Topic 3 - Gene Expression Flashcards Preview

Higher Human Biology Unit 1 > Topic 3 - Gene Expression > Flashcards

Flashcards in Topic 3 - Gene Expression Deck (41):
1

What regulation controls gene expression?

Transcription and Translation

2

Structure of RNA

Single stranded, with nucleotides

3

Bases in RNA and who they're paired with

Uracil with Adenine, Guanine with Cytosine

4

Difference in nucleotides between RNA and DNA structure

The bases (uracil instead of thymine), the sugar (ribose instead of deoxyribose)

5

What's the function of mRNA

Carries a copy of the DNA code from the nucleus to the ribosome

6

What's the function of rRNA

Along with proteins, it forms the ribosome

7

What's the function of tRNA

Carries a specific amino acid

8

Primary Transcript of DNA into mRNA

A copy of information is made in the nucleus from a DNA molecule on to a RNA molecules called mRNA

9

First stage of Transcription of DNA Into mRNA

RNA polymerase moves along DNA unwinding a section of the double helix

10

What happens to the sugar phosphate bonds during transcription

They form between adjacent RNA nucleotides

11

What is required for transcription?

ATP and RNA polymerase

12

Complementary Base Pairing takes place during Transcription. What does this mean?

Free nucleotides pair with DNA bases, guanine and cytosine, uracil and adenine

13

What happens in RNA splicing? (To the introns)

The introns of the primary transcript of mRNA are non- coding and are removed

14

What happens in RNA Splicing? (To the Exons)

They are coding regions and are joined together to form mature transcript

15

How is gene expression influenced?

By intra and extra - cellular environmental factors

16

A Polypeptide Chain

A short chain of 6 - 8 amino acids joined together

17

What is mRNA translated into and where is it translated?

It's translated into a polypeptide chain at a ribosome

18

Why does tRNA fold during transcription?

Due to base pairing to form a triplet anticodon site and an attachment site for a specific amino acid

19

What is mRNA transcribed from?

DNA in the nucleus and translated into proteins by ribosomes in the cytoplasm

20

Introns

Non-coding regions of genes

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Exons

Coding regions of genes

22

What do triplet codons on mRNA and anticodons translate?

They translate the genetic code into a sequence of amino acids

23

Start codon

The first three bases on a mRNA strand (i.e the first codon)

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Stop Codon

The last codon

25

What happens when the translation reaches the stop codon?

The ribosome releases the newly synthesised polypeptide chain

26

ATP in Translation

It provides energy for the process

27

What will the sequence of the codons in the mRNA strand determine?

The amino acids in the polypeptide that will be synthesised

28

How do anticodons on tRNA relate to the codons on mRNA?

They are complementary to each other

29

Hydrogen bonds form between..

Bases

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Peptide bonds form between..

Amino acids

31

Where does transcription take place?

The nucleus

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Where does translation take place?

Ribosome

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What happens to a protein after translation?

The protein is modified

34

How is the protein modified after translation?

The cutting and joining of polypeptide chains or by the addition of a carbohydrate or a phosphate group to the final protein molecule

35

Structural similarities with mRNA and tRNA

Both contain the bases A,U,C and G

36

Structural differences with mRNA and tRNA

tRNA is folded, when mRNA is not. tRNA has base pairing, mRNA doesn't. mRNA is single-stranded and tRNA is double-stranded

37

Transcription

Copying of the DNA code onto the mRNA

38

Translation

Converting the information given on the mRNA into a sequence of amino acids

39

Triplet

Sequence of bases specifying one amino acid

40

Codon

Triplet of bases on mRNA

41

Anti-Codon

Triplet of bases on tRNA