DNA & Proteins

Question 1

What is a primary protein structure?

Answer 1

A linear sequence of amino acids linked by peptide bonds, determines 3D configuration.

Question 2

What is a secondary protein structure?

Answer 2

The alpha helix and beta-pleated sheet.

Question 3

What is a tertiary protein structure?

Answer 3

Overall 3D conformation of protein.

Question 4

What is a quaternary protein structure?

Answer 4

3D structure of a protein composed of multiple subunits.

Question 5

What is haploinsufficiency?

Answer 5

Half the amount of protein product is produced.

Question 6

What is Knudson’s two hit hypothesis?

Answer 6

Where a normal gene just needs 1 mutation for abnormal protein to by produced by both.

Question 7

Properties of a peptide bond?

Answer 7

Very stable, flexible around carbons, partial double bond, usually 1 preferred conformation.

Question 8

What are the 5 forces holding proteins together?

Answer 8

Van der Waal, hydrogen, hydrophobic, ionic, disulphide.

Question 9

What are immunoglobulins?

Answer 9

Antibodies that are large, Y-shaped protein produced mainly by plasma cells that is used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses.

Question 10

How many bonds can A-T make?

Answer 10

2

Question 11

How many bonds can G-C make?

Answer 11

3

Question 12

Which direction does DNA polymerase read DNA

Answer 12

5’-3’ Direction.

Question 13

What is RNA primer?

Answer 13

Adds an additional RNA primer that gives DNA polymerase a starting point.

Question 14

What are the 2 strands of DNA called once opened?

Answer 14

Leading and lagging strand.

Question 15

What does P53 do?

Answer 15

Detects DNA damage and initiates repair mechanisms, pauses cell cycle until repair is carried out, if not fixed it commands call to commit suicide.

Question 16

What are the 4 bases in DNA?

Answer 16

adenine (A), cytosine (C), guanine (G), or thymine (T).

Question 17

What are tge 4 bases in RNA?

Answer 17

Adenine, Guanine, Uracil and Cytosine

Question 18

Which base is swapped in RNA

Answer 18

Thymins in DNA is swapped for uracil in RNA

Question 19

What are the 2 parts of protein synthesis?

Answer 19

Transcription and translation.

Question 20

What is transcription?

Answer 20

Transcription is the first step in gene expression. It involves copying a gene’s DNA sequence to make an RNA molecule.
Transcription is performed by enzymes called RNA polymerases, which link nucleotides to form an RNA strand (using a DNA strand as a template).

Question 21

What are the 3 steps of transcription?

Answer 21

Initiation: RNA polymerase binds to a sequence of DNA called the promoter once bound, RNA polymerase separates the DNA strands, providing the single-stranded template needed for transcription.
Elongation: One strand of DNA, the template strand, acts as a template for RNA polymerase. As it “reads” this template one base at a time, the polymerase builds an RNA molecule out of complementary nucleotides.
Termination: Sequences called terminators signal that the RNA transcript is complete. Once they are transcribed, they cause the transcript to be released from the RNA polymerase.

Question 22

What is translation?

Answer 22

In translation, the codons of an mRNA are read in order (from the 5’ end to the 3’ end) by molecules called transfer RNAs, or tRNAs.
Each tRNA has an anticodon, a set of three nucleotides that binds to a matching mRNA codon through base pairing. The other end of the tRNA carries the amino acid that’s specified by the codon.

Question 23

What are the 3 steps of translation?

Answer 23

Initiation (“beginning”): in this stage, the ribosome gets together with the mRNA and the first tRNA so translation can begin.
Elongation (“middle”): in this stage, amino acids are brought to the ribosome by tRNAs and linked together to form a chain.
Termination (“end”): in the last stage, the finished polypeptide is released to go and do its job in the cell.

Question 24

What are the 2 types of nucleic acid and what are their functions?

Answer 24

DNA, RNA. Responsible for storage, expression, transmittion of genetic information.

Question 25

Triplets that dont specify for amino acids are called?

Answer 25

‘Stop signals’

Question 26

The _____ deicdes which DNA strand is used?

Answer 26

Promoter

Question 27

A 3 base sequence in RNA that specifies for an amino acid is called a ____?

Answer 27

Codon

Question 28

What are coding and non coding sequences called?

Answer 28

Coding: Exons

Non coding: Introns

Question 29

What happens in splicing?

Answer 29

Removal of introns, after splicing RNA is called mRNA. Occurs in the nucleus and is performed by proteins and RNA known as a spliceosome.

Question 30

tRNA 3 letter code sequence is called an ____?

Answer 30

Anticodon