Topic 1.3

Question 1

What’s a nucleotide?

Answer 1

A monomer for DNA

Question 2

What are the 3 parts of a nucleotide?

Answer 2

Phosphate, Pentose sugar, Nitrogen base

Question 3

How does a nucleotide form?

Answer 3

Deoxyribose uses a condensation reaction which creates a phosphoester bond + water

Question 4

What are the two nitrogen groups containing bases?

Answer 4

Purines and Pyramidines

Question 5

What’s the difference between a purine and a pyramidine?

Answer 5

Purines have 2 carbon rings whereas Pyramidines have 1

Question 6

What are the Purine bases?

Answer 6

Adenine and Guanine

Question 7

What are the Pyramidine bases?

Answer 7

Thymine, Cytosine, Uracil

Question 8

What is a DNA molecule composed of?

Answer 8

Pentose sugars, phosphate groups and 4 types of nitrogenous bases

Question 9

How are DNA bases held together?

Answer 9

With Hydrogen bonds

Question 10

What are the 4 bases of DNA

Answer 10

Adenine, Guanine, Thymine, Cytosine

Question 11

What are the 4 bases of RNA?

Answer 11

Uracil, Thymine, Cytosine, Adenine

Question 12

What is stage 1 of DNA replication?

Answer 12

Helicase enzymes separates the two DNA strands
Breaks hydrogen bonds between bases

Question 13

What’s stage 2 of DNA replication?

Answer 13

*Two strands of DNA are catalyzed by DNA polymerase
*Uses the ‘parent’ strands as templates
* Reads the sequence of bases in triplet and adds complimentary bases to form new strands.

Question 14

What’s Stage 3 of DNA replication?

Answer 14

*DNA polymerase reads parent strand
*Builds leading strand towards the replication fork

Question 15

What’s Stage 4 of DNA replication?

Answer 15

Once the mRNA copies the whole gene it detaches and leaves the nucleus through the nuclear pores and moves to the ribosome

Question 16

What’s Stage 1 of protein synthesis?

Answer 16

mRNA is attached at the start codon, in triplet

Question 17

What’s Stage 2 of protein synthesis?

Answer 17

tRNA molecules contain a sequence of 3 bases(anticodon) . The tRNA molecule will bond with a complementary codon on the mRNA strand

Question 18

What’s Stage 3 of protein synthesis ?

Answer 18

Ribosomes move along mRNa, tRNA moves in carrying corrosponding amino acid. Two amino acids are then joined together by peptide bond

Question 19

What’s Stage 4 of protein synthesis?

Answer 19

Another tRNA moves into the ribosome-the first tRNA molecule is released(free to collect another amino acid from the cytoplasm

Question 20

What’s Stage 5 of protein synthesis?

Answer 20

This keeps happening until a stop codon is reached on the strand

Question 21

What’s a mutation?

Answer 21

Change in amount or structure of the chromosomes

Question 22

What’s Gene/point Mutation?

Answer 22

Change in the base sequence of a gene

Question 23

What’s Non-disjunction?

Answer 23

Failure of homologous chromosomes to separate properly during meiosis

Question 24

What’s translocation?

Answer 24

When a piece of chromosome breaks off and is transferred to another chromosome

Question 25

What are the Types of mutation?

Answer 25

Subsition: *Silent *Mis-sense *Nonsense Frameshift: *Insertion *Deletion

Question 26

What are the definitions of the subsition type of mutation?

Answer 26

Silent- change in base still codes for amino acids Mis-sense- Change in base codes for 1 different amino acid Non-Sense- Change in base codes for stop codon

Question 27

What are the definitions for the Frameshift type of mutation?

Answer 27

Insertion: Adds 1 base Deletion: Loses 1 base

Question 28

What's the definition of genetic code?

Answer 28

Sequence of bases along DNA

Question 29

What bonds nucleotides together?

Answer 29

Condensation reaction

Question 30

Describe the structure of a DNA section

Answer 30

A hydrogen bond connects the bases, attached to the base is the Deoxyribose(sugar), attached to that is the phosphate

Question 31

What's the role of mRNA in protein synthesis?

Answer 31

To create a complementary single strand copy of the DNA which leaves the nucleus

Question 32

What's the role of tRNA in protein synthesis?

Answer 32

To transport correct amino acids to the ribosome

Question 33

How are ribosomes formed?

Answer 33

rRNA combines with proteins in the nucleolus

Question 34

What's the function of a ribosome during protein synthesis?

Answer 34

Translating genetic code transcribed from mRNA into an amino acids sequence

Question 35

What's a codon?

Answer 35

A triplet of nucleotides which code for an amino acid

Question 36

What's the name of the process that copies DNA into RNA?

Answer 36

Transcription

Question 37

How does mRNA leave the nucleus?

Answer 37

Through the nuclear pore

Question 38

What happens at the ribosome?

Answer 38

Translation- mRNA attaches onto polypeptide chain

Question 39

How does the protein (folded up polypeptide chain) move from the RER to the Golgi?

Answer 39

Transport vesicle

Question 40

How does the protein enter the Golgi?

Answer 40

Fuses with the cis face of the Golgi

Question 41

How do the proteins leave the Golgi?

Answer 41

Secretory vesicles pinched off at the end