Unit 1 KA3 Gene Expression

Question 1

What is a gene?

Answer 1

A section of DNA that codes for a protein

Question 2

What is gene expression?

Answer 2

The process where specific genes are activated to produce a required protein

Question 3

What processes make up gene expression?

Answer 3

Transcription and translation

Question 4

Why is the order of amino acids in a protein important?

Answer 4

Because it determines the structure, shape and function of the protein

Question 5

What is RNA?

Answer 5

Ribonucleic Acid is a single stand of RNA nucleotides

Question 6

What components make up RNA?

Answer 6

• Ribose sugar
• Phosphate
• Base

Question 7

What are the RNA base pairs?

Answer 7

Adenine - Uracil, Guanine - Cytosine

Question 8

What is the function of mRNA?

Answer 8

Carry a copy of a section of DNA code for a specific protein from the nucleus to the ribosome

Question 8

What are the 3 types of RNA?

Answer 8

1. mRNA
2. tRNA
3. rRNA

Question 9

What is the function of tRNA?

Answer 9

Carry a specific amino acid and the bind it’s anticodon to the complimentary mRNA codon

Question 10

What is the function of rRNA?

Answer 10

Form a ribosome with proteins

Question 11

What two processes are involved in protein synthesis?

Answer 11

Transcription and Translation

Question 12

What is transcription?

Answer 12

When mRNA carries a copy of the DNA code from the nucleus to a ribosome

Question 13

Where does transcription happen?

Answer 13

In the nucleus

Question 14

What is a codon?

Answer 14

Three bases

Also called a triplet

Question 15

What does each codon code for?

Answer 15

One specific amino acid

Question 16

Where is tRNA found?

Answer 16

In the cytoplasm and ribosomes

Question 17

Every 3 bases on tRNA is called what?

Answer 17

An anti-codon

Question 18

What do the two attachment sites attach to on tRNA?

Answer 18

1. Picks up a specific amino acid
2. Binds to a specific mRNA codon (anti-codon)

Question 19

What is the enzyme that transcripes DNA into RNA?

Answer 19

RNA polymerase

Question 20

What does RNA polyerase do to the DNA strand before it starts replicating?

Answer 20

Unwinds the double helix and breaks the hydrogen bonds between the strands

Question 21

RNA nucleotides pair with complimentary base pairs in transcription

What are the complimentary base pairs for RNA and DNA?

Answer 21

Adenine to Uracil
Thymine to Adenine
Guanine to Cytosine
Cytosine to Guanine

Left column is DNA, Right column is RNA

Question 22

What carbon atom can RNA polymerase add nucleotides too?

Answer 22

The 3’ end

Just like DNA polymerase

Question 23

How are the RNA nucleotides joined together?

Answer 23

RNA polymerase joins them together to create a new sugar-phosphate backbone

Question 24

What is the mRNA transcript called right after it separates from the DNA?

Answer 24

The primary transcript.

Question 25

What are the sections of DNA that do not code for anything called?

Answer 25

Introns

Question 26

What are the sections of DNA that do code for proteins called?

Answer 26

Exons

Question 27

What is removed and what is kept as the primary transcript transformes into the mature transcript?

Answer 27

Introns are removed.
Exons are kept and spliced together

Question 28

What is the process of removing introns and joining exons together called?

Answer 28

RNA splicing

Question 29

Where does RNA splicing occur?

Answer 29

Inside the nucleus

Question 30

After the mature transcript is produced, where does it travel to?

Answer 30

From the nucleus to a ribosome

Question 31

How can different proteins be expressed from one gene?

Answer 31

Alternative RNA splicing can change which exons are retained, resulting in different mature transcripts

Question 32

Why is tRNA folded upon itself?

Answer 32

Hydrogen bonds form between the bases

Question 33

How many bases are present on a tRNA molecule?

Answer 33

3

Question 34

What is the 3 bases on a tRNA molecule called?

Answer 34

Anti-codon

Question 35

What are tRNA anticodons complimentary to?

Answer 35

mRNA codons

Question 36

What does tRNA carry to the ribosome?

Answer 36

A specific amino acid

Question 37

Where do tRNA molecules get their amino acids?

Answer 37

From the cytoplasm

Question 38

What is translation?

Answer 38

The process of tRNA anticodons aligning with mRNA codons to arrange the amino acids in the correct order in a ribosome

Question 39

After tRNA molecules have binded to mRNA, what happens?

Answer 39

The amino acids are joined together by peptide bonds to form a growing polypeptide chain

Question 40

What happens once the polypeptide chain is complete?

Answer 40

It detaches from the ribosome and will be modified

Question 41

What happens after the tRNA detaches from it’s amino acid?

Answer 41

it collects another

Question 42

When does translation began and end at?

Answer 42

Starts at a start codon
Ends at a stop codon

Question 43

Each protein is made from what?

Answer 43

Amino acids linked by peptide bonds to form polypeptide chains

Question 44

How is the sequence of amino acids in a protein determined?

Answer 44

The sequence of DNA bases determines the sequence of amino acids

Question 45

What is the structure and function of proteins determined by?

Answer 45

the sequence of amino acids determines it

Question 46

How are proteins folded?

Answer 46

Hydrogen bonds and other intermolecular forces between the amino acids form, cauing the chain to be coiled or folded

Question 47

How is the structure of the protein held together?

Answer 47

Hydrogen bonds and other interactions

Question 48

What are some types of functional proteins?

Answer 48

Enzyme
Structural proteins
Hormones
Antibodies

Question 49

How is an organism’s phenotype determined?

Answer 49

It is determined on which proteins are produced as a result of gene expression and also influenced by the environment