Chapter 3 - Cell Protein Production

Question 1

Name some proteins found within the body

Answer 1

• Insulin
• Haemoglobin
• Actin ans Myosin

Question 2

What is synthesis?

Answer 2

Synthesis is the combining of small molecules to make larger molecules

Question 3

What does synthesis require?

Answer 3

Matter and Energy

Question 4

Why is synthesis of proteins important to cell metabolism?

Answer 4

The synthesis of proteins is a very important part of cell metabolism because proteins make up much of the structural material of a cell, and special proteins called enzymes control the cell’s chemical reaction.

Question 5

The types of proteins a cell can make is determined by…

Answer 5

genes

Question 6

What is transcription?

Answer 6

Transcription is the process by which the mRNA is formed using the code in a DNA molecule

Question 7

What is the first stage of transcription?

Answer 7

The two strands of the DNA molecule seperate and the RNA polymerase begin to make mRNA.

Question 8

What is the second stage of transcription?

Answer 8

RNA polymerase joins nucleotides with bases that are complementary to those on the DNA template strand.

Question 9

What is the third stage of transcription?

Answer 9

mRNA is formed with bases that are the same as the coding strand of DNA. mRNA moves into the cytoplasm through a nuclear pore.

Question 10

What are introns?

Answer 10

Introns are non-coding sequences.

Question 11

What are exons?

Answer 11

Exons is the base sequence that code for amino acids

Question 12

What happens after the mRNA has been made?

Answer 12

The mRNA that has been copied will contain both introns and exons, the introns must be removed before the mRNA can be used to assemble amino acids into a protein.

Question 13

What is a codon?

Answer 13

A codon is a sequence of three basis in the mRNA molecule that are thr code for an amino acid.

The bases of the codon are complementary to those in the template strand and the same as those in the coding strand of the DNA.

Question 14

What is transcription?

Answer 14

Transcription is the production of a protein using the information that is coded in the mRNA molecule.

Question 15

tRNA is made of …

Answer 15

A chain of nucleotides that pair with each other to give the molecule a characteristic shape

Question 16

What is an anti-codon?

Answer 16

The three bases on a tRNA molecule that are the ‘mirror image’ of a codon

Question 17

what is a start codon?

Answer 17

When a ribosome is reading the code in the mRNA, it is triggered to start joining amino acids together by the start codon.

Question 18

For each bond formed between the amino acids, the energy from the breakdown of one ATP molecule is required.

What is ATP?

Answer 18

Adenosine Triphosphate is a molecule that stores energy for use in cell processes.

Question 19

Summerise protein synthesis

Answer 19

Transcription

• two strands sperate
• mRNA form bases complementary to those on the DNA strand
• mRNA undergoes modicfication - inrons are removed leaving eons
• mRNA travels from the nucleus to the cytoplasm

Translation

• mRNA attaches to ribosome
• ribosome moves along the mRNA, reading the code. the start codon begins making the protein
• a tRNA with a matching anticodon brings the correct amino acid
• amino acids bond together to form the protein

Question 20

What is gene expression?

Answer 20

Gene expression is the production of a protein using the information encoded in a gene

Question 21

what is Gene regulation?

Answer 21

Gene regulation is the control of the effectiveness of any of the stages of gene expression by controlling and determining which genes are switched on and off, when, and how long for

Question 22

When can gene expression be regulated?

Answer 22

Gene expression can be regulated at the transcription stage, at the translation stage or by the later modification of the protein that is formed.

Question 23

What is a promoter gene?

Answer 23

A promoter gene is a gene that facilitates transcription from one or more naerby structural genes; part of an operon

Question 24

What is a regulator gene?

Answer 24

A regulator gene is a gene that is able to produce proteins that bind to the operator gene and inhibit transcription

Question 25

Why is protein shape important?

Answer 25

Protein molecule shape is critical for the correct functioning of the protein. A slight change in the structure can prevent the protein from functioning normally.

Question 26

What are the four levels of complexity of protein structure?

Answer 26

1. Primary structure
2. Secondary structure
3. Tertiary structure
4. Quaternary structure

Question 27

Describe the four levels of complexity of protein structure.

Answer 27

1. Primary structure: a chain of amino acids joined by peptide bonds
2. Secondary Structure: the amino acid chain forms sheets or spirals due to bonding between the different parts of the chain
3. Tertiary Structure: produced by more bending and folding of the sheets and spirals
4. Quanternary Structure: two or more chains are joined. In this diagram a molecule of haemoglobin is formed from four globular sub-units. Each of the sub-units also has a group containing iron

Question 28

If proteins are to be used outside the cell…

Answer 28

they have to be packaged for secretion from the cell in which they are made

Question 29

What happens at the edges of the golgi apparatus?

Answer 29

At the edge of the apparatus the membrane proteins pinches off to form a vesicle containing some of the modified proteins.

Question 30

What is lipid/carbohydrate synthesis?

Answer 30

Lipid: are broken down to fatty acids and glycerol

carbohydrates: are broken down into glucose