2.1.3 Nucleotides nucleic acids

Question 1

draw and label the structure of a nucleotide, make sure they are combines to te corrects carbons :D

Answer 1

https://docs.google.com/document/d/1YAqlrSiS9YOn4vkAJhGgEGGAk9AOO-pf1GieocY6v4M/edit?usp=sharing

Question 2

what is the structure of DNA

Answer 2

Anti parallel backbones

complimentary bases

Question 3

What are the purines?

Answer 3

Adenine and Guanine

Question 4

what are the Pyrimidines?

Answer 4

Thymine and cytosine

Question 5

How many bonds does each nucleotide base pair have?

Answer 5

Adenine + Thymine = 2 bonds

Guanine + Cytosine = 3 bonds

Question 6

what is a codon?

Answer 6

A triplet base on mRNA that codes for an Amino acid

Question 7

What is a mutation?

Answer 7

A random change to genetic material

-can alter the structure/number of chromasomes

Question 8

What is a gene mutation?

Answer 8

A gene mutation is a change in DNA

• DNA is stable, though spontaneous mutations can occur during DNA replication
• Can also happen in mitosis

Question 9

what are the 2 main classses of mutation?

Answer 9

• substitution mutation:one base replaces another

- insertion or deletion mutation: parts of the DNA are shifted/ replaced and can have ,major effects on the organism

Question 10

what does it mean if DNA is degenerate?

Answer 10

amino acids in the DNA can be coded for by different combinations of triplet bases

Question 11

What are the 3 types of substitution mutations?

Answer 11

1) Nonsense
2) Silent
3) Missence

Question 12

what are the differences between DNA and RNA?

Answer 12

• RNA uses Uracil instead of thymine

- RNA is a single strand

Question 13

What is mRNA

Answer 13

• Mae in the nucleus and is small enough to fit through the nuclear pores
• Contains a copy of the DNA that codes for a protein/polypeptide that will be synthesised at a ribosome
• uses uracil instead of thymine and is single stranded

Question 14

what is tRNA?

Answer 14

• Singular stranded, however folds into a clover shape

- Contains an Anticodon that is hydrogen bonded to it

Question 15

What are the 3 points where gene expression is controlled?

Answer 15

• Transcription
• Post-transcription
• translation

Question 16

What is the process of Transcription?

Answer 16

-DNA Helicase separates the 2 strands of DNA by breaking H-Bonds
-RNA polymerase moves along one of the DNA strands causing nucleotides to
join with complementary bases
-Adenine joins with uracil instead of thymine
-As RNA polymerase moves along, the DNA strands joins behind it

Question 17

How does the RNA plymerase know when to binf?

Answer 17

There is a promotor region in the DNA, asweel as a terminating region, to that specific sections can be transcribed

Question 18

what is a transcription factor?

Answer 18

short non-coding areas that combine with specific lengths of DNA that activates or inhibits the transcription of genes

Question 19

What are some molecules that can switch genes on and off?

Answer 19

Hormones, e.g. Oestrogen

Question 20

what are introns?

Answer 20

A section of a gene thst does not code for an Amino acid

Question 21

what are exons?

Answer 21

A section of a gene that codes for an amio acid

Question 22

How are Introns removed from pre-mRNA?

Answer 22

We use SPLICING

-this is when the introns are removed and the functional exons are joined together