps that allow the information in DNA to be expressed as a phsyial trait.

Answer 10

DNA—mRNA—Protein

Question 11

Where is DNA found

Answer 11

Dna is found in the nucleus and remains there.

Question 12

What happens during transcription and translation.

Answer 12

Transcription: a gene region in one strand of DNA serves as a template for assembling a strand of mRNA.
- Happens in the nucleus

Translation:the ribosomes decipher the message in mRNA and use it to assemble amino acids into a protein.
-Happens in the cytoplasm in the ribosomes.

Question 13

RNA nucleotides have:

Answer 13

Phosphate group, sugar ribose, nitrogenous base
- Adenine
- Guanine
-Cytosine
-Uracil
A & U C & G

Question 14

What are the types of RNA

Answer 14

Messenger RNA (mRNA)
- A copy of DNA’s code and carries the genetic informations to ribosomes
Transfer RNA (tRNA)
- Transfers amino acids to the ribosome.